Page 1
2500
Engineering
Handbook
2500 Process Controller
Version 3.7 and version 4.3 (SYSIO)
HA027115/4
March 2011
Page 2
© 2011 Eurotherm Limited
All rights are strictly reserved. No part of this document may be reproduced, modified, or transmitted
in any form by any means, nor may it be stored in a retrieval system other than for the purpose to act
as an aid in operating the equipment to which the document relates, without the prior, written
permission of Eurotherm Limited.
- - - - - - - - - - - - -
Eurotherm Limited pursues a policy of continuous development and product improvement. The
specification in this document may therefore be changed without notice. The information in this
document is given in good faith, but is intended for guidance only. Eurotherm Limited will accept no
responsibility for any losses arising from errors in this document.
Page 3
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar-11 CN27146 1
Model 2500 DIN Rail Controller
Engineering Handbook
Contents
Section No. Topic Page
SAFETY and EMC INFORMATION………………………………………………………8
1. Chapter 1 INTRODUCTION ......................................................................................... 11
1.1. ABOUT THIS HANDBOOK .......................................................................................................... 11
1.2. SYMBOLS USED IN THIS MANUAL ........................................................................................... 11
1.2.1. File Paths .................................................................................................................................................. 11
1.3. STATUS WORDS .......................................................................................................................... 12
1.4. WHAT IS THE 2500? .................................................................................................................... 13
1.5. WHAT DOES THE 2500 DO? ..................................................................................................... 13
1.6. THE COMPONENTS OF THE 2500 ........................................................................................... 14
1.7. UNPACKING THE INSTRUMENT ............................................................................................... 14
1.8. MECHANICAL INSTALLATION ................................................................................................... 15
1.8.1. DIN Rail Mounting ................................................................................................................................... 16
1.8.2. Panel Mounting ....................................................................................................................................... 16
1.8.3. Terminal Unit Installation ........................................................................................................................ 16
1.8.4. Terminal Unit Removal ............................................................................................................................ 16
1.8.5. To Fit a Module ........................................................................................................................................ 17
1.8.6. Module Removal...................................................................................................................................... 17
1.9. I/O MODULE FUNCTIONS.......................................................................................................... 18
2. Chapter 2 The IOC Module ........................................................................................ 19
2.1. OVERVIEW .................................................................................................................................... 19
2.2. OPERATING MODES ................................................................................................................... 20
2.2.1. Run Mode ................................................................................................................................................. 20
2.2.2. Configuration Mode ................................................................................................................................ 20
2.2.3. Configuration Key.................................................................................................................................... 21
2.2.4. Standby Mode ......................................................................................................................................... 21
2.2.5. Fail Mode ................................................................................................................................................. 21
2.3. CONFIGURATION PORT ............................................................................................................. 22
2.4. STATUS INDICATION .................................................................................................................. 23
2.5. INITIALISATION AND POWER ON SELF TEST ......................................................................... 24
2.6. MODBUS IOC AND TERMINAL UNIT ........................................................................................ 25
2.6.1. Connections to the RJ45 Sockets........................................................................................................... 25
2.6.2. The RJ45 Modbus Line Terminator ........................................................................................................ 26
2.6.3. The Modbus Address Switch .................................................................................................................. 26
2.6.4. Baud Rate ................................................................................................................................................. 26
2.7. PROFIBUS IOC AND TERMINAL UNIT ...................................................................................... 27
2.7.1. Connections to the Network Connectors .............................................................................................. 28
2.7.2. The Profibus Address Switch .................................................................................................................. 28
2.7.3. Profibus 9 pin Connector Line Termination .......................................................................................... 29
2.7.4. The RJ45 Profibus Line Terminator ........................................................................................................ 29
2.8. DEVICENET IOC AND TERMINAL UNIT .................................................................................... 30
2.8.1. Connections to the Terminal Unit .......................................................................................................... 31
2.8.2. DeviceNet Terminators ........................................................................................................................... 31
2.8.3. Power ........................................................................................................................................................ 31
2.8.4. The DeviceNet Address Switch .............................................................................................................. 31
2.9. ETHERNET IOC AND TERMINAL UNIT ..................................................................................... 32
2.9.1. Connections to the RJ45 Socket ............................................................................................................ 33
2.9.2. The Modbus Address Switch .................................................................................................................. 33
Page 4
2500 Controller Engineering Handbook
2 Part No HA027115 Issue 4.0 Mar -11
3. Chapter 3 iTools ........................................................................................................... 34
3.1. OVERVIEW ................................................................................................................................... 34
3.2. CONNECTING ANY 2500 TO A PERSONAL COMPUTER ..................................................... 34
3.2.1. To Connect a Single 2500 Controller to a PC ....................................................................................... 34
3.2.2. To Connect multiple 2500 Controllers to a PC ..................................................................................... 35
3.3. STARTING ITOOLS - DEVICE DETECTION ............................................................................... 38
3.4. SETTING ACCESS LEVEL ............................................................................................................ 38
3.4.1. Operating Mode ...................................................................................................................................... 38
3.4.2. Configuration Mode ................................................................................................................................ 38
3.4.3. Standby Mode. ......................................................................................................................................... 39
3.4.4. Changing Mode ....................................................................................................................................... 39
3.5. INSTRUMENT PARAMETERS ..................................................................................................... 40
3.5.1. To Display Parameters ............................................................................................................................. 40
3.5.2. To Find a Parameter ................................................................................................................................ 40
3.5.3. To Change Parameter Values ................................................................................................................. 41
3.5.4. Example: To Set Baud Rate .................................................................................................................... 41
3.5.5. Failure To Write a New Value .................................................................................................................. 41
3.6. PARAMETER AVAILABILITY AND ALTERABILITY .................................................................... 42
3.7. SETTING UP AN APPLICATION ................................................................................................. 43
3.7.1. What is a Function Block? ....................................................................................................................... 43
3.7.2. Why use Function Blocks? ....................................................................................................................... 43
3.7.3. Function Block Wiring Example .............................................................................................................. 43
3.8. DECLARING I/O MODULES ....................................................................................................... 45
3.9. THE WIRING EDITOR .................................................................................................................. 45
4. Chapter 4 Control .......................................................................................................... 46
4.1. ABOUT THIS SECTION ................................................................................................................ 46
4.2. LOOP VIEW .................................................................................................................................. 46
4.2.1. Loop Overview Parameters ..................................................................................................................... 47
4.3. LOOP CONFIGURATION ............................................................................................................ 48
4.3.1. Key Configuration Parameters. ............................................................................................................... 48
4.3.2. Other Loop Configuration Parameters .................................................................................................. 49
4.4. PID CONTROL .............................................................................................................................. 50
4.4.1. Proportional Term .................................................................................................................................... 50
4.4.2. Integral Term ............................................................................................................................................ 50
4.4.3. Derivative Term ........................................................................................................................................ 50
4.4.4. High and Low Cutback ............................................................................................................................ 51
4.4.5. PID Block Diagram ................................................................................................................................... 51
4.4.6. PID Parameters ......................................................................................................................................... 52
4.5. GAIN SCHEDULING .................................................................................................................... 54
4.5.1. Gain Scheduling Parameters - PID Sets ................................................................................................. 54
4.6. LOOP SETPOINT ......................................................................................................................... 56
4.6.1. Setpoint Parameters ................................................................................................................................ 56
4.6.2. Rate Limit and Holdback Parameters ..................................................................................................... 57
4.6.3. Remote Setpoint Parameters .................................................................................................................. 58
4.6.4. Control Setpoint – Ramp Parameters ..................................................................................................... 58
4.7. LOOP SETPOINT CONFIGURATION ........................................................................................ 59
4.7.1. Setpoint Function Block .......................................................................................................................... 59
4.7.2. Setpoint Configuration Parameters ........................................................................................................ 60
4.8. CONTROL OUTPUT ..................................................................................................................... 61
4.8.1. Output Function Block ............................................................................................................................ 61
4.8.2. Output Parameters .................................................................................................................................. 61
4.8.3. Valve Control Outputs ............................................................................................................................. 63
4.8.4. Valve Control Parameters ........................................................................................................................ 63
4.9. RATIO CONTROL ........................................................................................................................ 64
4.9.1. Basic Ratio Control ................................................................................................................................... 64
Page 5
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 3
4.9.2. Ratio Parameters ...................................................................................................................................... 64
4.10. CASCADE .................................................................................................................................. 66
4.10.1. Overview .................................................................................................................................................. 66
4.10.2. Trim Mode ................................................................................................................................................ 66
4.10.3. Auto/Manual Operation in Cascade ...................................................................................................... 66
4.10.4. Cascade Controller Block Diagram ....................................................................................................... 66
4.10.5. Cascade Parameters ............................................................................................................................... 67
4.11. OVERRIDE ................................................................................................................................. 69
4.11.1. Override Parameters ............................................................................................................................... 70
4.12. TUNING ..................................................................................................................................... 71
4.13. AUTOMATIC (ONE-SHOT) TUNING ...................................................................................... 71
4.13.1. Autotune Parameters .............................................................................................................................. 71
4.13.2. Cascade Tuning ....................................................................................................................................... 73
4.13.3. Example: To Tune a Full Scale Cascade Loop ..................................................................................... 73
4.14. LOOP DIAGNOSTICS .............................................................................................................. 75
4.14.1. Loop Status Word .................................................................................................................................... 75
4.15. LOOP ALARMS ......................................................................................................................... 75
5. Chapter 5 Alarms ......................................................................................................... 76
5.1. DEFINITION OF ALARMS AND EVENTS .................................................................................. 76
5.2. TYPES OF ANALOGUE ALARM USED IN THE 2500 ............................................................... 76
5.2.1. Absolute High .......................................................................................................................................... 76
5.2.2. Absolute Low ........................................................................................................................................... 76
5.2.3. Deviation High Alarm .............................................................................................................................. 77
5.2.4. Deviation Low Alarm ............................................................................................................................... 77
5.2.5. Deviation Band ........................................................................................................................................ 77
5.2.6. Rate Of Change Alarm ............................................................................................................................ 78
5.3. TYPES OF DIGITAL ALARM USED IN THE 2500 ...................................................................... 79
5.4. BLOCKING ALARMS .................................................................................................................... 79
5.4.1. Absolute Low With Blocking .................................................................................................................. 79
5.4.2. Absolute High Alarm With Blocking ...................................................................................................... 79
5.4.3. Deviation Band With Blocking ................................................................................................................ 80
5.5. LATCHING ALARMS .................................................................................................................... 80
5.5.1. Latched Alarm (Absolute High) With Automatic Reset ........................................................................ 80
5.5.2. Latched Alarm (Absolute High) With Manual Reset ............................................................................. 81
5.6. GROUPS & ALARM STATUS WORD .......................................................................................... 81
5.7. LOOP ALARMS ............................................................................................................................. 81
5.7.1. Alarm Parameters .................................................................................................................................... 82
5.8. USER ALARMS .............................................................................................................................. 83
5.8.1. User Alarm Parameters – Analogue ....................................................................................................... 83
5.8.2. User Alarm Parameters – Digital ............................................................................................................. 83
5.9. I/O ALARMS .................................................................................................................................. 84
5.9.1. I/O Alarm Parameters.............................................................................................................................. 84
5.9.2. Analogue Modules .................................................................................................................................. 84
5.9.3. Digital Modules ....................................................................................................................................... 84
5.10. INSTRUMENT STATUS ALARMS ............................................................................................ 85
5.10.1. Individual Channel Status ....................................................................................................................... 85
5.10.2. Status of All Channels in a Module ........................................................................................................ 85
5.10.3. Status of All Channels in a System (IOC) ............................................................................................... 86
5.10.4. Module Status .......................................................................................................................................... 86
5.10.5. System (IOC) Status ................................................................................................................................. 86
Page 6
2500 Controller Engineering Handbook
4 Part No HA027115 Issue 4.0 Mar -11
6. Chapter 6 Operator ..................................................................................................... 87
6.1. LINEARISATION TABLES ............................................................................................................ 87
6.2. DIGITAL COMMUNICATIONS ................................................................................................... 87
6.2.1. Digital Communications Parameters...................................................................................................... 88
6.3. SYSTEM ......................................................................................................................................... 91
6.3.1. System Parameters .................................................................................................................................. 91
6.4. PASSWORD ENTRY ..................................................................................................................... 95
6.4.1. Password Entry Parameters ..................................................................................................................... 95
6.5. PASSWORD SET UP .................................................................................................................... 95
6.5.1. Password Set Up Parameters .................................................................................................................. 95
6.6. DIAGNOSTICS ............................................................................................................................. 95
6.6.1. Diagnostic Parameters ............................................................................................................................ 95
6.7. SYSTEM DESCRIPTIONS ............................................................................................................ 96
7. Chapter 7 I/O MODULES............................................................................................ 97
7.1. OVERVIEW ................................................................................................................................... 97
7.2. I/O BLOCKS .................................................................................................................................. 97
7.3. I/O MODULE INDICATOR LEDS ................................................................................................ 98
7.4. CHANNEL ISOLATION ................................................................................................................ 99
7.5. CHANNEL STATUS AND ERRORS ........................................................................................... 100
7.6. IO MODULE CONFIGURATION CONCEPTS ......................................................................... 101
7.6.1. Module Block Parameters ..................................................................................................................... 101
7.6.2. Module Channel Parameters ................................................................................................................ 104
7.7. ANALOGUE INPUT MODULES ................................................................................................ 105
7.7.1. AI2 Isolation Barriers .............................................................................................................................. 105
7.7.2. AI2 Analogue Input Equivalent Circuits ............................................................................................... 105
7.7.3. AI2 Terminal Connections ..................................................................................................................... 107
7.7.4. AI3 Isolation Barriers .............................................................................................................................. 108
7.7.5. AI3 mA Input Equivalent Circuit ........................................................................................................... 108
7.7.6. AI3 Terminal Connections ..................................................................................................................... 108
7.7.7. AI3 Analogue Input Module Hart Compatibility ................................................................................. 108
7.7.8. AI4 Isolation Barriers .............................................................................................................................. 109
7.7.9. AI4 Analogue Input Equivalent Circuits ............................................................................................... 109
7.7.10. AI4 Terminal Connections ..................................................................................................................... 110
7.7.11. Analogue Input Parameters .................................................................................................................. 110
7.8. ANALOGUE OUTPUT MODULE .............................................................................................. 114
7.8.1. Analogue Output Isolation Barriers...................................................................................................... 114
7.8.2. Analogue Output Equivalent Circuits .................................................................................................. 114
7.8.3. AO Terminal Connections ..................................................................................................................... 114
7.8.4. Analogue Output Channel Parameters................................................................................................ 115
7.9. DIGITAL INPUT MODULES ....................................................................................................... 117
7.9.1. DI4 ........................................................................................................................................................... 117
7.9.2. DI4 Channel Isolation Barriers .............................................................................................................. 117
7.9.3. DI4 Digital Input Equivalent Circuits .................................................................................................... 117
7.9.4. DI4 Terminal Connections..................................................................................................................... 117
7.9.5. DI6 115V and 230V ................................................................................................................................ 118
7.9.6. DI6 Isolation Barriers ............................................................................................................................. 118
7.9.7. DI8 Logic ................................................................................................................................................. 119
7.9.8. DI8 Logic Input Isolation Barriers ......................................................................................................... 119
7.9.9. DI8 Equivalent Circuits .......................................................................................................................... 119
7.9.10. DI8 Terminal Connections..................................................................................................................... 119
7.9.11. DI8 Contact Input ................................................................................................................................... 120
7.9.12. Digital Input Parameters ........................................................................................................................ 120
7.10. DIGITAL OUTPUT MODULES ............................................................................................... 122
7.10.1. DO4 EP (External Power) ....................................................................................................................... 122
7.10.2. DO4 EP Channel Isolation: .................................................................................................................... 122
Page 7
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 5
7.10.3. Digital Output Equivalent Circuits ....................................................................................................... 122
7.10.4. DO4 Terminal Connections: ................................................................................................................. 122
7.10.5. DO4 24V ................................................................................................................................................. 122
7.10.6. Relay Module RLY4 ................................................................................................................................ 123
7.10.7. RLY4 Isolation Barriers .......................................................................................................................... 123
7.10.8. RLY4 Terminal Connections ................................................................................................................. 123
7.10.9. RLY4 Snubber Circuits .......................................................................................................................... 123
7.10.10. Digital Output Channel Parameters ................................................................................................ 124
7.11. CONFIGURATION EXAMPLES ............................................................................................ 126
7.11.1. Thermocouple or RTD Input ................................................................................................................. 126
7.11.2. Pyrometer Input ..................................................................................................................................... 126
7.11.3. Analogue Input: mV, mA, V, ohms ....................................................................................................... 127
7.11.4. Analogue Output................................................................................................................................... 128
7.11.5. Digital Input ........................................................................................................................................... 129
7.11.6. Digital Outputs ...................................................................................................................................... 130
7.11.7. Valve Position Controller ...................................................................................................................... 131
7.11.8. To Calibrate a Potentiometer Input ..................................................................................................... 132
8. Chapter 8 Toolkit Blocks .......................................................................................... 133
8.1. OVERVIEW ................................................................................................................................. 133
8.2. ANALOGUE BLOCKS ............................................................................................................... 133
8.2.1. Analogue Operators ............................................................................................................................. 134
8.2.2. Analogue Block Parameters ................................................................................................................. 135
8.3. DIGITAL BLOCKS ...................................................................................................................... 137
8.3.1. Logic Operators ..................................................................................................................................... 137
8.3.2. Parameters for Digital Blocks ............................................................................................................... 137
8.3.3. Example – To Produce a Logic Calculation Block ............................................................................... 139
8.4. USER VALUES ............................................................................................................................ 140
8.5. TIMER BLOCKS ......................................................................................................................... 141
8.6. TIMER TYPES ............................................................................................................................. 141
8.6.1. On Pulse Timer Mode (PULSE) ............................................................................................................. 141
8.6.2. Off Delay Timer Mode (DELAY) ........................................................................................................... 142
8.6.3. One Shot Timer Mode (1 SHOT) .......................................................................................................... 143
8.6.4. Minimum On Timer Mode (CMPRSS) .................................................................................................. 144
8.6.5. Timer Parameters .................................................................................................................................. 145
8.7. COUNTERS ................................................................................................................................ 146
8.7.1. Counter Parameters .............................................................................................................................. 146
8.8. TOTALISERS............................................................................................................................... 148
8.8.1. Totaliser Parameters .............................................................................................................................. 148
8.9. WIRING....................................................................................................................................... 150
8.9.1. An Example of Soft Wiring .................................................................................................................... 150
8.10. POINT TO POINT WIRING ................................................................................................... 151
8.10.1. WIRES Parameters ................................................................................................................................. 151
8.11. RELATIVE HUMIDITY ............................................................................................................ 152
8.11.1. Overview ................................................................................................................................................ 152
8.11.2. Humidity Parameters ............................................................................................................................. 152
8.12. ZIRCONIA - CARBON POTENTIAL CONTROL .................................................................. 153
8.12.1. Overview ................................................................................................................................................ 153
8.12.2. Zirconia Probe Parameters ................................................................................................................... 153
8.12.3. Temperature Control ............................................................................................................................ 155
8.12.4. Carbon Potential Control ...................................................................................................................... 155
8.12.5. Endothermic Gas Correction ................................................................................................................ 155
8.12.6. Sooting Alarm ........................................................................................................................................ 155
8.12.7. Automatic Probe Cleaning ................................................................................................................... 156
8.13. ORDER IN WHICH CALCULATIONS ARE PERFORMED .................................................. 156
Page 8
2500 Controller Engineering Handbook
6 Part No HA027115 Issue 4.0 Mar -11
9. Chapter 9 Modbus Communications ..................................................................... 157
9.1. OVERVIEW ................................................................................................................................. 157
9.2. MODBUS ADDRESSES.............................................................................................................. 157
9.2.1. Offset ....................................................................................................................................................... 157
9.2.2. Parameter Addresses ............................................................................................................................ 157
9.2.3. Parameter Resolution ............................................................................................................................ 157
9.2.4. Floating Point ......................................................................................................................................... 157
9.3. COMMUNICATIONS BLOCKS ................................................................................................. 158
9.3.1. Block Communications .......................................................................................................................... 158
9.3.2. Indirection Tables .................................................................................................................................. 158
9.3.3. Read Write Source Indirection Table ................................................................................................... 158
9.3.4. Read Write Value Indirection Table ...................................................................................................... 158
9.3.5. Read Only Indirection Table ................................................................................................................. 158
10. Chapter 10 Profibus Communications .................................................................. 159
10.1. OVERVIEW ............................................................................................................................. 159
10.2. PROFIBUS INSTALLATION ................................................................................................... 159
10.3. CONFIGURATION OF THE 2500 FOR PROFIBUS ............................................................ 159
10.4. A 'GSD' FILE ........................................................................................................................... 159
10.5. TO CREATE A NEW GSD FILE ............................................................................................. 160
10.6. TO SAVE THE GSD FILE ........................................................................................................ 161
10.7. OPERATING AND APPLICATION NOTES .......................................................................... 162
11. Chapter 11 Devicenet Communications ................................................................ 163
11.1. OVERVIEW ............................................................................................................................. 163
11.2. DEFAULT MAPPING .............................................................................................................. 163
11.3. 2500 DEFAULT PARAMETER MAPPING ............................................................................ 163
11.4. CUSTOM PARAMETER MAPPING ....................................................................................... 164
11.4.1. Indirection Tables .................................................................................................................................. 164
11.4.2. Read Write Indirection Table ................................................................................................................ 164
11.4.3. Read Only Indirection Table ................................................................................................................. 164
12. Chapter 12 Ethernet Communications .................................................................. 165
12.1. OVERVIEW ............................................................................................................................. 165
12.1.1. Support for other Ethernet utilities ....................................................................................................... 165
12.2. CONFIGURATION OF THE 2500 FOR ETHERNET ........................................................... 166
12.2.1. General ................................................................................................................................................... 166
12.2.2. Setting the Instrument Address ............................................................................................................ 166
12.2.3. DIP Switches ........................................................................................................................................... 166
12.3. ETHERNET COMMUNICATIONS PARAMETERS ............................................................... 167
12.3.1. Unit Ident Enable ................................................................................................................................... 167
12.3.2. IP Address ............................................................................................................................................... 167
12.3.3. Subnet Mask ........................................................................................................................................... 168
12.3.4. Default Gateway ..................................................................................................................................... 168
12.3.5. Preferred Master - Multiple Connections............................................................................................. 168
12.3.6. MAC Address ......................................................................................................................................... 169
12.3.7. Dynamic Host Configuration Protocol ................................................................................................. 169
12.4. MODBUS EXCEPTIONS ........................................................................................................ 170
12.5. COMMUNICATIONS INDICATORS ..................................................................................... 170
12.5.1. Modbus communications indicator...................................................................................................... 170
12.5.2. Ethernet communications indicators.................................................................................................... 170
12.6. NETWORK WATCHDOG ...................................................................................................... 170
Page 9
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 7
13. Chapter 13 Calibration ............................................................................................ 171
13.1. OVERVIEW ............................................................................................................................. 171
13.2. SIMPLE OFFSET .................................................................................................................... 171
13.2.1. To Perform Offset Calibration .............................................................................................................. 172
13.3. USER CALIBRATION ............................................................................................................. 172
13.3.1. To Perform User Calibration ................................................................................................................. 173
13.4. REFERENCE CALIBRATION ................................................................................................. 174
13.4.1. Analogue Input Calibration Procedure ............................................................................................... 175
13.4.2. Analogue Output Calibration Procedure ............................................................................................ 176
13.4.3. Restore Factory Calibration .................................................................................................................. 176
14. Appendix A SPECIFICATION ..................................................................................... 177
15. Appendix B The Ordering Codes ............................................................................ 185
16. Appendix C To Remove Snubber Circuits From The Relay Module................... 192
17. Appendix D Glossary of Terms ................................................................................ 194
18. Index .............................................................................................................................. 195
19. Index - Key Words ....................................................................................................... 219
ISSUE STATUS OF THIS MANUAL
Issue 3.0 contains the following changes:Contents updated to include 2500 IOC note below
Chapter 2 updated to include Modbus and Profibus links
Chapter12 updated to include the parameter Unit ID Enable
Index added
2500 IOC – Version 3.7 and Version 4.3 (SYSIO) Software Upgrade Notification.
The above software versions introduce additional fault action and sensor break detection parameters for
Analogue Inputs.
Existing Users
Caution should be exhibited when loading existing applications.
Carefully check Fault actions responses.
Issue 4.0 moves Safety and EMC Information to the beginning of the manual. Module specifications updated
and moved to Appendix A . Re-format to A4 size.
Page 10
2500 Controller Engineering Handbook
8 Part No HA027115 Issue 4.0 Mar -11
SAFETY and EMC INFORMATION
Please read this section carefully before installation
This controller is manufactured in the UK by Eurotherm Ltd.
It is intended for industrial temperature and process control applications when it will meet the requirements of
the European Directives on Safety and EMC. Use in other applications, or failure to observe the installation
instructions of this handbook may impair the safety or EMC protection provided by the controller. It is the
responsibility of the installer to ensure the safety and EMC of any particular installation.
Safety
This controller complies with the European Low Voltage Directive 2006/95/EC, by the application of the safety
standard EN 61010.
Electromagnetic compatibility
This controller conforms with the essential protection requirements of the EMC Directive 2004/108/EC, by the
application of a Technical Construction File.
This instrument satisfies the general requirements of an industrial environment as described by EN 50081-2 and
EN 50082-2. For more information on product compliance refer to the Technical Construction File.
Service and repair
This controller has no user serviceable parts. Contact your nearest Eurotherm Controls agent for repair.
Some module terminal units may contain fuses and must be replaced by the correct type of fuse. These are T
type rated at 2 Amps to EN60127.
Electrostatic discharge precautions
When a module is removed from the base, any exposed electronic components are vulnerable to damage by
electrostatic discharge from someone handling it . To avoid this, before handling the unplugged module
discharge yourself to ground.
If removing a PCB from its sleeve, for example - to remove snubbers from the Relay Module, please use antistatic precautions.
Cleaning
Do not use water or water based products to clean labels or they will become illegible. Isopropyl alcohol may
be used to clean labels. A mild soap solution may be used to clean other exterior surfaces of the product.
Page 11
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 9
Installation Safety Requirements
Safety Symbols
Various symbols are used on the instrument, they have the following meaning:
Caution, (refer to the
accompanying documents)
Functional earth
(ground) terminal
!
Personnel
Installation must only be carried out by qualified personnel.
Enclosure of live parts
To prevent hands or metal tools touching parts that may be electrically live, the controller must be installed in an
enclosure.
Blank Terminal Unit
Bases are supplied to hold 4, 8 or 16 modules. In the event that a base is not fully populated a blank terminal
unit, part number 026373, will be supplied with the system. It is important that this is fitted into the position
immediately to the right of the last module in order to maintain IP20 rating. See Chapter 3 ‘Terminal Units’ for
installation details.
Caution:
Live sensors
The controller is designed to operate with the temperature sensor connected directly to an electrical heating
element . However you must ensure that service personnel do not touch connections to these inputs while they
are live. With a live sensor, all cables, connectors and switches for connecting the sensor must be mains rated.
Wiring
It is important to connect the controller in accordance with the wiring data given in this handbook. Take
particular care not to connect AC supplies to the low voltage sensor input or other low level inputs and outputs.
Only use copper conductors for connections (except thermocouple inputs) and ensure that the wiring of
installations comply with all local wiring regulations. For example in the UK use the latest version of the IEE
wiring regulations, (BS7671). In the USA use NEC Class 1 wiring methods.
Power Isolation
The installation must include a power isolating switch or circuit breaker. This device should be in close
proximity to the controller, within easy reach of the operator and marked as the disconnecting device for the
instrument.
Earth leakage current
Due to RFI Filtering there may be an earth leakage current of up to 3.5mA. This may affect the design of an
installation of multiple controllers protected by Residual Current Device, (RCD) or Ground Fault Detector, (GFD)
type circuit breakers.
Overcurrent protection
It is recommended that the DC power supply to the system is fused appropriately to protect the cabling to the
units. The 2500 provides a fuse on the IOC Terminal Unit to protect the supply from a fault within the 2500.
Voltage rating
The maximum continuous voltage applied between any of the following terminals must not exceed 264Vac:
• relay output to logic, dc or sensor connections;
• any connection to ground.
The controller should not be wired to a three phase supply with an unearthed star connection. Under fault
conditions such a supply could rise above 264Vac with respect to ground and the product would not be safe.
Voltage transients across the power supply connections, and between the power supply and ground, must not
exceed 2.5kV. Where occasional voltage transients over 2.5kV are expected or measured, the power
installation to both the instrument supply and load circuits should include a transient limiting device.
These units will typically include gas discharge tubes and metal oxide varistors that limit and control voltage
transients on the supply line due to lightning strikes or inductive load switching. Devices are available in a
range of energy ratings and should be selected to suit conditions at the installation.
Protective earth
terminal
Page 12
2500 Controller Engineering Handbook
10 Part No HA027115 Issue 4.0 Mar -11
Conductive pollution
Electrically conductive pollution must be excluded from the cabinet in which the controller is mounted. For
example, carbon dust is a form of electrically conductive pollution. To secure a suitable atmosphere in
conditions of conductive pollution, fit an air filter to the air intake of the cabinet. Where condensation is likely,
for example at low temperatures, include a thermostatically controlled heater in the cabinet.
Over-temperature protection
When designing any control system it is essential to consider what will happen if any part of the system should
fail. In temperature control applications the primary danger is that the heating will remain constantly on. Apart
from spoiling the product, this could damage any process machinery being controlled, or even cause a fire.
Reasons why the heating might remain constantly on include:
• the temperature sensor becoming detached from the process;
• thermocouple wiring becoming short circuit;
• the controller failing with its heating output constantly on;
• an external valve or contactor sticking in the heating condition;
• the controller setpoint set too high.
Where damage or injury is possible, we recommend fitting a separate over-temperature protection unit, with an
independent temperature sensor, which will isolate the heating circuit.
Please note that the alarm relays within the controller will not give protection under all failure conditions.
Grounding of the temperature sensor shield
In some installations it is common practice to replace the temperature sensor while the controller is still
powered up. Under these conditions, as additional protection against electric shock, we recommend that the
shield of the temperature sensor is grounded. Do not rely on grounding through the framework of the
machine.
Installation requirements for EMC
To ensure compliance with the European EMC directive certain installation precautions are necessary as follows:
• For general guidance refer to Eurotherm Controls EMC Installation Guide, HA025464.
• When using relay outputs it may be necessary to fit a filter suitable for suppressing the emissions. The filter
requirements will depend on the type of load. For typical applications we recommend Schaffner FN321 or
FN612.
Routing of wires
To minimise the pick-up of electrical noise, the wiring for low voltage dc and particularly the sensor input should
be routed away from high-current power cables. Where it is impractical to do this, use shielded cables with the
shield grounded at both ends.
Functional Insulation
This is defined as: Insulation between conductive parts that is necessary only for the proper functioning of the
equipment. This does not necessarily provide protection against electric shock.
Reinforced Insulation
This is defined as: Insulation between conductive parts which provides protection against electric shock.
Additional EMC Protection on Profibus IOC
In environments where excessive noise levels are likely, it is recommended that a ferrite clamp is fitted around
the Profibus cable. This has the effect of increasing the noise immunity from 2KV to 3.7KV.
A suitable ferrite clamp is Richo type MSFC -5T.
Page 13
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 11
1. Chapter 1 INTRODUCTION
Thank you for selecting the 2500 DIN Rail Controller and Data Acquisition Unit. This chapter provides an
overview of your controller.
1.1. ABOUT THIS HANDBOOK
This handbook is intended for those who wish to configure and use the 2500 DIN Rail Controller and Data
Acquisition Unit.
It may be used in conjunction with the following related handbooks:
Subject Handbook Name Part Number
Installation and hardware
details of the 2500 DIN Rail
Controller
2500 Installation and Wiring
Handbook.
(Supplied with the instrument)
HA026178
Description of configuration
tool for 2000 series instruments
iTools User Handbook.
(Supplied with iTools software)
HA026179
EMC and Wiring Practice EMC Installation Guide HA025464
Serial Communcations 2000 Communications Handbook HA026230
In general chapters are presented in the order in which these ‘folders’ appear in iTools.
Chapter 1 provides an overview of the 2500 Unit.
Chapter 2 describes Modbus, Profibus, Devicenet and Ethernet versions of the Input Output Controller (IOC)
modules.
Chapter 3 describes how the 2500 is configured using “iTools”. iTools is a software package running on a
personal computer under Windows 95, 98, 2000, ME, XP or NT(service pack 4 or later). It provides a ‘view’ into
the controller and allows configuration, commissioning and if necessary operation. The general features of the
iTools package are described in more detail in the User Handbook HA026179. As iTools is an essential partner
for the 2500, this engineering manual makes frequent references to it.
The remaining chapters provide more information about all the functions available in the 2500, including details
about how to configure each function, what the parameters mean and typical applications.
Appendix D is a Glossary of terms used in this manual
1.2. SYMBOLS USED IN THIS MANUAL
Symbol Meaning
(xx) Numbers in ( ) are the enumerated values for a parameter
Read only
Write only
¦9 Range set between high and low limits in engineering units
¦% Range set between high and low limits in %
Time units days, hours, minutes, seconds, ms
☺
Hint or useful information
1.2.1. File Paths
Parameters are located in lists. Each list is associated with a particular subject such as Alarms, Control, etc.
The following example shows how a parameter is located in a file path:
Control → LOOP01 → L01CFG → Ctrl
Where ‘Ctrl’ is the parameter (Control Type) found in the path ‘Control’ ‘Loop number 1’ ‘Loop number 1
configuration list’.
Page 14
2500 Controller Engineering Handbook
12 Part No HA027115 Issue 4.0 Mar -11
1.3. STATUS WORDS
Status Words group together commonly accessed parameters in convenient categories so that they may be
read as a single transaction. An example may be alarm states as shown in section 5.10. The ‘Global Alarm
Status Word’ from Table 5-7 is reproduced below. This is a bit map of 16 bits and the value shown in each table
in this manual is a decimal number. For example if the value is 31 then the first four bits are set.
The example below shows how this may be calculated:In Hexadecimal 31 = 1F
1F
=
0001
1111
Bits set
7654
3210
Bit area
This shows that bits 0 to 4 are set
Bit Value
(Decimal)
Set when:
0 1 Any channel - Sensor break detected
1 2 Any channel - CJC failed
2 4 Any channel - Channel not in use
3 8 Any channel - Analogue output saturated
4 16 Any channel - Initialising
5 32 Any channel - Invalid Analogue Cal data
6 64 Reserved for future use
7 128 Any channel - Module fault
8 256 Any Module is missing
9 512 Any Wrong Module fitted
10 1024 Any Unrecognised Module fitted
11 2048 Any Module Comms Error
12 4096 Reserved for future use
13 8192 Reserved for future use
14 16384 Reserved for future use
15 32768 Reserved for future use
Table 1-1: Global IO Status Word and Bit Field
Value
(Hex)
Bit Field
0 0000
1 0001
2 0010
3 0011
4 0100
5 0101
6 0110
7 0111
8 1000
9 1001
A 1010
B 1011
C 1100
D 1101
E 1110
F 1111
Page 15
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 13
1.4. WHAT IS THE 2500?
The 2500 is a modular system which can provide multi-loop PID control, analogue and digital I/O, signal
conditioning and computational blocks with a variety of plug-in modules.
Figure 1-1: General View of the 2500 DIN Rail Controller and I/O Unit
The base unit (2500B) can be provided in different sizes, with up to 16 I/O modules. The base can be mounted
on DIN rail (35mm top-hat), or just bolted to a wall.
Terminal Units (2500T) clip into the base, providing customer connections to and from the plant devices and
interconnections between modules and the Input Output Control module (IOC). Terminal units are specific to
particular modules as defined in the order code, Appendix B.
I/O Modules (2500M) clip into the Terminal Units. These modules are dedicated to specific functions - analogue
or digital, input or output. The IOC module (2500E or 2500C) contains the configuration for the system and
communications support. Three communications versions are available for Modbus, Profibus or Devicenet.
The system requires 24Vd.c. at an average of 100mA per module. A suitable power supply is 2500P available in
2.5, 5 or 10 amp versions.
1.5. WHAT DOES THE 2500 DO?
The 2500 system functions around a database core. In this database all important system numbers and values
are stored as parameters at specific addresses. Examples are measured voltages, PVs, status words, channel
settings, limits, PID loop values.
This database is updated regularly every 110ms (nominal). At each update input channel values are recorded
and output channel signals are set. All computational blocks - PID loops, Toolkit blocks, user wiring and so on
are also calculated and updated on each 110ms tick.
Network communications is implemented as a gateway to the database. Any network transaction driven by an
external master effectively reads and writes to database parameters. The only difference is that the network
updates are asynchronous - the transaction rate is set by the master.
There are two key aspects to the use of the 2500:-
1. the set-up or configuration of the system to implement the desired control strategy;
2. the run-time execution of that strategy.
This handbook concentrates on configuration aspects as being a convenient way to explore the considerable
number of features available in the 2500 system.
Digital
communications
ports RS485/422
Address switch
Configuration
port RS232
2500B Base
Plant and Process
Connections
O
p
tional Fuses
or Isolator links
I/O Control Module (IOC)
Always mounted in the left hand position.
This view shows the Modbus IOC
2500M Plug-in I/O Modules
Can be mounted in any order
Page 16
2500 Controller Engineering Handbook
14 Part No HA027115 Issue 4.0 Mar -11
1.6. THE COMPONENTS OF THE 2500
The 2500 is normally supplied as a number of separate parts, identified by a unique model code printed on
labels on the packaging and on each item. These codes are explained in Appendix B.
The parts can be briefly classified as follows:
the Base - “2500B”
the I/O Controller Module - “2500E” (or the superseded “2500C”)
the I/O Modules - “2500M”
the Terminal Units - “2500T”
the 24V Power Supply - “2500P” mounted separately from the 2500 base
Accessories - “2500A” (e.g. cables and terminators)
The electrical interconnection of these parts is shown in the block diagram below. The Base unit contains a PCB
linking the modules together - the I/O Bus.
Figure 1-2: 2500 Block Diagram
1.7. UNPACKING THE INSTRUMENT
The instrument is despatched in a special pack, designed to give adequate protection during transit. Should
the outer box show signs of damage, it should be opened immediately, and the contents examined. If there is
evidence of damage, the instrument should not be operated and the local representative contacted for
instructions. After the instrument has been removed from its packing, the packing should be examined to
ensure that all accessories and documentation have been removed. The packing should then be stored against
future transport requirements.
Terminal unit
2500T
IOC
module
2500C or
2500E
I/O
module 1
2500M
I/O
module 2
2500M
I/O
module 3
2500M
I/O
module n
2500M
Plant or Machine under control
Internal I/O bus
Terminal unit
2500T
Terminal unit
2500T
Terminal unit
2500T
Terminal unit
2500T
Modbus or Profibus
or Devicenet
communications to
host PC or Display
Unit
→
→
Page 17
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 15
1.8. MECHANICAL INSTALLATION
The 2500 base unit is intended to be mounted in an enclosure, or in an environment suitable for IP20 rated
equipment. It can be DIN or bulkhead mounted. When mounted on DIN rail it is locked with the clamps at each
end. The unit can be mounted in any orientation, but it is normal to refer to the I/O Bus PCB as the top, as in
Figure 1-3 below.
Figure 1-3: The 2500 Base and Terminal Units
Warning
The equipment should not be operated without a protective earth conductor connected to one of the
earth terminals on the base unit. The earth cable should have at least the current rating of the largest
power cable used to connect the instrument. The protective earth cable should be terminated with a
suitable tinned copper eyelet, retained by one of the screw and washer supplied with the base unit,
tightened to a torque of 1.2Nm (10.5lbin). This connection also provides a ground for EMC purposes.
Dimension B
2 module 46 mm
4 module 96 mm
8 module: 200 mm
10 module: 249 mm
12 module 300 mm
16 module 402 mm
I/O Bus PCB
Location
tabs
Safety Earth
connection
(two places)
DIN rail fixing clips
DIN rail
fixing clips
DIN rail
B
180mm
Page 18
2500 Controller Engineering Handbook
16 Part No HA027115 Issue 4.0 Mar -11
1.8.1. DIN Rail Mounting
For DIN rail mounting, symmetrical, horizontally-mounted 35x7.5 or 35x15 DIN rail to BS EN50022 should be
used.
1. Mount the DIN rail, using suitable bolts, ensuring that it makes good electrical contact with the
enclosure metal work either via the bolts or by means of a suitable earthing cable.
2. Loosen the screws (‘A’ in Figure 1-3) in the base unit, two or three turns, and allow them, and the
associated fixing clips to slide to the bottom of the screw slot.
3. Lower the base unit onto the DIN rail such that the top edge of the rail fits into the slot on the underside
of the support bar (see Figure 1-3)
4. Slide the screws ‘A’ and associated clips as far as they will go towards the top of the screw slots,
ensuring that the top of each fixing clip locates behind the bottom edge of the DIN rail.
5. Tighten the screws, and check that the base unit is fully secure on the rail.
1.8.2. Panel Mounting
Warning
Bolts heads must not exceed 5mm in height, or there will be insufficient isolation clearance between
the bolt head and the relevant terminal unit(s).
1. Remove the screws (‘A’ in Figure 1-3) and associated fixing clips.
2. Holding the base unit horizontally on the panel, mark the position of the two holes on the panel
3. Drill two suitable holes in the panel and use two suitable bolts (M5 recommended) to secure the base
unit to the panel, ensuring that good electrical contact with the enclosure metal work is made either via
the bolts or by means of a suitable earthing cable.
1.8.3. Terminal Unit Installation
1. Isolate the supply power to the instrument
2. Insert the tag at the top of the terminal unit printed circuit board into the relevant slot in the Base Unit
(action ‘B’ in Figure 1-4.)
3. Press on the bottom of the terminal unit until a ‘click’ confirms that the retention clip has sprung back
into position to secure the terminal unit (action ‘C’).
Note: If the Base Unit is not fully populated a blank Terminal Unit (supplied) must be fitted
immediately to the right of the final module position in order to maintain IP20 rating.
1.8.4. Terminal Unit Removal
1. Remove any module fitted on the terminal unit (section 1.8.6 below)
4. If necessary remove all wiring from the terminal unit
5. Press the retention clip at the bottom of the terminal unit and lift the terminal unit out (action ‘D’).
Figure 1-4: Terminal Unit installation/removal
Page 19
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 17
1.8.5. To Fit a Module
Note: Polarising keys prevent modules from being fitted to unsuitable terminal units.
1. Pull the module retaining lever forwards into the unlocked position as shown in Figure 1-5.
2. Offer the module up to the terminal unit and the backplane, and push home.
3. Return the retaining lever to the locked position.
1.8.6. Module Removal
1. Pull the module retaining lever forwards into the unlocked position as shown in Figure 1-5.
2. Disengage the module from the backplane connector and lift the module out of the base unit.
Figure 1-5: I/O Module (Side View)
Page 20
2500 Controller Engineering Handbook
18 Part No HA027115 Issue 4.0 Mar -11
1.9. I/O MODULE FUNCTIONS
The 2500 system provides I/O modules designed to accept wiring directly from common control plant
transducers , such as thermocouples, transmitters, valve positioners. The I/O modules provide the basic
hardware interface. Software features adapt this interface for different ranges or functions, and add signal
processing capability. The following is a summary of the hardware interface capability:-
Analogue input
modules
provide:-
• 150mVd.c. range at high impedance
• 10Vd.c. range through a medium impedance attenuator
• 2V high-impedance range is provided for Zirconia probe applications
• 4-20mA range is supported with appropriate terminal units
• Linearised 3-Wire resistance measurement
• Potentiometer input
• Linearised thermocouple measurement. The TC terminal units support a cold
junction temperature sensor for thermocouple applications for automatic CJC
Analogue
output modules
support:-
• 4-20mA
• 0-10Vd.c. ranges, switched by software.
Digital input
modules
accept:-
• Industrial logic levels (24Vd.c.)
• Line supply (115Va.c. or 230Va.c.),
• Switch contact inputs. Debounce and event detect is included.
Digital output
modules
provide:-
• Switched outputs for 24Vd.c. applications at up to 100mA.
• Channels can be configured for time proportioning on/off and valve position
algorithms.
Relay modules
provide:-
• Contacts outputs for power applications to 2A at 240Va.c.
• Channels can be configured as digital output modules
Page 21
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 19
2. Chapter 2 The IOC Module
2.1. OVERVIEW
The Input / Output Controller module (IOC) is the central
processing unit of the 2500 system.
The IOC maintains a database of all system parameters,
updated on a regular tick interval for consistent control
loop behaviour.
Parameters are at fixed published addresses, so any subset
of parameters can be easily accessed through network
communications.
Each parameter has attributes by design - visibility,
alterability and volatility. This last means that critical
information (like the configuration) is preserved even after
power-down.
Figure 2-1: The IOC
All I/O modules are controlled by the IOC as a background task. The IOC:-
• verifies I/O module types fitted against the configuration specified
• initialises and tests modules at start-up and with hot-swap
• sets the hardware to ranges appropriate against the configuration
• sets module electrical outputs or reads inputs on a regular tick
• maintains a set of alarms to track faults and exceptions
Complex strategies can be built up from calculation blocks and tools, operating on the raw input and output
data connected together with user defined software "wires":
• Up to 8 PID control blocks provide instant sophisticated control loops
• "Toolkit Block" functions provide user-wireable software components like timers, totalisers and counters
• Alarms provide limit control and easy exception handling
The IOC supports several communications interfaces for configuration and large networked systems, SCADA
packages, T940 and the Visual Supervisor, PLCs and so on:
• an RS232 interface using an RJ11 connector is used for system configuration
• Modbus 3-wire or 5-wire communications
• Profibus DP or Profibus DPv1 communications
•
DeviceNet
communications
The last three each require a dedicated version of the IOC and Terminal Unit; the "Configuration Port" is
standard on all IOCs.
Page 22
2500 Controller Engineering Handbook
20 Part No HA027115 Issue 4.0 Mar -11
2.2. OPERATING MODES
The IOC offers several operating modes:-
The 'Run' mode provides the normal execution of the I/O and control strategy.
The 'Config' mode unlocks system parameters for configuration or re-configuration, while inhibiting the
output modules.
The 'Standby' mode is a transition mode normally inserted by the IOC when changing from one mode to
another.
The 'Fail' mode is drastic, invoked only if the IOC detects a hardware problem
Note:- The IOC contains an applications specific program - the 'control strategy'. Obviously accidental
change to a strategy could adversely affect the controlled plant, even introducing risk of hazard.
To avoid risk the IOC 'Config' mode forces I/O module outputs to a electrical low levels. While it is
possible to change some parameters in 'Run' mode; any such change must be implemented only with
the utmost caution.
Similarly when changing an IOC there is a risk of accident - for example, the new IOC could have an
inappropriate strategy configured for the specific application. Before changing one IOC for another
ensure that the new module contains the correct strategy.
A ‘Configuration Key’, order code 2500A/CFGKEY, is available which should be plugged into the RJ11
socket before the IOC is powered up (see also section 2.2.3.). With this in place the IOC will start up in
the safer 'Config' mode. This plug must be removed from the IOC after power-up. The IOC will stay in
the 'Config' mode after the plug is removed, and the strategy can be verified in any way appropriate.
The 'Run' mode can then be set by the network master by writing to the Requested Instrument Mode
parameter.
2.2.1. Run Mode
The operating mode or 'Run' mode is the normal machine state. In 'Run' mode the green indicator LED marked
"" is illuminated, the 'C' and 'S' LEDs extinguished..
Control loops, toolkit blocks, wires, alarms, input and output blocks are all executed and the parameters in the
database updated. Appropriate parameters (for example, output channel PVs) can be modified over network
communications.
Parameters associated with the design of the strategy are locked; for example, soft wires cannot be modified;
channel types cannot be changed; calibration values cannot be modified.
Software versions from 3.26 permit limited on-line reconfiguration of many 'Config' parameters to allow finetuning of a strategy design. This does not include critical control loop parameters. This state is protected with a
special parameter for 'Live Configuration', ‘LveCnf’ in the Operator/System list.
Due care should be taken when changing the value of 'LveCnf'; it should NOT be left enabled.
2.2.2. Configuration Mode
'Configuration' or 'Config' mode is intended for control strategy design, set-up and test. For this reason this
mode permits complete alteration of blocks and wires. Configuration is easily performed from iTools from the
'Config' port or the Modbus network communications port. When in 'Config' mode the yellow indicator LED 'C'
is illuminated.
Configuration mode can be entered by:-
powering up with the 'Config' lead connected to a PC
toggling the iTools access level icon
setting the ‘Instrument Mode’ parameter to 2 with iTools
any means over the network communications port
If the IOC has been put into configuration mode it will stay in 'config' even through power-cycle until it is
explicitly set into operating mode.
In 'Config' mode digital outputs are disabled (logic 0 output), analogue outputs drive the level defined by the
electrical low limit (IOL).
!
!
Page 23
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 21
2.2.3. Configuration Key
The configuration key ensures that the IOC powers up in configuration mode. The key is fitted into the
configuration port of the IOC and has the same effect as powering up the IOC with the config lead connected to
a PC, see section 2.2.2.
It is recommended that the key is fitted, for example, when a new or spare IOC with unknown configuration
program is used to replace another IOC in an on line system.
Figure 2-2: Configuration Key Shown Fitted
2.2.4. Standby Mode
The 'Standby' mode is a transition mode normally invoked by the IOC when changing between Run and Config
at start-up. A yellow LED 'S' on the front of the IOC is illuminated in 'Standby' mode.
This mode inhibits changes to parameters and forces output modules to electrical low levels.
This mode would not normally be required by users.
2.2.5. Fail Mode
'Fail' mode is only entered when the IOC detects a hardware fault during normal operation. This state is
consequently rare. The red LED 'X' on the front of the IOC will blink rapidly in the 'Fail' mode.
On software versions V3.30 or V4.00 or higher the user can save the strategy as a clone file; the system can only
be recovered by forcing a cold-start. This is a return-to-factory repair.
Page 24
2500 Controller Engineering Handbook
22 Part No HA027115 Issue 4.0 Mar -11
2.3. CONFIGURATION PORT
The IOC configuration port ('Config' port) is provided on the front face of the IOC. This RJ11 socket supports
EIA232 with a fixed 9600 baud rate, no parity, 8 bit data and 1 stop bit for extremely simple and reliable
connection to a PC. Any PC based software supporting Modbus can thus communicate with the 2500 system including the iTools package. A suitable interconnection cable is available, part
2500A/CABLE/CONFIG/RJ11/(PINDF/3M0.
Pin connections
RJ11 into IOC
Pin connections
9 way D-type to PC
6 (no connection)
5 (RX) 3 (TX)
4 (TX) 2 (RX)
3 (0V) 5 (0V)
2 (no connection)
1 (24V (in))
(Screen) (Screen)
Table 2-1: Connections for IOC to PC Link
Figure 2-3: RJ11 Configuration Pin Identification
When the IOC is powered up with a PC connected to the RJ11 configuration port, it will start in the 'Config'
mode. The port always uses network address 255, overriding any address switch setting. When the 'Config'
lead is in use the Terminal Unit network connections are disabled, whether Profibus, Modbus or DeviceNet.
A plastic cover is supplied which must be fitted when the IOC is in normal operation.
RJ11-6 way
Cable to PC...
Connectors at the
back in this view
1
6
View into socket
6
1
PAC 2500
Modbus
Page 25
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 23
2.4. STATUS INDICATION
Five LED indicators show the status of an IOC module as follows:
LED Colour ON ALL OFF
S
C
Green
Yellow
Yellow
Normal operation
Standby (See Note 1)
Configuration
Self test failed on
power up
&C
both on
As
above
Normal operation with online IO
reconfiguration enabled
Self test failed on
power up
LED Colour ON OFF
Yellow IO network or configuration port
communicating
LED Colour ON (See also Note 1) OFF
X
Red 1. Non-volatile RAM checksum
failure
2. Custom linearisation checksum
failure
3. I/O network watchdog (if
configured)
4. Invalid base size detected
5. Module missing, faulty or wrong
type
Normal operation
Flashing
X
Red Power on self test failed Refer to section 2.5
Figure 2-4: IOC Status Indication
The
DeviceNet
health indicator is not shown; this lights red if the network side is unpowered or non-functional.
Note 1:
1. Non-volatile RAM checksum failure.
Identified by the Non-Volatile Memory Failure Flag in Operator → SYSTEM → NVFail.
2. Custom linearisation checksum failure.
Identified by Custom Linearisation Failure Flag in Operator → SYSTEM → ClinFl.
Either condition 1 or 2 above will cause the red LED to flash and the system to go into fail safe mode.
3. I/O network watchdog.
Identified by Custom I/O Network Watchdog Flag in Operator → SYSTEM → NWdged and indicates that
network communication has not occurred for longer than the watchdog duration. The watchdog may be
configured to recover automatically. This will clear the Nwdged flag when communications are restored.
The flag can be cleared by writing 0 to the IO Network Watchdog Timeout Flag found in Operator →
SYSTEM → IONwdg.
4. Invalid base size detected.
Indicated by any value other than 0, 2, 4, 8, 10, 12 or 16 in the Base Size parameter found in Operator →
SYSTEM → BaseSz. This indicates genuine hardware fault as the IOC does not recognise the hardware
base size code being read from the backplane.
5. Any IO (channel or module) status bit set except the channel not used bit (bit 2 of the channel status).
Indicated by the Global IO Status parameter found in Operator → SYSTEM → Iostat. The Global IO Status is
an OR of all the module status parameters (found in IO → Module xx → MODxx → ModSta) in the most
significant byte, and an OR of all the channel status parameters (found in IO → Modulexx → Mxx_Cy →
ChStat) in the least significant byte.
To clear this fault all modules and channels should be indicating no fault. For analogue inputs this may
require a link on any unused input or configuring them as V to remove any spurious sensor break
indications.
Page 26
2500 Controller Engineering Handbook
24 Part No HA027115 Issue 4.0 Mar -11
2.5. INITIALISATION AND POWER ON SELF TEST
The IOC goes through an initialisation sequence when power is applied, and will start in either 'Run' mode or
'Config' mode. The tests illuminate the indicators in a specific pattern.
LED
Test
Flash ROM RAM
Test
Nvol
Test
Watch-dog Test Nvol
Check-sum
Test
Initial-
isation
Full
Operation (2)
Figure 2-5: LED Indication During Start Up
Power On
ROM
Test Pass
Nvol
Test Pass
LED Test
RAM
Test Pass
Watchdog
Test Pass
Nvol Checksums
Test Pass
(2)
Rom Test
Fail
RAM Test Fail
Nvol Test Fail
Watchdog Test Fail
‘Flashing'
LED On
LED Off
Top LED is ON if the 2500 is in operation level
Centre LED ON if the 2500 is in standby
Lower LED ON if the 2500 is in configuration mode
C
Á
S
Note 1
Note 2
Nvol Checksum failure
Page 27
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 25
2.6. MODBUS IOC AND TERMINAL UNIT
The Modbus IOC is identified by the front label and the order code printed on the side label. This IOC must be
used with the Modbus Terminal Unit.
Figure 2-6: Modbus IOC Module and Terminal Unit
The Modbus network connection and the 2500 system power connections are provided by the Terminal Unit;
the latter with standard screw terminals, the former with RJ45 sockets.
The network connection is used for connection to an operator interface unit, a PC running iTools or 3rd party
system, or to link further slave 2500 controllers or other Modbus equipment in a system.
The IOC can also be configured from the Modbus network if required.
2.6.1. Connections to the RJ45 Sockets
The two RJ45 sockets are parallel connected for network daisy-chaining, with the connections:
RJ45 pin Colour EIA-485 2 wire 4 wire
1 Orange /
White
B D- TX-
2 Orange A D+ TX+
3 Green / White Gnd Gnd Gnd
4 Blue - - 5 Blue / White - - 6 Green Gnd Gnd Gnd
7 Brown / White B - RX8 Brown A - RX+
Screen - - - -
NOTE: Blue and Blue/White Wires are not used.
CABLE COLOURS MAY CHANGE!
Table 2-2: RJ45 Modbus Connections
Plastic covers are supplied which must be fitted when the system is in normal operation.
!
* RS422-485 Modbus communications selection
Fit both links:
1 – 2 for 2 (3) wire Modbus (default)
2 – 3 for 4 (5) wire Modbus (default)
Note: Earlier units were fitted with a single link for
2(3) wire or no link for 4(5) wire.
Fit suitable termination ONLY on the last device in
the chain.
The use of the termination plug is recommended
Address Switch
Di
g
ital Communications
Ports
RS485
24V power supply terminals
Module connector
I/O Module
interconnection bus
RS485/422 Links *
1
2
3
Configuration Port (RS232)
LED Status Indicators
0
V
+24
V
Page 28
2500 Controller Engineering Handbook
26 Part No HA027115 Issue 4.0 Mar -11
2.6.2. The RJ45 Modbus Line Terminator
All network communications lines must be terminated using appropriate impedance. To provide correct resistor
values for CAT-5 cable and to match the RJ45 wiring the terminator order code 2500A/TERM/MODBUS/RJ45
should be used. This can be plugged into the free socket in the last 2500 base in the chain; it is presumed that
the other end of the cable (usually at the network master) is likewise terminated.
Figure 2-7: Modbus IOC Module and Terminal Unit
2.6.3. The Modbus Address Switch
The base must be given a unique Modbus address when working in a Modbus network. The address can be set
by switch, an 8-way DIP type mounted on the Terminal Unit. It allows addresses 1 to 63 to be set in a binary
code with the right-most six switches, lsb to the right. The left two switches define parity (on/off, odd or even).
Figure 2-8: The Modbus Address Switch
If the Address switch is set to 0 the IOC will use the software defined address in the parameter 'Addr'. This can
be used for base addresses from 64 to 247.
2.6.4. Baud Rate
Baud rate is set using iTools. The default is 9600. The table below shows the rates that are supported in
different software versions:
Software version
Baud rate
V1.XX V2.XX V3.26+
2400
4800
9600
19,200
38,400
Table 2-3: Baud Rates
MB120
AN100
Labels
Moulding
colour
Black
Resistor
Network
1
100Ω 5%
120Ω 5%
8
8
1
P O 32 16 8 4 2 1
P E ..Address..
P Parity On
P Parity off
O
Odd Parity
E Even Parity
Switch Position
ON
OFF
Page 29
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 27
2.7. PROFIBUS IOC AND TERMINAL UNIT
The Profibus IOC is identified by the front label and the order code printed on the side label. This IOC must be
used with a Profibus Terminal Unit. There are two TU options: a standard, a 9-Way D-Type and a dual RJ45 type
as shown in Figure 2-9. The latter is similar to the Modbus terminal unit (Figure 2-6), but must not be confused;
the Modbus unit includes capacitors that could affect high-speed data.
The IOC may be ordered for Profibus DP or Profibus DPv1. Note that for software versions later than v3.43 (and
v4.10) DP/DPv1 may be configured within the IOC (see section 6.2.1).
Figure 2-9: ProfiBus IOC and Terminal Unit
RJ45 Communications
Connectors
Address Switch
9-wa
y
D-Type
Communications
Connector
24V
p
ower supply
terminals
Confi
g
uration
Port
(RS232)
Module connector
LED Status
Indicators
0V +24V
* Termination Links
Fit both links:
1 – 2 to terminate the Profibus network
2 – 3 no termination
Fit suitable termination ONLY on the last device in the chain.
Note: Earlier units were fitted with a single link. On these units this link has no function and the system
should be terminated using the termination plug
On later units fit either the termination unit or both links in position 1 and 2.
1
2
3
0V +24
V
* Termination Links
Page 30
2500 Controller Engineering Handbook
28 Part No HA027115 Issue 4.0 Mar -11
2.7.1. Connections to the Network Connectors
The 9 pin D-Type connector is intended for installations using standard Profibus cables:
Pin No. Signal Name Meaning
1 Shield Shield (ground)
2 Not used
3 RxD/TxD-P Receive/Transmit – Data 'P'
4 Not used
5 DGND Data ground
6 VP Voltage – Plus
7 Not used
8 RxD/TxD-N Receive/Transmit – Data 'N'
9 Not used
Table 2-4: Profibus 9-pin D-TypeConnections
The two RJ45 sockets are parallel connected for network daisy-chaining, with the connections:
RJ45 pin Colour Signal
1 Orange / White Data 'N'
2 Orange Data 'P'
3 Green / White Gnd
4 Blue 5 Blue / White 6 Green +5V
7 Brown / White 8 Brown -
CABLE COLOURS MAY CHANGE!
Table 2-5: RJ45 Profibus Connections
2.7.2. The Profibus Address Switch
The address switch is mounted on the IOC terminal unit. Addresses from 1 to 127 can be set.
Figure 2-10: The Profibus Address Switch
!
64 32 16 8 4 2 1
Profibus Address
The Profibus master will set
the baud rate to cope with
the slowest slave.
Switch Position
ON
OFF
Page 31
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 29
2.7.3. Profibus 9 pin Connector Line Termination
For 9-pin connectors standard Profibus cables should be used. These cables have special headers on the 9-pin
D male connector which allow one or two cables to be connected inot them and have a small termination load
built in with an ON’OFF switch, which is set to ON at the two ends of the links.
The Profibus standard states that two types of cable, ‘Line A’ and ‘Line B’ may be used. The termination details
for these two types of cable are shown below.
Figure 2-11: The Profibus 9-pin Connector Terminations
2.7.4. The RJ45 Profibus Line Terminator
The 9-way connector is not provided with terminators; termination is the responsibility of the network designer.
The RJ45 connector system can be used for local installations for ease of wiring. This requires special
termination impedance (nominal 100Ω). This method of cabling is limited to 16 slaves and must not be directly
connected to a "standard" Profibus cable.
The terminator part number 2500A/TERM/PROFIBUS/RJ45 is designed for this application. Network wiring and
termination techniques are indicated in chapter 10.
Figure 2-12: The Profibus RJ45 Terminator
390Ω 220Ω 390Ω
5 8 3 6
Profibus Line A
390Ω 150Ω 390Ω
5 8 3 6
Profibus Line B
PROFI
Labels
Moulding
colour
Grey
130Ω 1%
180Ω 1%
180Ω 1%
1
8
8
1
Page 32
2500 Controller Engineering Handbook
30 Part No HA027115 Issue 4.0 Mar -11
2.8. DEVICENET IOC AND TERMINAL UNIT
The DeviceNet IOC is identified by the front label and the order code printed on the side label. This IOC must
be used with the DeviceNet Terminal Unit.
Figure 2-13: DeviceNet IOC and Terminal Unit
Address Switch
5-wa
y
DeviceNet
Communications Connector
24V power supply terminals
Confi
g
uration Port
(RS232)
Module connector
LED Status Indicators
1
2
3
4
5
0V +24V
Page 33
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 31
2.8.1. Connections to the Terminal Unit
The DeviceNet Connector is selected to comply with the DeviceNet Open Connector specification (5-way,
5.08mm pitch).
The mating DeviceNet connector (female Open Connector) is supplied to facilitate screw-in user wiring. The pin
functions are marked on the TU.
Pin Number Function
1 V+
2 CAN_H
3 DRAIN
4 CAN_L
5 V-
Table 2-6: 5-Way Connector Pin Functions
2.8.2. DeviceNet Terminators
The DeviceNet specification states that the bus terminators should not be included as any part of a master or
slave. They are not supplied as part of the 2500 DeviceNet termination assembly.
2.8.3. Power
The DeviceNet bus is powered form the system, the load being around 100mA.
2.8.4. The DeviceNet Address Switch
The address switch is mounted on the DeviceNet IOC terminal unit. Addresses from 0 to 63 can be set. The
leftmost two switches may be used to set the DeviceNet baud rate and also to disable the switches, allowing
the baud rate and address to be set by iTools.
Figure 2-14: DeviceNet Address Switch
BAUD 32 16 8 4 2 1
RATE ..Address..
Switch Position
ON (1)
OFF (0)
Sw Baud rate
0 0 125K
0 1 250K
1 0 500K
1 1 Baud and address set
by iTools
Page 34
2500 Controller Engineering Handbook
32 Part No HA027115 Issue 4.0 Mar -11
2.9. ETHERNET IOC AND TERMINAL UNIT
The Ethernet IOC is identified by the front label and the order code printed on the side label. This IOC must be
used with the Ethernet Terminal Unit.
Figure 2-15: Ethernet IOC and Terminal Unit
The Ethernet IOC supports 10BaseT to IEEE802.3 and uses the Modbus TCP protocol.
Address Switch
24V
p
ower supply terminals
Confi
g
uration Port
(RS232)
Module connector
LED Status Indicators
0V +24V
Page 35
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 33
2.9.1. Connections to the RJ45 Socket
The RJ45 socket is connected according to the Ethernet standard.
RJ45 pin Colour Signal
1 Orange /
White
TX+
2 Orange TX-
3 Green / White RX+
4 Blue -
5 Blue / White -
6 Green RX-
7 Brown / White -
8 Brown -
CABLE COLOURS MAY CHANGE!
Table 2-7: RJ45 Ethernet Connections
2.9.2. The Modbus Address Switch
The address (Modbus TCP slave i.d.) switch is mounted on the Ethernet IOC terminal unit. Addresses from 1 to
63 can be set on the rightmost 6 switches. The leftmost switch may be used to enable DHCP Ethernet
addressing.
If all switches are off, the Modbus address and DHCP enable will be determined by the value seen in the iTools
Operator.COMMS list – see section 6.2.
Figure 2-16: Modbus Address Switch
!
D 32 16 8 4 2 1
D Modbus Unit ID
D DHCP enabled
_
D DHCP disabled
Switch Position
ON
OFF
Page 36
2500 Controller Engineering Handbook
34 Part No HA027115 Issue 4.0 Mar -11
3. Chapter 3 iTools
3.1. OVERVIEW
iTools is a Windows® based software package providing a user interface into the 2500 system (as well as other
Eurotherm products). iTools provides tools to configure, commission and monitor any 2500.
iTools implements Modbus RTU communications via any serial port on personal computers under Windows®
95, 98, ME, 2000 or NT version 4.
NOTE: the minimum specification requirements for the PC depend to some extent on the operating system for further details refer to the iTools "ReadMe" file. Any modern PC with at least a Pentium-166, 64M of RAM,
40M of hard disk space free and one serial port free should cope. This is the minimum specification if running
Windows NT.
iTools is started in the conventional way either by double clicking the on screen icon or choosing iTools.exe in
the appropriate folder.
3.2. CONNECTING ANY 2500 TO A PERSONAL COMPUTER
There are three methods of connecting the 2500 system to a Personal Computer (PC) for configuration.
The simplest connection is through the 'Config' port. All versions of IOC support this port (see Chapter 2). The
'Config' port is RS232 compatible, so can be wired directly to any PC COM port with an appropriate adapter
cable.
The other connection methods make use of the network communications port.
The Modbus version IOC requires a converter - RS232 to RS485.
The Ethernet IOC can be connected directly to the network card in the pc by use of a cross-over cable.
Alternatively it can be connected to the same network as the pc using a normal cable.
3.2.1. To Connect a Single 2500 Controller to a PC
Connection of any 2500 to a PC can be made through the RS232 configuration port located on the front of the
IOC module.
This cable plugs directly into the IOC and a COM port of the PC as shown below:
Figure 3-1: Connection between IOC and PC using the 'Config' Port
COM Port
iTools
RJ11 Cable Assembly, Ordering Code
2500A/CABLE/CONFIG/RJ11/9PINDF
PC configuration
station
Power
supply
Fit the plastic cover over the
RJ11 socket when not in use
With this PSU and cable
the IOC can configured
remotely
Page 37
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 35
3.2.2. To Connect multiple 2500 Controllers to a PC
Modbus IOC
A number of Modbus 2500 controllers can be networked together and connected to a network master - iTools.
As the IOC supports RS485 (either 3-wire or 5-wire) a converter is required at the PC COM port. The KD485
RS485/RS232 communications converter is suitable.
All network components (PC, 2500 and KD485) must be set up as appropriate and compatible for a network each slave with a different address, each working with the same baud rate and parity settings, all components to
work 5-wire (duplex) or 3-wire.
Figure 3-2: Connections for multiple Modbus instruments
RJ45 Comms Line
Terminator
Each base must be set
to a unique address
RJ45 Cable Assemblies, Eurotherm Type
2500A/CABLE/MODBUS/RJ45/RJ45/0M5
2500A/CABLE/MODBUS/RJ45/RJ45/3M0
iTools
PC
Fit suitable
termination
resistor on Rx
side
RS485/232
Converter
KD485
RxA RxB TxA TxB
Com
RS232
RS485
Page 38
2500 Controller Engineering Handbook
36 Part No HA027115 Issue 4.0 Mar -11
Ethernet IOC
If the Ethernet IOC is connected directly to the pc using a cross-over cable, any IP address may be used.
Alternatively, the Ethernet IOC must be configured for the network by obtaining a compatible fixed IP address
and Subnet mask or by setting up DHCP – see your Network Administrator.
Figure 3-3: Connections for multiple Ethernet instruments
In order for iTools to be able to detect the Ethernet IOC, it may be necessary to set up the Modbus TCP ports on
the EuroMBus server. To display the server from within iTools, select Options, Advanced, Show Server.
Network
Hub/Switch
RJ45 Cable Assembly, Eurotherm Type
2500A/CABLE/MODBUS/RJ45/RJ45/0M5
2500A/CABLE/MODBUS/RJ45/RJ45/3M0
iTools
PC
Each IOC must be set to a
unique IP address.
Page 39
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 37
Within the EuroMBus server select Add, Ports then click on the TCP/IP tab:
Click Add, or select one of the existing ports and click Edit.
For DHCP addressing, your Network Administrator will allocate a Host name for the instrument. This should be
entered into the Host Name/Address box above. The instrument should be set to DHCP by setting the DIP
switch – see section 2.9.2.
iTools will now search this IP address when scanning for instruments (see section 3.3)
Enter a meaningful name in the Name field.
Enter the IP address in the Host
Name/Address field.
Ensure the Enabled box is checked.
Click OK.
For fixed addressing, this address must be
programmed into the Ethernet IOC using
the configuration cable – see Section 3.2.2.
Page 40
2500 Controller Engineering Handbook
38 Part No HA027115 Issue 4.0 Mar -11
3.3. STARTING iTOOLS - DEVICE DETECTION
As "network master" iTools must identify any and all devices connected to the network - even if just one 2500 is
connected through the 'config' port. On request iTools will automatically search for all devices with unique
network base addresses.
To initiate the search, press the button:
A dialogue might ask for a start address. For a single IOC connected from the 'Config' port leave the start at
255; for networking multiple systems save time by specifying the lowest address used.
When all connected instruments have been found appropriate icons are a displayed in the Panel window
(assuming Panel Views has been checked in the View menu):
Figure 3-4: 2500 icons in the Panel View window
To save time (in a large network) it is possible to stop iTools scanning by pressing the Stop Scan button once all
relevant bases have been identified.
To work with any particular base simply click the appropriate icon.
If working with a single IOC through the 'Config' port (and no other ports enabled) the network scan stops
automatically and the device is automatically selected.
3.4. SETTING ACCESS LEVEL
The IOC can run in different modes, as discussed in Chapter 2 (section 2.2). The 'Operating' or 'Run' mode in
particular limits access to features; the most important of which is that critical loop parameters are secured, to
prevent accidental changes to an active process.
The 'Configuration' or 'Config' mode provides full access to parameters for set-up, but limits functions; in
particular, output channels are limited to OFF (digital outputs) or electrical low (analogue outputs). Note this
particularly when testing output channels.
3.4.1. Operating Mode
For most of its working life the IOC will be in 'Operating' or 'Run' mode, executing the programmed control
strategy. In this mode inputs and outputs are active, PID loops and Toolkit Blocks operate and the internal
database regularly updated. Any network master can use the communications link to access the database and
the parameters.
iTools will indicate that any connected 2500 is in operating mode by displaying the 2500 icon with no additional
symbols. On the IOC the top (green) indicator LED marked “” is on.
3.4.2. Configuration Mode
'Configuration' or 'Config' mode is designed precisely for set-up of any 2500 system. The 2500 is shipped with
a collection of useful tools but no strategy. To configure the 2500 for useful applications the user must define
the needed I/O modules and "wire" the blocks together to perform the required task. Sometimes changes are
made on-site; for this reason, when the 2500 is in configuration mode it is NO LONGER controlling. Outputs
drive is effectively disabled.
When the 2500 is in configuration mode the iTools icon is displayed with a yellow wrench symbol. On
the IOC the yellow indicator LED marked “C” is on.
Page 41
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 39
3.4.3. Standby Mode.
'Standby' mode is normally a transient state that the IOC enters while changing modes or when a fault is
detected. In Standby mode the IOC is not controlling but is also not in configuration mode. This mode should
not be deliberately set by the user.
When the 2500 is in standby mode the iTools icon is displayed with a yellow hand symbol. On the IOC
the yellow indicator LED marked “S” is on.
3.4.4. Changing Mode
There are several ways to change the IOC run mode.
To enter 'Config' mode directly from iTools:-
1. Click the “Access” button on the Toolbar, or
2. Right click on the Instrument View (or the device name in the Device Browser). From the pop up menu
select Set Acce
ss Level Configuration, or
3. From the menu bar, click D
evice Set Access Level Configuration.
When changing from 'Run' to 'Config' mode a warning is displayed on iTools, but no password or security code
is required.
Alternatively, simply power up the 2500 with iTools and the RJ11 'Config' connector plugged into the IOC
'Config' socket. This connection forces the 'Config' mode.
To enter 'Run' mode from iTools:
1. Click the “Access” button on the Toolbar, or
2. Right click on the Instrument View (or the device name in the Device Browser). From the pop up menu
select Set Access Level Operator, or
3. From the menu bar, click D
evice Set Access Level Operator
Page 42
2500 Controller Engineering Handbook
40 Part No HA027115 Issue 4.0 Mar -11
3.5. INSTRUMENT PARAMETERS
In the 2500 system "Parameters" are the numbers and values that represent the state of the machine. Each
available parameter has a predefined address in the database. Parameters in iTools are organised into folders
which are applicable to a particular subject. For example, to find a loop alarm setpoint go to Control →
LOOP(number) → LO(number)ALM in the browser in iTools.
Parameter values are of just two type: Real Values or Enumerated Values. The former is altered from a dialogue
window simply by typing in a new value. Enumerated values require a selection from predefined options from a
pull down list. iTools displays each enumerated item with an integer value in brackets - the enumeration value.
This is the value that would be used over network communications for reading or writing a new parameter
value.
Parameters are given fixed attributes, so may be Read Only or Read/Write. Read Only parameters are
displayed in blue and Read/Write parameters are shown in black in the parameter lists. Only Read/Write values
can be changed, and some parameters, such as configuration parameters, can only be changed if the access
level is appropriate.
iTools also allows irrelevant parameters to be hidden from view, reducing screen clutter.
Once iTools has detected a 2500 system it is ready to display Parameter Lists for operation, monitoring or
configuration.
3.5.1. To Display Parameters
Parameters are collected into related lists. Controller Parameter Lists may be displayed in several ways:
1. Double click on the required instrument view (or the instrument name in the Device Browser), or
2. Right click on the instrument view (or the instrument name in the Device Browser) and select P
arameter List
from the pop up window, or
3. Left click on the required instrument view. From the Toolbar click Device Views followed by Parameter
List.
3.5.2. To Find a Parameter
If it is not known in which list the parameter resides, press the ‘Find’ tab which is located at the at the bottom of
the browser section.
You may search on
Parameter Names
Descriptions
Addresses
Comments
Page 43
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 41
3.5.3. To Change Parameter Values
The first step is to invoke the parameter edit dialogue. There are several methods:-
1. From the Parameter List window double click on the selected parameter; or
2. From the Parameter List window right click on the selected parameter, and from the pop up menu select
Edit Parameter Value; or
3. From the menu bar select Parameter List and from the pop up menu select Edit Parameter Value
A pop up window will appear:
Figure 3-5: Parameter value dialog
The edit method depends upon parameter type. If real (as in Figure 3-5 above) then simply type in the new
value, then set by clicking the "A
pply" dialogue button (if you want to use the same dialogue again), or click the
"OK" button if finished with the dialogue.
If the parameter offers a list the dialogue looks more like:
Figure 3-6: Enumerated value dialog
Select the desired value from the pull-down list and click "OK" or "Apply" as before.
Note that to change the above parameter example over network communications, say to AUTO, write the value
0 to the parameter address; for manual MAN write 1.
3.5.4. Example: To Set Baud Rate
1. From the Device Browser, click Operator → COMMS → Baud (in the right hand window)
2. Double click this parameter
3. From the pop up window click ""
4. Select the required baud rate, and click OK or Apply
The baud rate can only be changed if the 2500 is in Configuration Mode and it is appropriate to the
Communication protocol
3.5.5. Failure To Write a New Value
If an attempt to write a new parameter value is unsuccessful the message ‘Value Rejected by Device’ might
appear.
This could happen if the controller is not in configuration mode and the parameter selected is a configuration
parameter.
Alternatively, an incorrect condition has been requested. For example, if a module is configured as a Digital
Input, selecting a parameter associated with any other type (AO, AI or DO) will be rejected.
Note that there are many situations, particularly in Configuration Mode, where a new value is not formally
rejected, it is just ignored.
Page 44
2500 Controller Engineering Handbook
42 Part No HA027115 Issue 4.0 Mar -11
3.6. PARAMETER AVAILABILITY AND ALTERABILITY
A very large number of parameters are pre-defined in the 2500
system.
The Navigation tree example shown, taken from the iTools
browser, shows the top list of folders available on a 2500 with 4
way base.
iTools can hide folders and parameters that are not relevant to a
particular set-up. In this list iTools knows it is a 4 way base and has
removed the I/O folders for I/O modules 5 to 16. Note that this
"list hiding" is delayed at start-up while the IOC communicates the
parameter values and settings and synchronises its data base.
In the same way iTools will hide and expose parameters
depending on the actual configuration of the 2500 Unit and its
mode – whether it is in Operating mode, Configuration mode or in
Standby
The List window will display the list associated with one of these
folders - simply double-click on the folder to be viewed.
Figure 3-7: Browser view of 2500 folders
For example, a double-click on the
LOOP1 folder (of Figure 3-6) will
display a list perhaps similar to this:
Note: from the title bar the identifier
COM1.ID255-2500-v222. This
identifies the device completely
through the network connection:
Figure 3-8: LOOP1 parameter list
COM1 - the port on the PC running iTools that is connected to the 2500
ID255 - the Modbus address, in this case via the IOC configuration port
2500 - the product code
V222 - the software version number.
From the folder line below the title bar the path to the highlighted parameter on the navigation tree is:-
Control → LOOP01 → L01PID → PB (the PID loop proportional band).
By default only ‘available’ or relevant parameters appear on a page. For example, relative cool gain does not
appear in a heat only controller, and integral time does not appear in an On/Off controller.
A parameter may be Read Only with the 2500 in operating mode, but Read/Write in Configuration mode. An
example is thermocouple linearisation type.
Parameters coloured in black are Read/Write.
Parameters coloured in blue are Read Only.
Parameters in a grey banner are read only and depend upon the setting of another parameter. For example,
‘SP Rate Limit Holdback Value’ can only be altered if ‘SP Rate Limit Holdback Type ≠ OFF.
See Chapter 4
See Cha
p
ter 5
See Cha
p
ter 6
See Chapter 7
See Chapter 8
See Cha
p
ters
9, 10, 11 and 12
See Chapter 8
Page 45
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 43
3.7. SETTING UP AN APPLICATION
The 2500 can be set up to provide a wide range of application solutions. To this end it offers I/O channel
blocks, I/O module blocks, PID loop blocks, timer blocks, counter blocks... and more.
To create any control strategy the Applications Engineer can connect these blocks together using software
‘wiring’ in whatever way is needed to provide the required control functions.
3.7.1. What is a Function Block?
A function block is a software entity that performs a particular task upon 'input' data to compute 'output' values.
The actual algorithm may be dependent upon other input settings.
For example, an input channel is a block - the terminal signal being the 'input', the reported PV the output. The
parameter 'Channel Type' will modify the response. The COUNTER block is a purely computational block,
producing a count value 'output' from and event 'input'. Note that there are usually several instances of each
function block type; for example, there might be eight PID loop blocks.
3.7.2. Why use Function Blocks?
Function Blocks are tested building blocks intended to provide general purpose tools to allow speedy
construction of complex systems. This methodology reduces problems and speeds up the design cycle while
retaining the flexibility to produce different applications.
3.7.3. Function Block Wiring Example
To make use of function blocks the various inputs and outputs must be interconnected - "wired". This software
"wiring" (not to be confused with electrical wiring!) is a method of passing an output parameter value to the
input parameter of another block.
Consider the simple task below, to set up a temperature control loop:
Figure 3-9: Example of function block wiring
To implement the temperature control loop a LOOP block is selected - here LOOP01. To make the loop
dependant upon temperature the output value (PV) of the AI3 block must be wired to the PV input of the LO01
PID block.
Note in this example a temperature measurement device (thermocouple) is wired (literally, in the electrical
sense) to the Channel 1 terminals of the AI3 Module, which is in the base slot 3.
To add the loop PV wire use the iTools 'Browse' pane to navigate to LOOP01 and double-click to show the
parameter list, which might look something like Figure 3-10:
Note that the Process Variable
(PV) and ‘PVSrc’ parameters
are not wired by default. Note
also the 'Address' column;
every parameter in the 2500
has a unique Modbus
address, and this address is
used to identify each end of
the 'wire'. In the window
above the Process Value
‘Source’ has a value –1, which
indicates no wire.
It is this parameter that we
need to alter, defining the
address of the PV value from
the AI3.
Figure 3-10: Loop parameter lists
Plant Wiring
Analogue Input Module
AI3
Module 3 PV
Channel 1
LOOP 1
PID Block
SP OP
PV
‘Soft’ Wirin
g
Page 46
2500 Controller Engineering Handbook
44 Part No HA027115 Issue 4.0 Mar -11
We need to identify the AI3 channel output (PV) address; navigate as usual to that list:
Figure 3-11: AI3 channel list
We can see the parameter 'Val' is at address 5207. We could have found this by looking up the published
Modbus parameter information.
Reverting to the LOOP list (Figure 3-10), enter the new address (5207) into the PVSrc Value the new parameter
will look like:
Figure 3-12: PID Function Block View with Wiring
To extend this example further, the loop output should be wired to an output channel; the set point wired to a
fixed value, or to a setpoint controller.
Complex systems can be constructed in a very short time using the above procedure.
Page 47
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 45
3.8. DECLARING I/O MODULES
Each type of 2500 I/O module is
identified with a unique code. The
IOC regularly scans every base slot
for module type codes; thus can
verify any software configuration
against actual modules fitted. This
system also allows for "hot swap"
of modules in service.
The iTools I/O module lists show
two parameters 'ReqID' and
'ActID'. The former must be set to
define the needed module type,
the latter confirms the type actually
fitted. These parameters are found
in IO → Modulexx → MODxx.
In the 2500 system EVERY required
module must be declared and
identified. If not declared (or the
wrong type fitted) the module will
not function. Note, the green
indicator LED on I/O modules only lights if the module is correctly identified and initialised. If the IOC detects
any miss-match the red "X" indicator illuminates.
To set the ‘ReqID’ parameter to match the I/O module navigate to the module block list as shown in the
example in Figure 3-13:
Figure 3-13: Selecting a module type
Double-click the ‘ReqID’ parameter and select the module type from the drop-down list in the usual way.
3.9. THE WIRING EDITOR
Wiring can become quite complex in a large system. To help control wiring there is an editor in the Toolkit
Block components that provides a view of all wiring connections within a 2500 controller. The editor also
contains a full list of all the available Wireable Parameters and where they are wired from.
The Block Wiring Editor in Toolkit Blocks can be opened in a number of ways:-
1. From the toolbar click unext
to Views
2. From the V
iew menu
3. Right click on the icon view or
the device name in the Device
Browser
This opens up a Window with 4
tabbed lists. The first three tabs
are for the Toolkit Blocks which
are covered in Chapter 8.
The fourth list is the ‘Block Wiring’,
with all the wireable parameters
and all their connections within
the 2500. It is possible to do all
the wiring using this editor alone.
Figure 3-14: The wiring editor
Because there are potentially a very large number of wireable parameters in a 2500 the list is split up into
sections and a pull down list “Show Parameters” is used for selection.
Wiring can be added as before, by double-clicking or right-clicking on the row required in the ‘Wired From’
column. Wiring can also be made by using Windows drag and drop; for example, taking the
Control.LOOP01.L01_OP.Ch1OP parameter from the device browser (or from the Parameter List) and dropping
it on the IO.Module04.M04C1.Val in the Block Wiring page above.
Page 48
2500 Controller Engineering Handbook
46 Part No HA027115 Issue 4.0 Mar -11
4. Chapter 4 Control
4.1. ABOUT THIS SECTION
The IOC fitted in the 2500 DIN Rail Controller has a number of options, such as 2, 4 or 8 loops of control and
Toolkit Blocks depending upon the option ordered. This section applies to any number of loops. Toolkit blocks
are described in Chapter 8.
The loop type can be configured as:
Loop Type For further description see section:-
Single PID 4.4
Single On/ Off 4.3
Valve Position (Bounded or Boundless) 4.8.3, 4.8.4
Cascade pair 4.10
Override pair 4.11
Ratio 4.9
In its simplest form a Control Loop can be represented by the diagram below.
Figure 4-1: A PID Loop
The loop function block has inputs from a Setpoint Function block and a Process Variable measurement.
Outputs from the loop function block may be wired to control plant actuators. Alarm conditions can be added
to monitor plant conditions. Auto and Manual Tuning of the loop parameters can be made to suit the
characteristics of the plant. This chapter describes these options and how to set them up, all based on LOOP0x,
where x = 1 to 8.
Section 4.2 Standard ‘view’ of a loop in iTools
Section 4.3 Key configuration parameters ‘Loop Type’, ‘Control Type’
Section 4.5 Sets of tuning parameters, ‘gain scheduling’
Section 4.6 Setpoints and how to select setpoints
Section 4.8 Outputs, Dual outputs, output demand limit, Heat Cool
Section 4.9 4.10 4.11 Advanced Loops:- Ratio, Cascade, Override
Section 4.13 Auto tune
Section 4.14 Diagnostics
Section 4.15 Loop Alarms
4.2. LOOP VIEW
This is the top Parameter List of a Loop in iTools. In most configurations these parameters are Read Only and
show how the loop is performing. The Process Variable would normally be wired to the analogue input
requiring to be controlled. Target Setpoint and Auto Manual would be writeable in simple applications.
Figure 4-2: Loop Overview
Out
p
ut Section 4.8
Auto Tune Section 4.13
Tunin
g
Parameters Section 4.5
Set
p
oint Section 4.6
Process Variable
Loop Type
Section 4.3
Dia
g
nostics Section 4.14
Alarms Section 4.15
Page 49
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 47
4.2.1. Loop Overview Parameters
These parameters are in the Control → LOOP0x list.
Name Description Range Status
PV
Process Variable. The input process value to be controlled by the loop. The current
value of the variable from the wired source, for example an Analogue Input module
¦9
PVSrc
Process Variable Source. Modbus address of the parameter wired to the PV. -1
indicates NOT wired.
wSP
Working Setpoint. The Working Setpoint is the current value of the setpoint being
used by the control loop. It may come from a number of different sources, such as an
internal SP, Remote SP or Next Slave Instrument SP (see section 4.6)
¦9
tSP
Target Setpoint. The Target Setpoint is the value of setpoint at which the control loop
is aiming. It may come from a number of different sources, such as an internal SP,
Remote SP or Next Slave Instrument SP (see section 4.6)
¦9
T_OP
Target Output Power. The output demand the loop calculates is required before
external limits are applied.
¦%
T_OPSrc
Process Variable Source. Modbus address of the parameter wired to the T_OP. -1
indicates NOT wired.
wOP
Working Output. The current value of the output demand signal from the loop.
¦%
m-A
Auto/Manual Select. If this is not wired this allows the output demand to be set for
manual or automatic:-
Auto (0) Automatic The output demand is provided by the control loop
mAn (1) Manual The output demand can be set by the operator using the ‘Target Setpoint’ parameter. When
changing from Auto to Manual the output demand will remain at the current value until it is raised or
lowered by the operator. When changing from Manual to Auto the output demand will assume the previous
manually set value then change in a controlled manner to the value demanded by the control loop. This is
referred to as ‘Bumpless Transfer’.
m-Asrc
Auto/Manual Select Source. This allows the Auto/Manual
select to be wired to a parameter.
CtSbyAct
Control Action in Standby. The action the Control
algorithm will take when in Standby mode.
Suspnd (0)
Suspend the loop:
Cont (1)
Continue running the loop.
SbrSt
Sensor Break Status Flag. Either hardware fault from input
or linearised input PV out of range
no (0)
Sensor working normally
YES (1)
Sensor in a break condition. This may be open circuit or high impedance
XFb
External (or Remote) OP Feedback. Allows an external
source of feedback to stop Integral wind-up
¦9
XFbSrc
External Feedback Source. Modbus address of the
parameter wired to the ExtFB. -1 indicates NOT wired.
The following parameters may be hidden if not required for the operation of the instrument. To reveal uncheck the ‘Hide
Parameters’ box in ‘Options → Parameter Availability Settings’
o-oOP
On Off Control Output. For ON/OFF control the actual
output demand is:
-100 (0)
Maximum 'Cool' demand (Full output demand for Direct acting loop)\
0 (1)
No output demand
+100 (2)
Maximum 'Heat' output demand (Full demand for Reverse acting loop)
V_POS
Valve Position. Actual position of potentiometer if
connected or inferred position if no potentiometer fitted
¦%
SPorig
Setpiont Origin. Defines where the PID Setpoint comes
from:
Intern (0)
the internal setpoint of the PID block
Remote (1)
the Remote Setpoint\
Progrm (2)
the Programmer Ramp Block
WSPHi
Maximum value allowed for the working setpoint ¦9
WSPLo
Minimum value allowed for the working setpoint ¦9
Page 50
2500 Controller Engineering Handbook
48 Part No HA027115 Issue 4.0 Mar -11
4.3. LOOP CONFIGURATION
This is the page used to set up or configure the way in which the loop is designed to operate. In Configuration
Mode ALL these parameters are Read/Write, in Operating Mode ALL these parameters are Read ONLY.
Figure 4-3: Loop Configuration
4.3.1. Key Configuration Parameters.
These parameters are in the Control → LOOP0x → L0xCFG list.
The following four configuration parameters must be set to suit the application.
LpType
Loop Type. This is first main selection and defines the structure of the loop.
Single (0)
Single Loop Control
Cascde (1)
Cascade Control (See Section 4.10)
Overid (2)
Override Control (See Section 4.11)
Ratio (3)
Ratio Control (See Section 4.9)
Ctrl
Control Type. This is the second main selection and defines the behaviour and outputs of the loop. A
control loop may have a single channel output (eg Heat Only) or Dual channel (eg Heat/Cool). The
control algorithm may be PID, or a raise/lower Valve Positioning algorithm. The Valve Position
algorithm may be configured for use with position feedback from a potentiometer (‘Bounded’ or
Position Mode control), or without position feedback (‘Boundless’ or Velocity Mode control).
Single outputs: Channel 1. Numbers shown in ( ) are enumerated values
PID (0)
PID control
OnOff (1)
ON/OFF control
VPU (2)
Valve Control - boundless
VPB (3)
Valve control – bounded
Dual outputs:.
Channel 1 Channel 2
PID1&2(4)
PID (Heat) PID (Cool)
PID On(5)
PID ON/OFF
On1&2(6)
ON/OFF PID
see not
e
OnVPU(7)
ON/OFF Valve Control – boundless
see not
e
OnVPB(8)
ON/OFF Valve control – bounded
see not
e
VPUOn(9)
Valve Control – boundless ON/OFF
VPBOn(10)
Valve control – bounded ON/OFF
PIDVPU(11)
PID Valve Control – boundless
Next Phas
e
PIDVPB(12)
PID Valve control – bounded
Next Phas
e
VPU1&2(13)
Valve Control – boundless Valve Control – boundless
Next Phas
e
VPUVPB(14)
Valve Control – boundless Valve control – bounded
Next Phas
e
VPB1&2(15)
Valve control – bounded Valve control – bounded
Next Phas
e
VPBVPU(16)
Valve control – bounded Valve Control – boundless
Next Phas
e
Note: Select Direct Control Action (below) and ON/OFF as Channel 2.
Act
Control Action. This applies to Channel 1, Channel 2 will be the opposite
rEv (0) Reverse action - the output will increase positively if PV is below SP. (Eg Heat)
dir (1) Direct action - the output will increase positively if the PV is above SP. (Eg Cool)
rnGH/L
Process Value High and Low Limits. These must reflect the active range of the controlled variable and
will be used to scale the PID action, for example, to calculate the proportional band in %. Outside these
limits the Sensor Break flag will be active
The remaining configuration parameters also affect how the loop is used and are taken in the order listed:
Page 51
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 49
4.3.2. Other Loop Configuration Parameters
Name Description Range Status
COOL
Cooling Type This applies to the PID output on Channel 2
Lin (0) Linear The control output follows linearly the PID output signal, i.e. 0% PID demand = 0 demand output,
100% PID demand = 100% demand output.
oiL (1) Oil, Water, Fan The control output is characterised to compensate for the non-linear effect of the cooling
medium - oil, water and blown air. Typically used in extrusion processes.
H20 (2)
FAn (3)
ProP (4) Prop Cooling output is proportional to error
titd
Integral & Derivative Time Units Usually seconds, but may be changed to minutes or
hours
dtyP
Derivative Type Derivative on PV defines that derivative action responds to
changes to PV only
Derivative on Error defines that derivative action responds to changes to differences
between SP and PV, better for ramping setpoints
PwrF
Power Feedback Enable If the supply voltage changes the PID output is
immediately modified to keep the output demand constant.
Power feedback is generally used in a heating application to compensate for supply
voltage changes before the effect is seen in the temperature. For outputs controlling
contactors or SSRs set power feedback to on. For outputs controlling analogue
thyristor units PwrF would normally be set to OFF since the thyristor unit generally
contains its own local compensation.
OFF (0) Off No power feedback
on (1) On Power feedback enabled
Fwdt
Feedforward Type Feedforward control is used typically to overcome time
delays or to compensate for the effect of external influences such as control signals
from other loops in the process. This is added directly to the output of the PID
algorithm, before output limiting and dual output conversions are performed. Trim
Limit applied to the PID calculated output is possible when Feedforward is enabled.
Pdtr
Manual/Auto Transfer PD Control Defines the control output behaviour for
Manual/Auto transfer when there is no integral term:
no (0) No Manual to Auto transfer will bump
YES (1) Yes Manual to Auto transfer will be bumpless
Sbrt
Sensor Break type. On sensor break detection the output demand will revert
to:-
Sb.OP (0) Sb.OP to a preset value set by ‘oSbOP’ in ‘L0x_OP’ list
HoLd (1) Hold to its current value
FOP
Force Manual Output Mode. Force Manual Mode allows you to select how the
loop behaves on auto/ manual transfer
no (0) Off Transfer between auto/manual/auto takes place bumplessly
trAc (1) Track Transfer from auto to manual, the output reverts to the previous
manual value. Transfer from
manual to auto takes place bumplessly
StEP (2)
Step Transfer from auto to manual, the output goes to a pre-set value L01_OP.FOP.
Transfer from manual to auto takes place bumplessly
Pbu
Proportional Band Units. Units in which the Proportional band is set
EnG (0) Eng in engineering units
% (1) % as a percentage of the input range
dEcP
Decimal Places in Disp/Comms. Defines the resolution of the main PV and Setpoint as
seen by digital communications
nnnn (0)
No decimal places
nnn.n (1)
One decimal place ie 123.4 is sent as 1234
nn.nn (2)
Two decimal places ie 12.34 is sent as 1234
WSPRmp
Ramp from WSP. When ramping SP is enabled, this parameter determines the
starting point of the ramp
no (0)
Ramp from PV
YES (1)
Ramp from WSP
Page 52
2500 Controller Engineering Handbook
50 Part No HA027115 Issue 4.0 Mar -11
4.4. PID CONTROL
PID control, also referred to as ‘Three Term Control’, is a technique used to achieve stable straight line control at
the required setpoint. The three terms are:
P Proportional band
I Integral time
D Derivative time
The output from the controller is the sum of the contributions from these three terms. The combined output is a
function of the magnitude and duration of the error signal, and the rate of change of the process value. It is
possible to set P, PI, PD or PID control.
4.4.1. Proportional Term
The proportional term delivers an output which is proportional to the size of the error signal. An example of this
is shown in Figure 4-4, for a temperature control loop, where the proportional band is 10
O
C and an error of 3OC
will produce an output of 30%.
Figure 4-4: Proportional Action
Proportional only controllers will, in general, provide stable straight line control, but with an offset
corresponding to the point at which the output demand equals the heat loss from the system.
4.4.2. Integral Term
The integral term removes steady state control offset by ramping the output up or down in proportion to the
amplitude and duration of the error signal. The ramp rate (reset rate) is the integral time constant, and must be
longer than the time constant of the process to avoid oscillations.
4.4.3. Derivative Term
The derivative term is proportional to the rate of change of the temperature or process value. It is used to
prevent overshoot and undershoot of the setpoint by introducing an anticipatory action. The derivative term
has another beneficial effect. If the process value falls rapidly, due, for example, an oven door being opened
during operation, and a wide proportional band is set the response of a PI controller can be quite slow. The
derivative term modifies the proportional band according to this rate of change having the effect of narrowing
the proportional band. Derivative action, therefore, improves the recovery time of a process automatically when
the process value changes rapidly.
Derivative can be calculated on change of PV or change of Error. For applications such as furnace control, it is
common practice to select Derivative on PV to prevent thermal shock caused by a sudden change of output
following a change in setpoint.
Proportional
band
3
O
C error
Tem
p
erature
Setpoint
10
O
C
Output
100%
0%
30%
Page 53
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 51
4.4.4. High and Low Cutback
While the PID parameters are optimised for steady state control at or near the setpoint, high and low cutback
parameters are used to reduce overshoot and undershoot for large step changes in the process. They
respectively set the number of degrees above and below setpoint at which the controller will start to increase or
cutback the output demand.
Figure 4-5: High and Low Cutback
4.4.5. PID Block Diagram
Figure 4-6: PID Block Diagram
Overshoot
To reduce the overshoot
increase the low cutback value
Undershoot
To reduce the undershoot
decrease the low cutback value
Dual OP
<0.0
SP
PV
SP High Limit
SP Low Limit
Ran
g
e Ma
x
Range Min
Feedforward
+
#
Remote
Feedforward *
Inte
g
ral Hold
+
-
-1
Control Action
Direct
Reverse
Error
PV
Inte
g
ral (or
Man Reset)
Derivative
OP Track
Enable
PID OP
Track Enable *
+
Track Value
OPH
OPL
Auto
Manual
Rem OP Hi *
Rem OP Lo *
OP Rate Limit
Manual *
>0.0
Relative
Cool Gain
Ch 1 OP
Ch 2 OP
Remote out
p
ut
feedback
Page 54
2500 Controller Engineering Handbook
52 Part No HA027115 Issue 4.0 Mar -11
4.4.6. PID Parameters
These parameters are in Control → LOOP0x → L0xPID.
The L0xPID List displays all the current working PID parameter values. These are all read only (coloured blue)
and are set either following an Autotune (section 4.13) or adjusted manually (section 4.5.1 ‘PID Sets’). The PID
terms have been described in previous pages.
Figure 4-7: PID Parameter List
Name Description Range Status
PB
The proportional band value the PID is using now. Units (Eng, %) are set in Control →
LOOP0x → LoxCFG → Pbu
Ti
The integral time the PID is using now. Units (Sec, Min, Hour) are set in Control →
LOOP0x → L0xCFG → titd
Td
The derivative time the PID is using now. Units (Sec, Min, Hour) are set in Control →
LOOP0x → L0xCFG → titd
rES
The Manual reset value the PD controller is using now
Hcb
The cutback high value the PID is using now
Auto (0) Auto The cutback value is set by the PID Block
Value
The cutback value set manually in Control → LOOP0x → L0xSET → Hcb1
Lcb
The cutback low value the PID is using now
Auto (0) Auto The cutback value is set by the PID Block
Value
The cutback value set manually in Control → LOOP0x → L0xSET → Lcb1
reL
The Channel 1 Channel 2 Relative gain value the PID is using now
SET
Working PID Set. Selects which of the 3 sets of tuning parameters is being used.
Selection is Manual or by Gain Scheduling (section 4.5.). Note that Control.LOOP0x →
L0xSET → nSets must be a value > 1.
SETSrc
Modbus address of parameter value used as the working PID set
FF
Remote Feedforward Remote input value used as a feedforward. Feedforward must
enabled in L01CFG → Feedforward type.
FFSrc
Modbus address of parameter value used as the remote feed forward
-1 indicates NOT wired.
Frz
Freeze Control Flag Value Freeze Control flag may be set to suspend PID calculation
and all the calculated values remain frozen. This parameter is wireable
FrzSrc
Modbus address of parameter value used as the freeze control flag
LPBrk
Loop Break Status Flag. PID loop detects that the output has remained on a limit and
PV has not moved by half proportional band for > Loop Break Time
no (0)
No Loop status is OK
YES (1)
Yes Loop status is detected as broken - open loop
Lb_t
Loop Break Time Flag is set when the PID loop detects that the output has
remained on a limit and the PV has not moved by half the proportional band during the
Loop Break Time.
I_Hold
Integral Hold Flag Set to suspend the Integral calculation and hold constant the current
integral contribution to the output value. This parameter is wireable
Page 55
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 53
Name Description Range Status
I-HSrc
Modbus address of the flag used to hold the Integral value
-1 means not wired
Debump
Debump Flag Set to balance integral to maintain the same output demand. Flag
resets itself
Adc
Manual Reset Auto Calc Enable With Integral Time OFF, setting Adc enables calculation
of the Manual Reset. If Adc is not set Manual Reset must be set manually
The following parameters may be hidden if not required for the operation of the instrument. To reveal uncheck the ‘Hide
Parameters’ box in ‘Options → Parameter Availability Settings’
FFPb
Proportion of feed forward fed directly to the output - Default 100 decreasing value
increases the effect
FFtr
Fixed offset value added to the feedforward signal
FFdv
SP and PV feed forward defines range of PID trim contribution. Feedforward is limited
directly.
MaxDsp
For diagnostic use only
MinDsp
For diagnostic use only
MnPosn
For diagnostic use only
MxTDTI
For diagnostic use only
Page 56
2500 Controller Engineering Handbook
54 Part No HA027115 Issue 4.0 Mar -11
4.5. GAIN SCHEDULING
Gain scheduling is the automatic transfer of control between one set of PID values and another. Gain
scheduling may be used in very non-linear systems where the control process exhibits large changes in
response time or sensitivity, see Figure 4-8 below. This may occur, for example, over a wide range of PV, or
between heating or cooling where the rates of response may be significantly different. Up to are three sets of
PID values may be chosen -the number of sets depends on the non-linearity of the system. Each PID set is
chosen to operate over a limited (approximately linear) range.
The active set can be selected from:
1. A digital input
2. A parameter ‘ Working PID Set’ in the L0xPID list
3. Or you can transfer automatically in gain scheduling mode.
Figure 4-8: Gain Scheduling in a Non-linear System
4.5.1. Gain Scheduling Parameters - PID Sets
These parameters are in the Control → LOOP0x → L0xSET list. They are not available if Control Type = OnOff
in Control → LOOP0x → L0xCFG.
Figure 4-9: PID Parameter Sets
SP
Controlled
Variable
PID
Set 1
PID
Set 2
bound1
bound2
Page 57
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 55
The default set up of the loop provides a single set of PID values – all Read/Write. There are 3 sets of PID values
available and different strategies to select to change from one PID set to the next. These two parameters may
only be changed in configuration level.
Name Description Range Status
nSets
Number of PID sets to Use. For Gain Scheduling
1, 2, 3
PidSch
Scheduling Type
OFF (0)
Off SET 1 is used all the time
SET (1)
SET No strategy, enabled sets may be selected using L0xPID.SET
SP (2)
SP New set is selected when the Setpoint crosses the value of bound1 and bound2
PV (3)
PV New set is selected when the PV crosses the value of bound1 and bound2
ER (4)
ER New set is selected when the Error crosses the value of bound1 and bound2
OP (5)
OP New set is selected when the Output crosses the value of bound1 and bound2
RM (6)
RM New set is selected when the Remote Scheduling Input crosses the value of bound1 and bound2
WIRE (7)
WIRE Gain Scheduling is implemented by wiring to the PID terms using XpSrc, TiSrc, TdSrc.
RM
Remote Scheduling Input. The value used to control the active set when Scheduling
type is set to RM.
RMSrc
Remote Scheduling Input Source. Modbus address of the parameter supplying the
value for RM. –1 means it is not wired.
AnVal
The current analogue value selected form AnVal1 to AnVal3
bound1
Boundary for change from Gain Scheduling Set 1 to Set 2\nDepends on the
Scheduling type selected
bound2
Boundary for change from Gain Scheduling Set 2 to Set 3\nDepends on the
Scheduling type selected
XpSrc
Proportional Band Source. Modbus address of the parameter supplying the value
for Prop Band when the Scheduling type is set to WIRE. –1 means it is not wired.
TiSrc
Integral Time Source. Modbus address of the parameter supplying the value for
Integral Time when the Scheduling type is set to WIRE.. –1 means it is not wired.
TdSrc
Derivative Time Source. Modbus address of the parameter supplying the value for
Derivative Time when the Scheduling type is set to WIRE.. –1 means it is not wired.
Parameters PB1, Ti1, Td1, rES1, Hcb1, LcB1, rEL1 are the PID parameters for set 1. They are the same as those
described in section 4.4.6. and are repeated for sets 2 and 3.
Parameters OPH1, OPL1 to OPH3, OPL3 are the output limit parameters for each set which are the same as
those described in section 4.8.2.
Parameters AnVal1 to 3. are customisable parameters which provide additional flexibility when designing a
control strategy. They are available for each set when gain scheduling has been configured and for each loop
configured. They can be ‘soft wired’ to perform a specific function relevant to the particular process being
controlled. Examples include: Output Power Limit, SP feedforward Trim, etc.
Page 58
2500 Controller Engineering Handbook
56 Part No HA027115 Issue 4.0 Mar -11
4.6. LOOP SETPOINT
This page is used to configure parameters which define the setpoint to a control loop.
Figure 4-10: Loop Setpoint
The Working Setpoint is the setpoint used by the control loop and may be derived from a number of different
sources.
4.6.1. Setpoint Parameters
These parameters are in the Control → LOOP0x → L0x_SP list.
Name Description Range Status
SSESrc
Internal SP Select Source Modbus address of the flag used to select SP1 or SP2 -1
means it is not wired
SSEL
Internal Setpoint Select. If this is not wired the setpoint can be selected from:-
SP1 (0)
Setpoint 1 Internal setpoint 1
SP2 (1)
Setpoint 2 Internal setpoint 2
SP1/2Src
Modbus address of the parameter supplying the value of SP1/2 -1 means it is not
wired
SP1/2
Current value of SP1/2 Note Control → LOOPnn → Lnn_SP → L-r must not be set.
SP_L
Minimum value allowed on SP1 ¦%
SP_H
Maximum value allowed on SP1 ¦%
SP_2L
Minimum value allowed on SP2 ¦%
SP_2H
Maximum value allowed on SP2 ¦%
Page 59
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 57
4.6.2. Rate Limit and Holdback Parameters
These parameters are also in the Control → LOOP0x → L0x_SP list.
Holdback is used to stop the setpoint ramp when the Process Variable is unable to keep up with the changing
setpoint. This is selected by:-
Name Description Range Status
SPrr
SP Rate Limit. To set the rate at which the setpoint changes
OFF (0)
No setpoint rate limit
Value
Setpoint rate of change is limited to this value
SPrSrc
Modbus address of the parameter supplying the value of SPrr -1 means it is not wired
Hbty
Sets the holdback strategy for setpoint ramps
OFF (0)
No holdback
Lo (1)
Setpoint ramp is held back when the PV is below the Setpoint by the Holdback value
Hi (2)
Setpoint ramp is held back when the PV is above the Setpoint by the Holdback value
bAnd (3)
Setpoint ramp is held back when the PV is below or above the Setpoint by the Holdback value
SRLHb
The SP ramp is currently:-
OFF (0)
ramping
HbAc (1)
on Hold
SRLHd
SP Rate Limit Hold. Stops the SP ramp
no (0)
enabled
YES (1)
on Hold
SRLAct
SP Rate Limit Active Status.
no (0) no Setpoint rate limit not active
YES (1) Yes Ramping
SRLStA
SP Rate Limit Complete Flag. SP ramp has
no (0) no NOT reached the Target SP
YES (1) Yes reached the Target SP
SRLDis
Disable SP Rate Limit. Select from:-
no (0) no Setpoint rate limit enabled
YES (1) Yes Setpoint rate limit disabled
Hbkdis
Disable Holdback. Select from:-
no (0) no Holdback enabled
YES (1) Yes Holdback disabled
StkHbk
Sticky Holdback Status. As the above flag could be set and reset very frequently as
the PV tries to follow the SP, a second output - Sticky Holdback Status - is provided.
This will remain permanently on if the PV is achieving at least half the rate of the
setpoint. This output is used to give a consistent message over communications to
show that Holdback has very recently been active
Page 60
2500 Controller Engineering Handbook
58 Part No HA027115 Issue 4.0 Mar -11
4.6.3. Remote Setpoint Parameters
These parameters are also in the Control → LOOP0x → L0x_SP list.
Name Description Range Status
rm_SP
Remote Setpoint. A setpoint can be wired from a remote source to replace the local
setpoint
rm_Src
Remote Setpoint Source. The source from which the remote setpoint is wired
L-r
Remote Setpoint Enable. Allows the ‘Remote’ setpoint to replace the Internal setpoint,
or to act as a trim to the Internal Setpoint. Alternatively the Internal Setpoint can trim
the Remote Setpoint. This is selected using the ‘Remote Setpoint Configuration’ in
the Loop SP Configuration List.
no (0) no SP1 or SP2 is being used by the PID
YES (1) Yes The remote setpoint is being used by the PID
L-rSrc
Remote Setpoint Enable Source. The source from which the remote setpoint enable is
wired
4.6.4. Control Setpoint – Ramp Parameters
These parameters are also in the Control → LOOP0x → L0x_SP list.
They are used to synchronise ramp segments over a number of 2500 controllers, using communications.
Name Description Range Status
NwTrSP
Next Slave Instrument Target Setpoint. The next setpoint to be loaded into the Rate
Limit block
NwRmRt
Next Slave Instrument Ramp Rate. The next rate limit to be loaded into the Rate Limit
block
SISync
Trigger New Ramp. Load the next values into the ramp block
no (0) no New Ramp not triggered
YES (1) Yes New Ramp triggered
The following parameters may be hidden if not required for the operation of the instrument. To reveal uncheck the ‘Hide
Parameters’ box in ‘Options → Parameter Availability Settings’
Loct
Local Setpoint Trim. A fixed ‘offset’ value applied to the working setpoint
LocL
Local Setpoint Trim Low Limit. To set a high limit on the setpoint trim value
LocH
Local Setpoint Trim High Limit. To set a low limit on the setpoint trim value
Hb
SP Rate Limit Holdback Value. Sets the allowed error, in Engineering Units, between
SP and PV before Holdback is invoked. Not available if SP Rate Limit Holdback Type =
OFF. There is a separate Disable Holdback input
Page 61
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 59
4.7. LOOP SETPOINT CONFIGURATION
These parameters set up or configure the way in which the loop setpoints are designed to operate.
Figure 4-11: Loop Setpoint Configuration
4.7.1. Setpoint Function Block
The schematic diagram below shows how the setpoints are connected and selected and where the setpoint
limits are applied.
Figure 4-12: Setpoint Function Block Schematic
The Remote Setpoint Configuration is in the Setpoint Configuration List (Control → LOOP0x → L0xSPC) and can
only be changed in Configuration Mode. The other parameters appear in the Setpoint Parameter List (L0x_SP).
This list will change depending on the Remote Setpoint Configuration selected.
The Target setpoint is then fed to a ramp block that applies a Rate Limit to setpoint of the PID. There is a rate
limit enable/disable input.
Figure 4-13: Setpoint Rate Limit Schematic
Rate limit units are selected in Setpoint Configuration List.
Rate
Limit
Working SP
Target SP
Range Max
L01CFG.rnGH
Range Min
L01CFG.rnGL
Hold/Resume
Rate Units
/sec, /min,
/hour
SP Rate Limit Complete flag
SP Rate Limit Active Status
Target SP
Range Max
Lo1CFG.rnGL
Range Min
L01.rnGL
Remote SP
SP2
SP1
SP1 High Limit
SP1 Low Limit
SP2
SP1
SP2 High Limit
SP2 Low Limit
+
Local SP Trim
Remote
Local
Local Trim High
Local Trim Low
Local SP + RemoteTrim
Loc.t
Remote only SP
+
Remote SP Enable
Remote +
Local Trim
rmt.t
Internal SP Select
Remote SP Configuration
In Configuration mode only!
Page 62
2500 Controller Engineering Handbook
60 Part No HA027115 Issue 4.0 Mar -11
4.7.2. Setpoint Configuration Parameters
These parameters are in the Control → LOOP0x → L0xSPC list.
Name Description Range Status
rmTr
Remote Tracking. Defines the local setpoint behaviour when changing from Remote
to Local setpoint. Read only in Operator Mode.
OFF (0) Off Active Local setpoint will remain unchanged
trAc (1) Track Active local setpoint will track the value of the remote setpoint
mTr
Manual Track. Defines what the active local setpoint does in Manual Mode. Read only
in Operator Mode
OFF (0) Off Local setpoint will remain unchanged
trAc (1) Track Local setpoint will track the value of the process variable (servo)
rmPU
Rate Limit Units. Sets the rate units – Operator or Configuration Modes
PSEc (0) Per second
Pmin (1) Per Minute
PHr (2) Per hour
rmt
Remote Setpoint Configuration. In remote mode the working setpoint is modified by:-
none (0)
SP (1) Remote Setpoint
Loc.t (2) Remote Setpoint + local trim
rmt.t (4)
Remote trim + local setpoint
PVOnSc
WSP to PV On Slave Sync Signal. Used by an external master to servo the working
setpoint to the process variable
no (0) No No sync
YES (1) Yes Sync WSP to PV
StLR
Startup Local/Remote Mode. Defines the Setpoint Mode when the controller
powers up
NoChang
(0)
No Change Setpoint selection remains as it was when the controller powers down
Local (1) Local Controller takes the local Setpoint when it powers up
Remote (2) Remote Controller takes the Remote Setpoint when it powers up
StWSP
Startup WSP Mode. Defines the setpoint strategy when the controller powers up
NoChang
(0)
No Change The setpoint remains the same as when the controller was last used
GotoPV (1) Goto PV The setpoint takes the same value as the process value
Go TSP (2) Goto TSP The setpoint takes the value of the Target setpoint
StHld
Startup Hold Mode . Defines the HOLD strategy when the controller powers up
NoChang
(0)
No Change Hold remains the same as it was when the controller was last used
Hold (1) Hold The controller powers up in HOLD
NoHold (2) NoHold The controller powers up in the normal ramp mode NOT in Hold
Page 63
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 61
4.8. CONTROL OUTPUT
4.8.1. Output Function Block
This block diagram shows how the parameters and limits are used on the Output of a PID block.
Figure 4-14: PID Output Schematic
4.8.2. Output Parameters
Figure 4-15: Output Parameters
These parameters are in the Control → LOOP0x → L0x_OP list.
Name Description Range Status
Ch1OP
Ch1 Output. The current value of channel 1 output
¦%
Ch2OP
Ch2 Output. The current value of channel 2 output
¦%
OPLo
Low Power Limit. Limits the minimum output demand (0 to 100%)
¦%
OPHi
High Power Limit. Limits the maximum output demand (0 to 100%)
¦%
rOL
Remote Low Power Limit. Limits the minimum remote output demand (-100 to 100%)
¦%
rOLSrc
Remote Low Power Limit Source. Low demand limit can be wired to a parameter
rOH
Remote High Power Limit. Limits the maximum remote output demand (-100 to 100%)
¦%
rOHSrc
Remote High Power Limit Source. High demand limit can be wired to a parameter
ORL
Output Rate Limit Enable. Enables the OPrr value to limit the rate of change of the
Output.
OFF (0)
Off The Output ramp rate is not limited.
on (1)
On Enabled. The Output ramp rate will be limited by the OPrr value.
ORLSrc
Output Rate Limit Enable Source. Modbus address of the parameter used as the Output
Ramp Limit Enable. –1 means not wired.
Auto
Manual
OP High Limit
OP Low Limit
OP Rate Limit
WOP
Ch 1 OP
Ch 2 OP
Dual OP
Cool Gain
>0.0
<0.0
Track
En
Track IP
Manual
Tar
g
et
OP
PID Block
Output
Page 64
2500 Controller Engineering Handbook
62 Part No HA027115 Issue 4.0 Mar -11
Name Description Range Status
OPrr
Output Rate Limit. Sets the rate of change in output demand in seconds
OPrSrc
Output Rate Limit Source. Modbus address of the parameter used as the Output Rate
Limit. –1 means not wired.
ont1
Ch1 Output Minimum On Time. Limits the switching rate of a relay or logic output
oSbOP
Sensor Break Power. Sets the demand output level in % in the event of the controlled
variable being out of range
¦%
TkEn
Output Track Enable. A feedback signal from the output is used for integral desaturation. This signal may be derived internally or from an external source.
no (0)
No Not enabled. The default internal OP is used for the integral calculation.
YES (1)
Yes Enabled. The feedback signal is forced to a remote output feedback
TkESrc
Output Track Enable Source. The Output Track Enable Source allows an external
source of output to stop integral wind up in some applications such as cascade control.
The integral will calculate a PID output to match the external value when manual to auto
bumpless transfer is activated.
TrkIP
Track Input. The input value that the Output tracks when
Control → LOOP0n → L0n_OP → TkEn is set to Track Enable
Normally a feedback signal from the output used for integral de-saturation.
TrkSrc
Track Input Source. Modbus address of the parameter whose value is used as the
Track input
-1 means it is not wired
PFFVal Power Feed Forward. Monitors the demand supply to the controller and adjusts the
output demand to compensate for changes in the supply. This parameter shows the
current value of the power feed forward
PFFSrc Power Feed Forward Source. Provides a wireable source for the power feed forward
measurement
The following parameters may be hidden if not required for the operation of the instrument. To reveal uncheck the ‘Hide
Parameters’ box in ‘Options → Parameter Availability Settings’
FOP
Forced Output Level Power level on transferring to Manual if the Forced Output Mode is
selected in Control → LOOP01 → L01CFG → FOP
hYS1
Hysteresis 1 Only available if Control Type set to OnOff in Control → LOOP0x → L0xCFG
list. Channel 1 On Off Control \n0\tNo hysteresis or gap between output going OFF or
coming ON\n>0\tGap in engineering units between the output going OFF and coming
ON
OFF (0) Auto The cutback value is set by the PID Block
Value The hysteresis value is entered manually
hYS2
Hysteresis 2
OFF (0) Auto The cutback value is set by the PID Block
Value The hysteresis value is entered manually
ont2
Ch2 Output Minimum On Time. Limits the switching rate of a relay or logic output
oSbOP
Sensor Break Power Power applied in ON/OFF control when the sensor is detected as
broken
-100 (0)
Channel 2 fully ON
0 (1)
Both Channels OFF
100 (2)
Channel 1 fully ON
TkEn
OP Track Enable The integral is adjusted to make output track the TrkIP parameter in the
L0x_OP folder
no (0) No tracking disabled
YES (1)
Yes Output is made equal to the Track Input
TkESrc
OP Track Enable Source Modbus address of the flag used to enable Output Track mode
-1 means it is not wired
AbPwrL
Absolute Low Power Limit Internal R/O parameter
Page 65
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 63
4.8.3. Valve Control Outputs
There are two types available Bounded or Boundless Mode. Bounded requires feedback from a potentiometer
giving valve position. Boundless (sometimes known as Velocity or Unbounded mode) does not require position
feedback.
Figure 4-16: Valve output Parameters
4.8.4. Valve Control Parameters
These parameters are in the Control → LOOP0x → L0xMTR list. This list only appears if ‘Control Type’ (L0xCFG
List) is set to a valve position output.
Name Description Range Status
tm Valve Travel Time. Set to the time it takes for the valve to go from fully closed to fully
open.
Int
Valve Inertia Time. Set this time to the time that the motor carries on moving after
the signal has ended.
bAct Valve Backlash Time. Set to compensate for any backlash in linkages
mPt Minimum Pulse Time. Sets the minimum on time of the device (normally a relay) which
switches the motor
PotHi Valve Positioner High Limit. Set to the required output value with the valve at the high
position.
¦%
PotLo Valve Positioner Low Limit. Set to the required output value with the valve at the low
position.
¦%
Sensor break action options are different for Velocity Mode (Boundless) and Position Mode.
Vbr
Boundless Sensor Break Action.
rESt (0)
Rest remain in existing position
uP (1)
Up drive valve fully open
dwn (2)
Down drive valve fully closed
SbOP
Bounded Sensor Break Action. Set the value (in %) that the valve must move to in the
event of sensor break.
VP_OP
VP Manual Output. Output demand value when in manual. In manual set to 1 to
raise or 2 to lower
- operates for 1 minimum pulse length
¦%
PPos Pot Position. Indicates the position of the valve from the feedback potentiometer.
¦%
PPoSrc
Pot Position Source. Modbus address of the parameter supplying the value of the pot
position.
-1 means it is not wired
CalPot
Pot Input Calibration Enable.
OFF (0)
Off Pot calibration disabled.
on (1)
On Pot calibration enabled.
Page 66
2500 Controller Engineering Handbook
64 Part No HA027115 Issue 4.0 Mar -11
4.9. RATIO CONTROL
Ratio Control is a technique used to control a process variable at a setpoint which is calculated as a proportion
of a second (lead) input. The ratio setpoint determines the proportion of the lead value that is to be used as the
actual control setpoint. The ratio setpoint can be applied as either a multiplier or as a divisor to the second
input.
A typical application is in gas fired furnaces where in order to achieve efficient combustion, the gas and air flow
supplied to the burners needs to be maintained at a constant ratio.
4.9.1. Basic Ratio Control
Each loop in the 2500 contains a ratio control function block. Figure 4-17shows a block diagram of a simple
ratio controller. The lead PV is multiplied or divided by the ratio setpoint to calculate the desired control
setpoint. Prior to the setpoint calculation, the ratio setpoint can be offset by the ratio trim value and must obey
the overall ratio setpoint operating limits.
Figure 4-17: Ratio Control Schematics
4.9.2. Ratio Parameters
Ratio control is selected by ‘Loop Type’ = ‘Ratio’. This parameter is found in Control → LOOP0x → L0xCFG.
Figure 4-18: Ratio Control Parameter List
Main Control Loo
p
Main PV Process
Lead P
V
Multipl
y
Or
Divide
Ratio SP
Ratio Trim
Ratio SP Limits
Ratio Trim
Control OP
Local Trim
Range Hi
Range Lo
+
+
Page 67
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 65
Ratio parameters are found in Control → LOOP0x → L0xRAT
Name Description Range Status
SP
SP Setpoint generated by the ratio calculation in engineering units
¦9
MRatio
Measured Ratio Continuous calculation of the actual measured ratio. It is calculated
from the Lead PV and the Process PV.
¦9
WRatSP
Working Ratio SP. The actual Ratio being using by the algorithm after limits and trim.
¦9
RAType
Ratio Type Defines how the ratio is calculated. Can only be set in configuration
level.
Divide (0)
Divide Divides the lead PV by the working ratio setpoint
Mult (1)
Multiply Multiplies the lead PV by the working ratio setpoint
RAL
Ratio Setpoint Low Limit Minimum range limit for the ratio setpoint
¦%
RAH
Ratio Setpoint High Limit Maximum range limit for the ratio setpoint
¦%
RatSrc
Ratio Setpoint Source. The modbus address of the parameter used for the ratio
setpoint
-1 means NOT wired
Rat_SP
Ratio Setpoint Adjustment of the ratio setpoint value.
¦%
TriSrc
Ratio Trim Source. Modbus address of parameter used for the Ratio Trim SP
-1 means it is NOT wired
Trim
Ratio Trim Adjustment of the ratio trim value.
¦%
LeaSrc
Lead PV source. Modbus address of parameter used for the Lead PV
-1 means it is NOT wired
LeadPV
Lead PV The measured parameter used to ratio the process variable.
¦9
REn
Ratio Enable Ratio control may be switched off, eg, during commissioning
OFF (0)
Off Ratio is not used – PID uses the local setpoint only. The parameter ‘Ratio Valid’ will show YES.
on (1)
On Ratio is calculated and used. The parameter ‘Ratio Valid’ will show no.
REnSrc
Ratio Enable source. Modbus address of parameter used for the Ratio Enable. -1
means it is NOT wired
RatTrk
Ratio Track Mode Defines the ratio tracking strategy. Can only be set in configuration
level.
OFF (0)
OFF Ratio track is disabled
on (1)
ON whenever ‘Ratio Enable’ is set to ‘Off’ the Ratio SP will track the measured ratio. This feature allows
the user to set the Ratio SP according to the current condition of the process.
RatVld
Ratio Valid.
no (0)
Ratio is valid or disabled
YES (1)
Ratio is enabled and no sensor break
Page 68
2500 Controller Engineering Handbook
66 Part No HA027115 Issue 4.0 Mar -11
4.10. CASCADE
4.10.1. Overview
Cascade control is classified as an advanced control technique used, for example, to enable processes with long
time constants to be controlled with the fastest possible response to process disturbances, including setpoint
changes, whilst still minimising the potential for overshoot. It is a combination of two PID controllers, where the
output signal from one (the master) forms the setpoint for the other (the slave). For cascade control to be
effective the slave loop should be more responsive than the master.
4.10.2. Trim Mode
The 2500 controller uses trim mode cascade control an example of which is shown in Figure 4-19. The slave
controls the temperature in a furnace. The master is measuring the temperature of the workpiece and
controlling the setpoint of the slave. In this case the master trims the setpoint of the slave rather than controlling
it directly. By limiting the amount of trim the temperature of the furnace will remain within bounds.
Feedforward allows either the master PV, master SP or a user defined variable (FF_Src) to be fed forward so that
it directly influences the slave setpoint.
A typical application for SP feedforward could be in a heat treatment furnace, where it can be used to extend
the life of heating elements by limiting their maximum operating temperature.
An application using PV feedforward could be in autoclaves or reactor vessels where it is sometimes required to
protect the product from excessive temperature gradients (also referred to as Delta T Control). The effect of this
is to limit the furnace temperature to a band around the target temperature.
Feedforward can also be a user defined variable in trim mode in the same way as full scale mode
Figure 4-19: Cascade Trim Control
4.10.3. Auto/Manual Operation in Cascade
Auto/Manual operates on both master and slave loops.
When the controller is placed in manual the slave working setpoint will track the value of the slave process value
continually, therefore ensuring bumpless transfer.
When cascade is deactivated the master loop will monitor the setpoint of the slave loop and provide a smooth
transition of output demand when the loop moves back to cascade mode.
4.10.4. Cascade Controller Block Diagram
Figure 4-20: Cascade Controller in Trim Mode
In the ‘L01CFG’ Parameter list ‘Feedforward Type’ must be set to ‘FEEd’ and the ‘Remote Feedforward’ input
value is displayed in ‘L01PID’.
PV
Feedforward
Tem
p
SP
Load Temperature
Furnace
Master
Controller
Slave
Controller
SP Feedforward
PID OP
SP
Heatin
g
Element
PID OP
Furnace Temperature
Trim
+
+
SP Feedforward or
PV Feedforward
may be selected
Feedforward Type
Master WSP
SlvHR
FF_SP
Slave LSP
Master OP
Slave SP
+
in1
*(AuxHR-AuxLR)/100
Master PV
SP Limit
Scale to Slave PV units
SlvLR
Trim Limit
User wire
Re-scale to 0%
Master FB
+
+
-
FF_SP
in2
*100/(AuxHR-AuxLR)
in1
in
2 (In1
*-LR)*(AuxHR-AuxLR)
/
(HR-LR)+AuxLR
Page 69
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 67
4.10.5. Cascade Parameters
Cascade control is selected by the LoopType = Cascade .
Figure 4-21: Cascade Control Parameter List
Cascade parameters are found in Control → LOOP0x → L0xCAS.
Name Description Range Status
CasM
Cascade Mode. Selected Cascade Mode
Full (0)
Full scale Cascade mode
Full FF (1)
Full scale feed forward mode
SP.FF (2)
Setpoint feed forward mode
PV.FF (3)
PV feed forward mode
TrHi
Cascade Feedforward Trim High Limit. The external analogue input being used as high
limit for the PID contribution in Feedforward or the Cascade feedforward using remote
input
¦9
TrHiSrc
Cascade Feedforward Trim High Limit source Modbus address of parameter used as
the cascade Feed Forward Trim High Limit. -1 means it is NOT wired
TrLo
Cascade Feedforward Trim Low Limit. The external analogue input being used as low
limit for the PID contribution in Feedforward or the Cascade feedforward using remote
input
¦9
TrLoSrc
Cascade Feedforward Trim Low Limit source Modbus address of parameter used as the
cascade Feed Forward Trim Low Limit. -1 means it is NOT wired
FF_Src
Cascade Feedforward Value Source. Modbus address of parameter used as the
cascade Feed Forward
-1 means it is NOT wired
FF_SP
Cascade Feedforward Value. The external analogue input being used for feedforward
in the same eng units as PV
¦9
DisSrc
Disable Cascade Source. Modbus address of flag used to disable cascade. -1 means it
is NOT wired
DisCas
Disable Cascade. It is sometimes useful to disable cascade when starting the process.
This parameter provides a simple way to do this, particularly if it is wired using DisSrc.
When disabled the auxiliary loop is turned off and the controller returns to single loop
mode using the local setpoint
no (0)
The cascade loops are both active
YES (1)
Only the slave loop is active
WkFFSP
Cascade Working Feedforward Value. The working feed forward value after trim and
limit.
¦9
MFB
Master Feedback Value. Cascade master PID feedback value.
¦9
Page 70
2500 Controller Engineering Handbook
68 Part No HA027115 Issue 4.0 Mar -11
Name Description Range Status
The following parameters may be hidden if not required for the operation of the instrument. To reveal uncheck the ‘Hide
Parameters’ box in ‘Options → Parameter Availability Settings’
SlvHR
High Range of Slave Loop. Maximum value of the PV of the auxiliary loop
¦9
SlvLR
Low Range of Slave Loop. Minimum value of the PV of the auxiliary loop
¦9
4.10.5.1. Auxiliary Loop
Note in the Browser section in Figure 4-21 there are folders for the Auxiliary loop:
L1APID PID parameters
L1ASET PID parameters Sets
L01AUX Loop set up
L1A_OP Loop output set up.
The master loop has to be configured in a similar manner to the slave loop. This is done in the same way as the
main (slave) loop, though there are fewer parameters in each list.
Page 71
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 69
4.11. OVERRIDE
Overview
Override Control allows a secondary control loop to override the main control output in order to prevent an
undesirable operating condition. The override function can be configured to operate either in minimum,
maximum or select mode.
A typical example can be implemented in a heat treatment furnace with one thermocouple attached to the
workpiece, and another situated close to the heating elements. Control of the furnace during the heating up
period is regulated by the override (heating element) temperature controller which provides a safeguard
against overheating. Control of the furnace will switch over to the workpiece temperature controller at some
point when the temperature is near to its target setpoint. The exact point of switchover is determined
automatically by the controller, and will be dependent on the selected PID terms.
Simple Override
Override control is available with analogue, time proportioning and ON/OFF control outputs. It is not available
with valve position outputs. Figure 4-22 shows a simple override control loop. The main and override
controller outputs are fed to a low signal selector. The override controller setpoint is set to a value somewhere
above the normal operating setpoint, but below any safety interlocks.
There is only one Auto Manual switch for both loops. In manual mode the control outputs of both loops track
the actual output, ensuring bumpless transfer when auto is selected. The transfer between main and override
PID control is also bumpless.
Figure 4-22: Override Control Schematic
Min select
Main Control Loo
p
PID only
Override
Control Loop
PID or
On/Off
Control
Output
Main OP
Override OP
Override SP
+ Override Trim
Main SP
Main PV
Override PV
‘Auxiliary’ Loo
p
Override Type
Page 72
2500 Controller Engineering Handbook
70 Part No HA027115 Issue 4.0 Mar -11
4.11.1. Override Parameters
Override is configured by setting L0xCFG → Loop Type to Override.
Figure 4-23: Override Control Parameter List
Override parameters are found in Control → LOOP0x → L0xOVR.
Name Description Range Status
OvrTyp
Override Type. Override Type
Defines the strategy for Override Control
MinOP(0)
The working output demand is the minimum of the Main and Aux output demands
MaxOP(1)
The working output demand is the maximum of the Main and Aux output demands
Select(2)
Select which loop is active using Control → LOOP0x → L0xOVR → ActLP
OvrSrc
Disable override source. Modbus address of flag used to disable the override control
-1 means NOT wired
OvrDis
Disable override. It is sometimes useful to disable override when starting the process.
This parameter provides a simple way to do this, particularly if it is wired using OvrSrc.
When disabled the controller returns to single loop mode using the local setpoint
no (0)
no Both Main and Auxilliary loops are active
YES (1)
YES Only the main loop is active
ActSrc
Active loop source. Modbus address of parameter used to SELECT active loop
-1 means it is NOT wired
ActLP
Active Loop. Indicates which loop is currently controlling the process or can be set if
Control.LOOP0x → L0xOVR → OvrTyp is set to SELECT
Main (0)
The main loop is active
Aux (1)
The auxiliary loop is active
TriSrc
Override Loop SP Trim source. Modbus address of parameter used as the Override SP
Trim
-1 means it is NOT wired
Trim
Override Loop SP Trim. SP trim for the Override auxiliary loop
¦9
Page 73
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 71
4.12. TUNING
In tuning, you match the characteristics of the controller to those of the process being controlled in order to
obtain good control. Good control means:
• Stable, ‘straight-line’ control of the PV at setpoint without fluctuation
• No overshoot, or undershoot, of the PV setpoint
• Quick response to deviations from the setpoint caused by external disturbances, thereby rapidly restoring
the PV to the setpoint value.
Tuning involves calculating and setting the value of the parameters listed in Control → L0xPID list. This may be
done manually or automatically. The following section describes automatic tuning.
4.13. AUTOMATIC (ONE-SHOT) TUNING
The ‘one-shot’ tuner works by switching the output on and off to induce an oscillation in the measured value.
From the amplitude and period of the oscillation, it calculates the tuning parameter values.
If the process cannot tolerate full heating or cooling being applied during tuning, then the levels can be
restricted by setting the ‘Autotune High Power Limit’ (TnOH) and ‘Autotune Low Power Limit’ (TnOL). These
limits are only applied during the autotune process. However, the measured value
must
oscillate to some
degree for the tuner to be able to calculate values.
Under normal control the output power limits may be set by ‘Low Power Limit’ and ‘High Power Limit’ found in
Control → L0x_OP list. If these limits are set to a lower value than the autotune limits, then the autotune high
and low power limits will be clipped to the output limits as soon as Autotune is run.
A One-shot Tune can be performed at any time, but normally it is performed only once during the initial
commissioning of the process. However, if the process under control subsequently becomes unstable (because
its characteristics have changed), you can re-tune again for the new conditions.
It is best to start tuning with the process at ambient conditions and with the SP close to the normal operating
level. This allows the tuner to calculate more accurately the low cutback and high cutback values which restrict
the amount of overshoot, or undershoot.
4.13.1. Autotune Parameters
In the 2500 Loops do not have their own individual Autotune. There is a single tuning block available to be
used on the loops one at a time. There is no configuration required.
Figure 4-24: Auto Tune Parameter List
Autotune parameters are found in Control → ATUN list.
Name Description Range Status
tuning
Tuning Active. Set if the tuning block is active.
Note that there is only 1 tuning block which has to be used to tune the internal loops
one by one, using Control → ATUN → TnLpNr
OFF (0)
Tuning Inactive
on (1)
Tuning in progress
TnOL
Auto tune low power limit. Set this to limit the minimum output demand level which the
controller will supply during the tuning process. If the low output power limit set in the
output list is higher the autotune low limit will be clipped to this value
¦%
Page 74
2500 Controller Engineering Handbook
72 Part No HA027115 Issue 4.0 Mar -11
Name Description Range Status
TnOH
Auto tune high power limit. Set this to limit the maximum output demand level which
the controller will supply during the tuning process. If the high output power limit set in
the output list is lower the autotune high limit will be clipped to this value
¦%
TnStat
Tuning State. Reports the state of the individual PID loop tuning
OFF (0)
Not tuning
Noise (1)
Monitoring noise
Init (2)
Initialising
Start (3)
Start tune at current setpoint
Start (4)
Start tune at new setpoint
NewSP (5)
Tune to new setpoint
Min (6)
Find minimum
Max (7)
Find maximum
Store (8)
Store zero time
Zero (9)
Set output to zero
Calc (10)
Calculating PID values
Abort (11)
Tuning aborted
DONE (12)
Tuning complete
CTStat
CascadeTuning State. Reports the state of tuning a cascade loop. The auxiliary loop is
tuned first followed by the main
OFF (0)
Not tuning
Init (1)
Initialising the auxiliary loop
Aux PID (2)
Tuning the auxiliary loop
Wait (3)
Wait
Wait2 (4)
Wait again
Init (5)
Initialising the main loop
PID1 (6)
Tuning main PID
TnOP
Actual output demand that the tuner is requesting ¦%
TnLpNr
Tune Loop Number. Choose the required loop. Autotune starts when the loop is
chosen
OFF (0)
Not tuning
L01PID(11)
Tune loop 1
L1APID(12)
Tune auxiliary loop 1
L1CASC(13)
Tune cascade loop 1
The above three parameters are repeated for as many loops as supplied up to a maximum of eight. Add ‘10’ to the
enumerated values shown above for each loop. For example L02PID has the value (21) and so on.
TnPID
Tune PID Number. Reports which loop is being tuned
OFF (0)
Tuning inactive
L01PID (1)
Tuning loop 1
L1APID (2)
Tuning auxiliary loop 1
The above two parameters are repeated for as many loops as supplied up to a maximum of eight. The enumerated values
become (3) and (4) for loop 2 and so on.
TnWSP
Working SP of Current Tune Stage. Actual SP that the tuner is currently using.
¦%
STime
Current Tune Stage Time. The time spent in the current tune stage.
Page 75
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 73
4.13.2. Cascade Tuning
When tuning a cascade loop it is necessary that both master and slave loops are tuned. It is recommended that
each loop is tuned independently using the procedure below.
Because the slave loop is used by the master loop it must be tuned first.
4.13.3. Example: To Tune a Full Scale Cascade Loop
Step 1. Configure the loop as cascade full scale as follows:-
In L0xCNF Set ‘Loop Type’ = Cascade
In L0xCNF Set ‘Feedforward Type’ = FEEd
In L0xCAS Set ‘Disable CSD’ = Yes
In L0x_SP Set ‘Setpoint 1’ = the normal operating setpoint value for the main loop
In L0x_SP Set ‘Local SP’ = the normal operating setpoint value for the slave loop (when
cascade is disabled)
Step 2. Start the controller in Operator Level
Step 3. Set tune output high and low limits as follows:
Note: For the slave tune you may wish to restrict the ability of the tuner to disturb the process. Tune OH
should, therefore, be set to a value that will only enable the tune to achieve the local setpoint which you have
chosen.
In ATUNE Set ‘TnOL’ to a value which will limit the minimum output demand during tuning.
This may be 0.0 for a heat only loop.
Set ‘TnOH’ to a value which will limit the maximum output demand during tuning.
Step 4. Start tune on the slave loop as follows:
In ATUNE Set ‘Tune Loop Number’ to L1APID
Step 5. You may monitor the progress of the tune by viewing the following parameters:
In ATUNE ‘TnStat’ This indicates which step is being performed
‘TnOP’ The output demand of the autotune. For a slave loop this will be the same as the
working output demand.
‘CTStat’ The length of time this particular step has been running. The tune step will abort
after two hours
Step 6. On completion of the slave loop tuning:
Keep the loop in Cascade Disabled, and allow the slave loop to control the process. You must allow the slave
loop to control at its Local SP. Wait for the master loop to settle to a steady state value. (Note, it is unlikely
that the master loop steady state is the same as the slaves).
When the master PV is at a steady value proceed with tuning the master loop. (Note, if the master loop has
not settled satisfactorily you may not be able to tune the master loop at all, since it is necessary to restrict the
disturbance of the slave when tuning the master.
Step 7. Tune the master loop
In ATUNE Set ‘TnOL’ and ‘TnOH’
The values chosen should be symmetrical and chosen such that the slave stays in control
(typically +
0.5 * slave proportional band).
This amount, however, may not be sufficient to disturb the master to achieve a successful tune.
If the proportional band of the master is in engineering units, the tune hysteresis of the master
will be +
1 engineering unit. For a temperature loop, therefore, the master must be disturbed
by at least 1 degree.
TnOL and TnOH are set in %. Although it is the master which is being tuned, it is the slave
working SP which has to be modified in order to achieve a change in the output and hence
measure a disturbance in the master PV. Therefore, TnOL and TnOH relate to a percentage of
the slave range by which the slave working SP will be changed.
For example, if the slave has a range of –200 to +1372 the slave range is 1572 and TnOL and
TnOH are 1%, then the slave working setpoint will be modified by + 15.72 degrees.
In ATUNE Set ‘TnLpNr’ to L0xPID
In L0xCAS Set ‘DisCas to ‘No’
This is to re-enable cascade mode and must be done before the time out period of 1 min
Page 76
2500 Controller Engineering Handbook
74 Part No HA027115 Issue 4.0 Mar -11
Step 8: Return to control
The slave and master loops should now be tuned. Try changing the main setpoint and observe the response.
If the master PV response is oscillatory then you may not have restricted the disturbance of the slave enough.
Try decreasing the values of ‘TnOL’ and TnOH’ and retune the master.
To invoke tune select Tune Loop Number to the particular loop that requires to be tuned.
Loop Number Tunes Write Value via Comms
1 L01PID (Slave) 11
1 L1APID (Master) 12
1 L1 Cascade pair 13
2 L02PID (Slave) 21
2 L2APID (Master) 22
2 L2 Cascade pair 23
3 L03PID (Slave) 31
Etc Etc etc
Table 4-1: Tuning via Comms
Setting Tune Loop Number to 0 (OFF) will discontinue tuning.
If the sequence of tuning loops one by one is being handled by a supervisory system over communications,
then the system should monitor the Tuning Active flag and wait for that to reset, or wait until Tune Loop
Number is reset to 0, before setting Tune Loop Number to the value for the next Loop to be tuned.
The remaining parameters give diagnostic information about what the tuning block is doing.
Tuning Cascade Tuning
OFF OFF
Noise Init
Init AuxPID
Start Wait
Start Wait2
NewSP Init
Min PID1
Max
Store
Zero
Calc
DONE
Table 4-2: Auto Tuning States
Page 77
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 75
4.14. LOOP DIAGNOSTICS
Figure 4-25: Loop Diagnostic Parameter List
All these parameters are read only and are mostly of use in diagnosing control problems.
4.14.1. Loop Status Word
The Loop Status Word (and the equivalent for the Auxiliary Loop) is useful for a supervisory system to read and
to display loop status. Each of the 16 bits in the word represents a condition.
Bit Value (Decimal) Bit set
0 1 Hold
1 2 Sensor Break
2 4 SP ramp active
3 8 Remote SP selected
4 16 SP servo
5 32 Debump
6 64 Loop Break
7 128 Integral Hold
8 256 Remote SP fault
9 512 Direct Action
10 1024 Track
11 2048 Power Limit
12 4096 Autotune
13 8192 Adaptive tune
14 16384 Droop Tune
15 32768 Manual
Table 4-3: Loop Status Word
4.15. LOOP ALARMS
Each Loop has 4 alarms which apply to the Loop Process Variable. They may be set to Absolute High, Absolute
Low, Deviation High, Deviation Low, and Deviation band. One of four alarms, Alarm 4, may also be set as a ‘rate
of change’ alarm.
The alarm function blocks have many features. All the alarms in the 2500 use the same function block and are
described in detail in Chapter 5.
Page 78
2500 Controller Engineering Handbook
76 Part No HA027115 Issue 4.0 Mar -11
5. Chapter 5 Alarms
5.1. DEFINITION OF ALARMS AND EVENTS
Alarms are used to set a flag when a pre-set level has been exceeded (an analogue alarm) or an event has
occurred (a digital alarm). The flag may be used to switch an output - usually a relay - to provide interlocking of
the machine or plant or external audio or visual indication of the alarm. Using Toolkit blocks various alarm flags
may be wired to a single relay output using the OR function.
Alternatively the Alarms flag may just be read over communications and the 2500 supervisory system will
annunciate and take the action required.
Additional alarm options are to make the alarm ‘Blocking’ where a pre-condition has to be met before the alarm
is enabled, or ‘Latching’ where the alarm must be acknowledged before the flag is cleared.
Events are just alarms but are generally defined as conditions that occur as part of the normal operation of the
plant, and are required for information or to start the next phase of the process, etc. For the purposes of the
operation of the 2500, alarms and events can be considered the same.
5.2. TYPES OF ANALOGUE ALARM USED IN THE 2500
This section describes graphically the operation of different types of alarm used in the 2500 controller. For
analogue alarms the graphs show measured value plotted against time.
5.2.1. Absolute High
This alarm (AbSHi) occurs when the Process Variable (PV) exceeds a set high level
Figure 5-1: Absolute High Alarm
5.2.2. Absolute Low
This alarm (ABSLo) occurs when the Process Variable (PV) exceeds a set low level
Figure 5-2: Absolute Low Alarm
Time
→
↑
PV
↓
Hysteresis
↑
Alarm
setpoint
Alarm ON
Alarm OFF
Hysteresis is the
difference between
the alarm ON value
and the alarm OFF
value. It is used to
prevent relay chatter.
Alarm ON
Alarm OFF
Time →
↑
PV
↓
Hysteresis
↑
Alarm
setpoint
Page 79
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 77
5.2.3. Deviation High Alarm
This alarm (devHi) occurs when the difference between the process variable and the setpoint is positive by
greater than the alarm setpoint.
Figure 5-3: Deviation High Alarm
5.2.4. Deviation Low Alarm
This alarm (devLo) occurs when the difference between the process variable and the setpoint is negative by
greater than the alarm setpoint.
Figure 5-4: Deviation Low Alarm
5.2.5. Deviation Band
A deviation band alarm (dEvbnd) monitors the process variable and the working setpoint and continuously
compares the difference against the alarm setpoint. If the difference is either negative by less than, or positive
by greater than the alarm setpoint, the alarm state will be active.
Figure 5-5: Deviation Band Alarm
Process
Variable
Alarm
Setpoint
Working
Setpoint
Hysteresis
Time
PV
Alarm ON
Alarm OFF
Process
Variable
Alarm
Setpoint
Working
Setpoint
Time
PV
Alarm ON
Alarm OFF
Hysteresis
Process
Variable
Alarm Setpoint
Working
Setpoint
Time
PV
Alarm Setpoint
Alarm ON
Alarm OFF
Hysteresis
Hysteresis
Page 80
2500 Controller Engineering Handbook
78 Part No HA027115 Issue 4.0 Mar -11
5.2.6. Rate Of Change Alarm
The Process Value falls faster than the alarm setting or rises faster than the alarm setting.
Figure 5-6: Rate of Change Alarm
Notes:
1. The alarm is activated by excessive positive or negative rates of change
2. An alarm is indicated during the period that the actual rate of change is greater than the set rate of change.
3. There may be a small delay before the instrument displays an alarm condition since the instrument requires
several samples. This delay increases if the set value and actual value are close together
4. A hysteresis value of, say, 1 unit per second will prevent the alarm from ‘chattering’ if the rate of change
varies by this amount
Time
→
↑
PV
↓
↑
Hysteresis
Ne
g
ative Rate of
Change set to x
units per min
Actual rate of
change > x
units per min
Alarm On
Alarm Off
Time
→
↑
PV ↓
↑
Hysteresis
Positive Rate
of Change
set to x units
per min
Actual rate of
change > x
units per min
Alarm On
Alarm Off
Page 81
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 79
5.3. TYPES OF DIGITAL ALARM USED IN THE 2500
This table describes the operation of different types of digital alarm used in the 2500 controller.
ITools List Description
IstruE Alarm output set when input is TRUE
ISFALS Alarm output set when input is FALSE
GoTruE Alarm output set when input changes from FALSE to TRUE
GoFALS Alarm output set when input changes from TRUE to FALSE
ChAnGE Alarm output set when input changes state
Table 5-1: Types of Digital Alarm
5.4. BLOCKING ALARMS
A Blocking Alarm only occurs after it has been through a start up phase. It is typically used to prevent alarms
from being indicated until the process has settled to its normal working conditions.
5.4.1. Absolute Low With Blocking
The alarm only occurs after the start up phase when low alarm has first entered a safe state. The next time a low
alarm occurs will cause the alarm to become active.
Figure 5-7: Absolute Low Blocking Alarm
5.4.2. Absolute High Alarm With Blocking
The alarm only occurs after the start up phase when high alarm has first entered a safe state. The next time a
high alarm occurs will cause the alarm to become active.
Figure 5-8: Absolute High Blocking Alarm
Time
→
↑
MV
↓
Hysteresis
↑
Alarm
setpoint
Alarm ON
Alarm OFF
i.e. If the controller is powered up with
PV > ’Hi Alarm SP’ no alarm is indicated.
The PV must reduce below the ‘High
Alarm SP’ and increase again to > ‘Hi
Alarm SP’. The alarm condition will then
be indicated.
If the controller is powered up with PV <
‘Hi Alarm SP’ an alarm is indicated as
soon as PV > ‘Hi Alarm SP’
Alarm ON
Alarm OFF
Time
→
↑
MV
↓
Hysteresis
↑
Alarm
setpoint
Page 82
2500 Controller Engineering Handbook
80 Part No HA027115 Issue 4.0 Mar -11
5.4.3. Deviation Band With Blocking
The alarm only occurs after the start up phase when low deviation alarm has first entered a safe state. The next
time an alarm occurs, whether high band or low band will cause the alarm to become active.
Figure 5-9: Deviation Band Blocking Alarm
5.5. LATCHING ALARMS
The alarm is indicated until it is acknowledged by the user. Acknowledgement of an alarm is by setting the
Alarm acknowledge flag via communications or, using wiring, from a digital input.
To make an alarm latching there are two options, automatic (Auto), or manual (mAn).
1. Automatic Reset. The alarm continues to be active until both the alarm condition is removed AND the alarm
is acknowledged. The acknowledgement can occur BEFORE the alarm condition is removed.
2. Manual Reset. The alarm continues to be active until both the alarm condition is removed AND the alarm is
acknowledged. The acknowledgement can only occur AFTER the alarm condition is removed.
These are shown below for an Absolute High Alarm
5.5.1. Latched Alarm (Absolute High) With Automatic Reset
The alarm is displayed until it is acknowledged
Figure 5-10: Latched Alarm with Automatic Reset
Alarm
On
Process Variable
Alarm
Off
Alarm Setpoint
Working Setpoint
Alarm
Off
Time
PV
Alarm
On
Alarm
Off
Alarm
On
Alarm
Off
Alarm Setpoint
Hysteresis
Hysteresis
Alarm ON
Alarm OFF
Time
→
↑
MV
↓
Hysteresis
↑
Alarm
setpoint
Automatic Reset
Once the alarm has been acknowledged it will
clear when it is no longer true
Alarm Acknowledged
Page 83
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 81
5.5.2. Latched Alarm (Absolute High) With Manual Reset
Figure 5-11: Latched Alarm with Manual Reset
5.6. GROUPS & ALARM STATUS WORD
All the alarms in the 2500 are in groups associated with a PID loop, an I/O channel, or are User defined alarms.
All the alarm active flags and alarm acknowledged flags are also available within a 16 bit Alarm Status Word
‘AlmSW’, in the following standard format.
Bit Value (Decimal) Set when:
0 1 Alarm 1 (or A) active
Alarms can be acknowledged
individually or as a group using the
Group Acknowledge Flag GrpAck.
Note:
Operator → SYSTEM → AckAll
acknowledges all alarms on the
base.
1 2 Alarm 1 (or A) acknowledged
2 4 Alarm 2 (or B) active
3 8 Alarm 2 (or B) acknowledged
4 16 Alarm 3 (or C) active
5 32 Alarm 3 (or C) acknowledged
6 64 Alarm 4 (or D) active
7 128 Alarm 4 (or D) acknowledged
8 256 Alarm E active
9 512 Alarm E acknowledged
10 1024 Alarm F active
11 2048 Alarm F acknowledged
12 4096 Alarm G active
13 8192 Alarm G acknowledged
14 16384 Alarm H active
15 32768 Alarm H acknowledged
Table 5-2: Alarm Status Word
5.7. LOOP ALARMS
Every PID block in the 2500 includes a group of four alarms. All alarms use the PID block Process Variable as
the alarm input and deviation alarms are with respect to the PID block setpoint.
Figure 5-12: Loop alarms (Configuration mode)
Acknowledging here will not reset the alarm
because it is still in an alarm condition
Alarm ON
Alarm OFF
Time
→
↑
MV
↓
Hysteresis
↑
Alarm
setpoint
Alarm Acknowledged
The alarm must first clear
before it can be reset.
Page 84
2500 Controller Engineering Handbook
82 Part No HA027115 Issue 4.0 Mar -11
5.7.1. Alarm Parameters
These are found in Control → LOOP0x → L0xALM
Name Description Range Status
GrpAck
Group Acknowledge. To acknowledge all
alarms associated with this loop. The action
which follows depends on the type of latching configured, see section 5.5.
no (0)
No Unacknowledged
YES (1) Yes Select to acknowledge
AL_1
Alarm 1 Type. In configuration mode the four alarms may be set to any of the types
listed below: (See also section 5.2)
None (0)
Alarm not configured
AbsLo (1)
Absolute Low
AbSHi (2)
Absolute High
dEvbnd (16)
Deviation Band
devHi (17)
Deviation High
devLo (18)
Deviation Low
rAtE (64)
Rate of Change Alarm 4 only
SP_1
Alarm 1 Setpoint. To set the level at which the alarm operates
¦9
HY_1
Alarm 1 hysteresis. Hysteresis is the difference between the point at which the alarm
switches ON and the point at which it switches OFF.
It is used to prevent relay chatter.
¦9
Ih1
Alarm 1 inhibit. Inhibit prevents the alarm from being indicated. It can be wired to a
source (such as a digital input) or if not wired can be set by the operator.
no (0)
No Not inhibited
YES (1) Yes Inhibited
Ih1Src
Alarm 1 inhibit source. Allows In1 to be wired
bLoc_1
Alarm 1 blocking. In configuration mode the four alarms may be set to blocking, see
section 5.4.
no (0)
No blocking
YES (1)
Blocking
Ltch_1
Alarm 1 latching. In configuration mode the four alarms may be set to latching, see
section 5.5.
no (0)
No latching
Auto (1)
Automatic reset
mAn (2)
Manual reset
Ack_1
Alarm 1 acknowledge. To acknowledge alarm 1. The action which follows depends
on the type of latching configured, see section 5.5.
no (0)
Unacknowledged
YES (1)
Acknowledged
OP_1
Alarm 1 output state.
OFF (0)
Alarm 1 off
on (1)
Alarm 1 on
RtUnit
Alarm 4 rate units Alarm 4 only
SEc (0)
Seconds
min (1)
Minutes
AlmSW
Alarm Status Word See Table 5-2
The above alarms are repeated for alarms 2 to 4.
Page 85
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 83
5.8. USER ALARMS
The 2500 has four unassigned analogue alarms and four unassigned digital alarms.
Figure 5-13: Analogue User Alarm (Configuration Level)
5.8.1. User Alarm Parameters – Analogue
These are found in User_Alarms → AN_ALM
Name Description Range Status
P1A
Alarm 1 Input A Value. To set the analogue value of alarm 1to input A
¦9
P1ASrc
Alarm 1 Input A Source. Allows P1A to be wired
P1B
Alarm 1 Input B Value. To set the analogue value of alarm 1to input A
¦9
P1BSrc
Alarm 1 Input B Source. Allows P1A to be wired
The remaining parameters are the same as the loop alarms
Note:
1. The inputs to the alarm block are unassigned so Input A must be wired to the Value to be tested for the
alarm condition (PV), and for deviation alarms Input B must be wired to the Value used compare with Value
A for alarm condition (SP).
5.8.2. User Alarm Parameters – Digital
The input has to be wired to the Flag to be tested for the alarm condition. In configuration mode all four alarms
may be set to any of the digital alarm types listed in section 5.3.
These are found in User_Alarms → DIGALM
Name Description Range Status
P1
Alarm 1 Input Value. To set the value to alarm 1 input
P1Src
Alarm 1 Input Source. Allows P1 to be wired
AL_1
Alarm 1 Type. In configuration mode the four alarms may
be set to any of the types listed below: (See also section 5.2)
None (83)
Alarm not configured
IStrue (84)
Alarm output set when input is TRUE
ISFALS (85)
Alarm output set when input is FALSE
Gotrue (86)
Alarm output set when input changes from FALSE to TRUE
GoFALS (87)
Alarm output set when input changes from TRUE to FALSE
ChAnGE
Alarm output set when input changes state
The remaining parameters are the same as the loop alarms
Page 86
2500 Controller Engineering Handbook
84 Part No HA027115 Issue 4.0 Mar -11
5.9. I/O ALARMS
Each I/O module has 8 alarms (designated A to H) which are shared between the channels of the module. This
sharing has a default setting but, in configuration mode, individual alarms may be reassigned to other channels.
Figure 5-14: I/O Alarms (Configuration Level)
5.9.1. I/O Alarm Parameters
These are found in IO → Module 0x → MOD0x and are essentially the same as Loop Alarms except that there is
no Group Alarm Acknowledge. Plus:-
Name Description Range Status
ChnSel
Channel select for alarm A.
C1 (1)
Channel 1
C2 (2)
Channel 2
C3 (3)
Channel 3
C4 (4)
Channel 4
C5 (5)
Channel 5
C6 (6)
Channel 6
C7 (7)
Channel 7
C8 (8)
Channel 8
5.9.2. Analogue Modules
The alarm types are fixed as shown below together with the default channel assignment.
Alarm Type AI2 Channel AI3 Channel
A AbsHi 1 1
B AbsHi 2 2
C AbsLo 1 1
D AbsLo 2 2
E AbsHi 1 3
F AbsHi 2
4
G AbsLo 1 3
H AbsLo 2
4
Table 5-3: Default Analogue I/O Alarms
5.9.3. Digital Modules
The alarm types are not fixed and in configuration mode may be set to any digital alarm type. The default
channel assignments are shown below.
Alarm Type DI4 Channel DI8 Channel
A Any 1 1
B Any 2 2
C Any 3 3
D Any 4 4
E Any 1 5
F Any 2 6
G Any 3 7
H Any 4
8
Table 5-4: Default Digital I/O Alarms
Page 87
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 85
5.10. INSTRUMENT STATUS ALARMS
These are self diagnostic alarms provided to simplify fault finding. Bit masks are provided to allow only selected
events to be reported in the appropriate alarm output.
Alarms are reported at the channel level, at the module level and at a system (IOC) level.
5.10.1. Individual Channel Status
The Status ChStat is reported for every channel on every module and is found in IO → Module0x → M0x_C1 to
C8.
Bit Value (Decimal) Bit set when
Bit 0 1 Sensor break detected
Bit 1 2 CJC failed
Bit 2 4 Channel not in use
Bit 3 8 Analogue output saturated
Bit 4 16 Initialising
Bit 5 32 Invalid Analogue Calibration data
Bit 6 64 Reserved / Analogue input saturated
Bit 7 128 Module fault (Module Status not zero)
Table 5-5: Channel Status Bits
An alarm is provided for this status word. The Status Alarm Output flag is set if any bit in the channel Status is
set AND the corresponding bit in the Status Alarm Bit Mask is set.
To use the Alarm the Status Alarm Bit Mask must be set in Configuration Mode. If the bit mask is set to 255 (Bits
0 to 7 set) then any Channel Status bit will set the alarm output. If the mask is set to 1 (bit 0 set) then only Sensor
Break detection will set the alarm output.
As with all alarms it may be configured to be latching or blocking. There is an alarm inhibit and an acknowledge.
5.10.2. Status of All Channels in a Module
At the Module level all its channels are reported in the Channel Alarms Status Word. This has the same format
as standard alarm status words.
Bit Value (Decimal) Set when:
0 1 Channel 1 Alarm active
1 2 Channel 1 Alarm acknowledged
2 4 Channel 2 Alarm active
3 8 Channel 2 Alarm acknowledged
4 16 Channel 3 Alarm active
5 32 Channel 3 Alarm acknowledged
6 64 Channel 4 Alarm active
7 128 Channel 4 Alarm acknowledged
8 256 Channel 5 Alarm active
9 512 Channel 5 Alarm acknowledged
10 1024 Channel 6 Alarm active
11 2048 Channel 6 Alarm acknowledged
12 4096 Channel 7 Alarm active
13 8192 Channel 7 Alarm acknowledged
14 16384 Channel 8 Alarm active
15 32768 Channel 8 Alarm acknowledged
Table 5-6: Channel Alarm Status Word
Page 88
2500 Controller Engineering Handbook
86 Part No HA027115 Issue 4.0 Mar -11
5.10.3. Status of All Channels in a System (IOC)
Operator → SYSTEM → IOStat is a Global IO Status word that consolidates all the IO status alarms into a single
word. Bits 0 to 7 are the OR of all the Channel Status bits Table 5-5, bits 8 to 11 the OR of all the Module Status
bits Table 5-8.
Bit Value (Decimal) Set when:
0 1 Any channel Sensor break detected
1 2 Any channel CJC failed
2 4 Any channel Channel not in use
3 8 Any channel Analogue output saturated
4 16 Any channel Initialising
5 32 Any channel Invalid Analogue Cal data
6 64 Reserved / Analogue input saturated
7 128 Any channel Module fault
8 256 Any Module is missing
9 512 Any Wrong Module fitted
10 1024 Any Unrecognised Module fitted
11 2048 Any Module Comms Error
12 4096 Reserved for future use
13 8192 Reserved for future use
14 16384 Reserved for future use
15 32768 Reserved for future use
Table 5-7: Global IO Status Word
5.10.4. Module Status
Module01 → MOD01 → ModSta is the Module Status for the module fitted in slot one.
Bit Value Bit set when
0 0 Module is OK
1 1 Module is missing
2 2 Wrong Module fitted
3 4 Unrecognised Module fitted
4 8 Module Comms Error
Table 5-8: Module Status
Note that the Summary Word is not an ‘alarm’ word, it reflects the state of the I/O.
Bit 0 is set if the value of channel 1 is >0.5 for analogue or digital modules.
Bits 1 to 7 are for channels 2 to 8. See Chapter 7.
5.10.5. System (IOC) Status
Operator → SYSTEM → InstSt is the Instrument Status word and provides information about problems with the
2500 IOC.
Bit Value Set when:
0 1 In Config Mode
1 2 Running Slowly
3 4 NV ram fail
4 8 Bad Custom Lin
5 16 Bad base size
9 32 I/O network watchdog
10 64 IO controller cold started
Table 5-9: Instrument Status Word
An alarm is provided for this status word. The Instrument Alarm Output flag is set if any bit in the Instrument
Status is set AND the corresponding bit in the Instrument Alarm Bit Mask is set.
To use the Alarm the Instrument Alarm Bit Mask must be set in Configuration Mode. If the bit mask is set to
2047 (Bits 0 to 10 set) then any Instrument Status bit will set the alarm output. If the mask is set to 1 (bit 0 set)
then only ‘in Configuration Level’ will set the alarm output.
As with all alarms it may be configured to be latching or blocking. There is an alarm inhibit and an alarm
acknowledge.
Note that Bit 2 (value 4)
will usually be set as
there is likely to be an
unused channel.
When IOStat has a value
4 (or zero) the red LED on
the 2500 IOC will be off.
Page 89
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 87
6. Chapter 6 Operator
This folder contains a number of system wide and diagnostic parameters.
6.1. LINEARISATION TABLES
These parameters are found in Operator → Lin Tables and are provided to allow the customised linearisation to
be checked. The list is only shown when ‘Options’ → ‘Parameter Availability Settings’ → ‘Hide Parameters and
L
ists when Not Relevant’ is not checked. They are used for cloning purposes only and under no circumstances
should any attempt be made to change or enter the value of a parameter in this list.
Figure 6-1: Lin Tables
6.2. DIGITAL COMMUNICATIONS
These parameters set up digital communications
Figure 6-2: Modbus Communications Parameters (Configuration Level)
Page 90
2500 Controller Engineering Handbook
88 Part No HA027115 Issue 4.0 Mar -11
6.2.1. Digital Communications Parameters
These parameters are found in Operator → COMMS. See also Chapters 9,10, 11 and 12 for further details.
Name Description Range Status
Addr
Comms Address. Unit address
Modbus:- normally taken from the IOC terminal unit digit switch (see section 2.6.3).
The digit switch allows addresses of 1 to 63 to be set. If the address switch is set to
zero, the ‘Addr’ parameter can be set in software. This software address is only used if
unit addresses higher than 63 are required.
Profibus:- range 0-127. Address can be set on the IOC terminal unit digit switch or in
software using this parameter.
Devicenet:- range 0-63. Address can be set on the IOC terminal unit digit switch or in
software using this parameter.
Ethernet-Modbus TCP slave id: range 0-63. Value can be set on the IOC terminal unit
digit switch or in software using this parameter.
Baud
Comms Baud Rate. Baud rate
Modbus:- range 9600 to 19200 see also note 1.
Profibus:- the parameter is read only
Devicenet:- Rates of 125, 250 or 500 can be set
Ethernet:- the parameter is not used, so is normally hidden
Parity
Comms Parity. Parity is available for Modbus, Profibus and Devicenet and must be set
to suit the master.
None (0) None. No parity
EvEn (1) Even. Even parity
Odd (2) Odd. Odd parity
Res
Comms Resolution. Modbus only:- normally set to ‘Full’, giving all the digits available
including those after the decimal point. The communications master must know how
to interpret the number as set in LOOP0x → L0xCFG → dEcP.
FuLL (0)
Full
Int (1)
Integer. Setting ‘Res’ to ‘Int’ will only return the integer value.
dELy
Comms Delay. Modbus only: normally set to ‘no’. It is only required if there is a
problem, particuarly with comms adaptors. The delay option leaves 10ms of quiet
time after each transaction.
no (0)
No delay
YES (1)
Delay selected in ms (1 –100)
FLAGs
Comms Special Case Flags. This parameter is for special use only and may be
changed in all modes, not only in configuration.
The following parameters may be hidden if not required for the operation of the instrument. To reveal uncheck the ‘Hide
Parameters’ box in ‘Options → Parameter Availability Settings’
Prot
Profibus Protocol. Select the Profibus protocol required.
DP (0) DP
DPv1 (1) DPv1
BaudLo
Comms Baud Rate Low Limit
BaudHi
Comms Baud Rate High Limit
AddLo
Address Low Limit
AddHi
Address High Limit
Page 91
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 89
The following parameters are only relevant to the Ethernet IOC:
IPaddr1
IP Address 1: in the standard Ethernet format, aaa.bbb.ccc.ddd, this is the
aaa field
IPaddr2
IP Address 2: in the standard Ethernet format, aaa.bbb.ccc.ddd, this is the
bbb field
IPaddr3
IP Address 3: in the standard Ethernet format, aaa.bbb.ccc.ddd, this is the
ccc field
IPaddr4
IP Address 4: in the standard Ethernet format, aaa.bbb.ccc.ddd, this is the
ddd field
Subnet1
Subnet Mask 1: in the standard Ethernet format, aaa.bbb.ccc.ddd, this is
the aaa field
Subnet2
Subnet Mask 2: in the standard Ethernet format, aaa.bbb.ccc.ddd, this is
the bbb field
Subnet3
Subnet Mask 3: in the standard Ethernet format, aaa.bbb.ccc.ddd, this is
the ccc field
Subnet4
Subnet Mask 4: in the standard Ethernet format, aaa.bbb.ccc.ddd, this is
the ddd field
Gateway1
Default Gateway 1: in the standard Ethernet format, aaa.bbb.ccc.ddd, this
is the aaa field
Gateway2
Default Gateway 2: in the standard Ethernet format, aaa.bbb.ccc.ddd, this
is the bbb field
Gateway3
Default Gateway 3: in the standard Ethernet format, aaa.bbb.ccc.ddd, this
is the ccc field
Gateway4
Default Gateway 4: in the standard Ethernet format, aaa.bbb.ccc.ddd, this
is the ddd field
PrefMst1
Preferred Master 1: in the standard Ethernet format, aaa.bbb.ccc.ddd, this
is the aaa field
PrefMst2
Preferred Master 2: in the standard Ethernet format, aaa.bbb.ccc.ddd, this
is the bbb field
PrefMst3
Preferred Master 3: in the standard Ethernet format, aaa.bbb.ccc.ddd, this
is the ccc field
PrefMst4
Preferred Master 4: in the standard Ethernet format, aaa.bbb.ccc.ddd, this
is the ddd field
MACaddr1
MAC Address 1: in the standard Ethernet format, aa-bb-cc-dd-ee-ff, this is
the aa-bb fields.
MACaddr2
MAC Address 2: in the standard Ethernet format, aa-bb-cc-dd-ee-ff, this is
the cc-dd fields.
MACaddr3
MAC Address 3: in the standard Ethernet format, aa-bb-cc-dd-ee-ff, this is
the ee-ff fields.
DHCPen
DHCP Enable:
Fixed (0) Fixed. Fixed IP addressing – DHCP disabled.
DHCP (1) DHCP. Dynamic IP addressing – DHCP enabled.
NetStat
Network Status: for diagnostics purposes
IPChanged
IP Changed: for diagnostics purposes
LocalAddres
Local Modbus Address: for diagnostics purposes
Page 92
2500 Controller Engineering Handbook
90 Part No HA027115 Issue 4.0 Mar -11
Note 1:- The table shows the baud rates supported in different versions:-
Modbus
Baud Rate Software Version V1 V2 V3
2400 (3)
4800 (2)
9600 (0)
19,200 (1)
38,400 (5)
Profibus
Baud Rate Software Version V1 V2 V3 V4
Set by the
master up
to 12MB
Note:- Version 4 is Profibus only
Devicenet
Baud Rate Software Version V1 V2 V3
125K (6)
250K (7)
500K (8)
Ethernet
Baud Rate Software Version V1 V2 V3
10BaseT
Page 93
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 91
6.3. SYSTEM
These parameters provide information about the system.
6.3.1. System Parameters
These parameters are found in Operator → SYSTEM.
Name Description Range Status
ReqIM
Requested Instrument Mode. The requested mode of the 2500 IOC
Operat (0)
Operating: Normal use
Stndby(1)
Standby: Input values still work but there are no calculations
Config (2)
Configuration: the controller is being set up and is not functioning
IM
Instrument Operating Mode. The actual mode of the 2500 IOC
Operat (0)
Operating: Normal use
Stndby(1)
Standby: Input values still work but there are no calculations
Config (2)
Configuration: the controller is being set up and is not functioning
II
Instrument Identity. A unique hex number for the 2500 product, displayed as
decimal as follows:-
Code 2500E 2500C
Modbus 2580
[9600]
2500
[9472]
Profibus DP 2581
[9601]
2510
[9488]
Profibus DPV1 2582
[9602]
2511
[9489]
Devicenet 2583
[9603]
N/A
Ethernet 2584
[9604]
N/A
AckAll
Global Alarm Acknowledge. Set to acknowledge all alarms. It resets itself.
no (0)
No acknowledge
YES (1)
Choose ‘Yes’ to acknowledge
AckIP
Global Alarm Ack Input. Used to acknowledge all alarms.
no (0)
No acknowledge (only if not wired)
YES (1)
Choose ‘Yes’ to acknowledge (only if not wired)
AckSrc
Global Alarm Ack Input Source. Modbus address of flag used to acknowledge all
alarms
-1 means it is not wired
Allows all alarms to be acknowledged by wiring to the address of a source
(configuration level only)
IOstat
Global IO Status. Summarises all channels of all modules, see section 5.10.3.
BaseSz
Base Size. Size of the base as identified by the IOC.
IOFail
I/O Fail Strategy. Defines IO behaviour in fault condition
Contin (0)
Continue – carry on as before
EntSby (1)
Enter Standby - go into Standby Mode on failure and stay there
Stndby (2)
Standby - Remain in Standby only whilst fault persists
IONwdg
I/O Network Watchdog Timeout. Set time before IO network watchdog is activated
after failure is detected.
On loss of Field communications for greater than a pre set time an action can be
taken, either to go into standby or set the network watchdog flag. The latter mode is
intended for use where a failure strategy is defined by the configuration of the IOC.
This strategy is set by the next parameter ‘NwdAct’.
A value of 0 disables the watchdog. Setting to a positive value switches the function
on.
h:m:s:ms
Page 94
2500 Controller Engineering Handbook
92 Part No HA027115 Issue 4.0 Mar -11
Name Description Range Status
IONrec
IO Network Recovery Time
NwdAct
I/O Network Watchdog Timeout. Defines the instrument behaviour when the
network watchdog is activated.
EntSby (0) Enter Standby. Go into Standby Mode on failure and stay there
Flag (1)
Set the network watchdog flag only
Nwdged
I/O Network Watchdog Flag. Indicates IO network has failed
StStby
Startup in Standby. (Config only) Defines IOC behaviour on powering up
no (0)
No - Operate normally
YES (1)
Yes - Remain in Standby Mode
STime
Sample Time. Indicates the current sample time the IOC is achieving
MaxST Maximum Sample Time. The maximum sample time the IOC has used. If the IOC is
failing to achieve the requested sample time this indicates what it can achieve.
ReqST Requested Sample Time. This is normally 110ms (0) but may be increased to 990ms
(8) in steps of 110ms for bigger systems.
SlowST Running Slower than Requested Flag. Set if the IOC is failing to achieve the
requested sample time.
no (0) IOC is achieving the requested sample time
YES (1) IOC is running slower than the requested sample time
SOrCt Slowed Down Counter. The number of times the ‘SlowST’ flag has been set.
ColdSt Cold Start Flag. Set after a non volatile RAM error has forced a re-initialisation to
default parameter values.
NVFail Non-Volatile Memory Failure. The IOC non volatile RAM has failed and it will remain
in Standby Mode whilst this condition persists.
ClinFl Custom Linearisation Failure. The IOC has detected failure in a custom linearisation
curve and it will remain in Standby Mode whilst this condition persists
InstSt Instrument Status. A status word which combines a number of the above flags.
See section 5.10.5. This is used for the Instrument Alarm.
Units Instrument Temperature Units. (Config mode) sets the temperature units
o
C (0) Celsius
oF (1) Farenheit
o
k (2)
Kelvin
Mask Instrument Alarm Bit Mask. (Config mode) set to select which of the ‘InstSt’ bits are
enabled (not masked) from the Instrument Alarm Status Word ‘AlmSW’. See section
5.10.5.
Inhibt Instrument Alarm Inhibit. To inhibit ‘AlmSW’
InhSrc Instrument Alarm Inhibit Source. Modbus address of the parameter used to inhibit
the instrument alarm
-1 means it is not wired
Bloc Instrument Alarm Blocking. (Config mode). After power up the alarm condition must
be OK first, before the alarm is allowed to be active. See section 5.4.
no (0) No blocking
YES (1) Yes – set for blocking alarm operation
Ltch Instrument Alarm Latching. (Config Mode) Set to Auto the alarm will latch until the
condition has cleared and it has been acknowledged. See section 5.5.
no (0) No latching
Auto (1) Automatic. The alarm continues to be active until both the alarm condition is removed AND the alarm is
acknowledged
mAn (2) Set to Manual the alarm must clear first, then be acknowledged.
Ack Instrument Alarm Acknowledge. See section 5.5.
no (0) No acknowledge
Page 95
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 93
Name Description Range Status
YES (1) Yes – Set to acknowledge alarm
OP Instrument Alarm Output. Flag set if ‘AlmSW’ is not zero.
OFF (0) No alarm
on (1) Alarm flag set
AlmSW Instrument Alarm Status Word. Returns the bitwise AND of ‘InstSt’ and the bit mask
‘Mask’.
The following parameters are used by external masters to control the ramp blocks in the 2500:
GHd Global SRL Hold Flag. Holds all ramps
GHdSrc Global SRL Hold Flag Source. (Config mode) Modbus address of flag used to hold
ramps
-1 means it is not wired
GSSync Trigger All Ramps. Triggers all ramps to provide a synchronised start.
no (0) Do not trigger ramps
YES (1) Global trigger active
ActIM
Actual operating mode of the IOC. Only appears when ‘Options’ → ‘Parameter
Availability Settings’ not checked
Operat (0) Operator mode – normal use
Stndby (1) Standby mode - I/P values still work but there are no calculations
Config (2) Configuration mode - the controller is being set up and is not functioning
LveCnf Enable IO Config in Operator mode. Enables changes to parameters and wires in IO
areas on line
.
Care is needed when changing this value
no (0) Configuration parameters read only in Operator mode
YES (1) Configuration parameters read/write in Operator mode
IS Instrument Operating State. Displays the level of operation
Operat (0) Operator level
Stndby (1) Standby mode - I/P values still work but there are no calculations
Config (2) Configuration mode - the controller is being set up and is not functioning
LveCnf (3) Live Configuration mode. Similar to operating mode
PaChgd Parameter Changed Status Word. This is a bit mapped field indicating modules
which have had parameters changed while in ‘LveCnf’. The parameters are
detailed in the list below:-
ALM01 to 16 A to H ALSP_1 to 8 Alarm SP
ALM01 to 16 A to H Hy_1 to 8 Alarm hysteresis
M01 to 16_C1 to 8 SenS Invert
M01 to 16_C1 to 8 VALH Eng val high
M01 to 16_C1 to 8 VALL Eng val low
M01 to 16_C1 to 8 IOH Electrical high
M01 to 16_C1 to 8 IOL Electrical low
M01 to 16_C1 to 8 SBDet Sensor break bleed enable
M01 to 16_C1 to 8 FltAct Fault action
M01 to 16_C1 to 8 LinTyp Linearisation type
Bit 0 = module slot 1 ... bit 15 = module slot 16.
May be used over digital communications
It is possible to reset the bits to 0 but not set to 1
Page 96
2500 Controller Engineering Handbook
94 Part No HA027115 Issue 4.0 Mar -11
Name Description Range Status
ApName Application Name This is an 8 character field for the manual entry of a
configuration name.
E.g. the name of the clone file currently loaded.
ApVers Application Version. A 5 digit field for the manual entry of the application version.
E.g. the clone file version.
TStamp Application Time Stamp. A 6 digit field to manually store the application
date/time..
CustabN1 Custom Table 1 Name. Name of the custom linearisation table downloaded with
the linearisation data
CustabN2 Custom Table 2 Name. Name of the custom linearisation table downloaded with
the linearisation data
CustabN3 Custom Table 3 Name. Name of the custom linearisation table downloaded with
the linearisation data
Page 97
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 95
6.4. PASSWORD ENTRY
These parameters allow the user to enter different levels of operation
6.4.1. Password Entry Parameters
These parameters are found in Operator → PASSWD
Name Description Range Status
UserPW
User Calibration Password. The correct value has to be entered to enable User
Calibration. See Chapter 13.
0 -32767
RefPW
Reference Calibration Password. The correct value has to be entered to enable
Reference Calibration. See Chapter 13.
0 -32767
6.5. PASSWORD SET UP
These parameters are in configuration level only and allow the user to set up the passwords for different levels
of operation.
6.5.1. Password Set Up Parameters
These parameters are found in Operator → SETPW
Name Description Range Status
DefUPW
User Calibration Password Configuration.. (Config mode only). The value used
for the User Cal password
0 -32767
DefRPW
Reference Calibration Password. (Config mode only). The value used for the
Reference Cal password
0 -32767
6.6. DIAGNOSTICS
These parameters are used to assess the cycle time that the 2500 unit can achieve. It is particularly useful for
2500 units with the 8 PID loops.
6.6.1. Diagnostic Parameters
These parameters are found in Operator → DIAG
Name Description Range Status
Ctime
Control Task Duration in Ticks. This is in ‘ticks’ of 1.83ms (1/60 of 110ms) and is
the time taken to calculate all the PID loops.
MaxCT
Maximum Control Task Duration. This is the maximum number of ‘ticks’ used to
calculate the PID loops. This can be reset to 0.
MaxCT should not exceed the number indicated below:-
Base Size MaxCT ticks
4 <56
8 <52
16 4
If ‘MaxCT’ does approach or exceed this number the ‘Operator.SYSTEM → Requested Sample Time’ should be
increased.
Other diagnostic parameters displayed give the high and low A/D conversion counts for each channel. These
are for engineering purposes only.
Page 98
2500 Controller Engineering Handbook
96 Part No HA027115 Issue 4.0 Mar -11
6.7. SYSTEM DESCRIPTIONS
These parameters provide descriptions of system parameters. They are found in Operator → DESCR
Name Description Range Status
CC
Company ID
II
Product ID
VO
Instrument Version Number
SerialNo
Instrument Serial Number
PCode1
Feature Pass Code 1. Used to set which features are available: number of loops, user
calculations.
PCode2
Feature Pass Code 2. Used to set which features are available: number of loops, user
calculations.
FitA
Feature Identifier Table Address
PidCS
Product ID Table Checksum
nFID
Number of Feature Identifiers
F1
Feature1: Indirect Modbus Address
F1_1
Address of Read Only Indirection Table
F1_2
Address of Read/Write Indirection Table
F1_3
Not Used
F2
Feature2: Modbus Word Ordering
F2_1
High order word in low reg. addr
F2_2
Not Used
F2_3
Not Used
F3
Feature3: Modbus Function Codes
F3_1
FCs 3;4;6;7;8 and 16 supported
F3_2
FCs 17-19 NOT supported
F3_3
FCs 70 and 71 supported
F4
Feature4: Analog Value Formats
F4_1
16 bit scaled & IEEE & 32 bit int
F4_2
Not Used
F4_3
Not Used
F5
Feature5: Ethernet Parameters
F5_1
Supported Ethernet parameters
F5_2
Ethernet Base Address
F5_3
Not Used
nindRO
Read Only Modbus indirect table size
nindRW
Read/Write Modbus indirect table size
Page 99
2500 Controller Engineering Handbook
Part No HA027115 Issue 4.0 Mar -11 97
7. Chapter 7 I/O MODULES
7.1. OVERVIEW
In the 2500 system, I/O Modules perform equipment interface functions to measure or generate raw voltage,
resistance or current. Most transducer types can be connected straight into the I/O module via screw terminals.
Each I/O Module is dedicated to a particular function - analogue or digital, input or output. Channels on a
module may be set for different functions; for example, channel 2 of an AI2 might be set to work with a Zircionia
probe, and channel 1 set to a thermocouple range to measure the probe temperature.
Each channel can be considered as an instance of a design block (see section 3.7), capable of scaling, filtering,
A-to-D or D-to-A conversions, de-bounce, linearisation, and more - within the reasonable limits of the channel
type. Each channel has a set of parameters providing for each feature. These parameters can be displayed in
lists and manipulated using iTools.
The I/O Module itself is also considered a design block, with identity and status parameters.
7.2. I/O BLOCKS
Figure 7-1: For maximum design flexibility all modules are packaged as plug in modules
Some modules (particularly the analogue input types) are
supported with different Terminal Units, optimizing performance
for specific input ranges.
Figure 7-2: The plant wiring is accommodated by screw terminals in matching terminal units
Page 100
2500 Controller Engineering Handbook
98 Part No HA027115 Issue 4.0 Mar -11
7.3. I/O MODULE INDICATOR LEDS
All modules support status indicator LED's to reflect I/O terminal status.
All I/O modules offer a green indicator. This is illuminated when the module is fitted and powered and when
the IOC matches the 'ReqID' parameter for that base slot with the actual module type 'ActID'.
Figure 7-3: Module Status Indication
The green status LED should be steady; any flash or blink indicates a system or module hardware problem.
Figure 7-4: Analogue I/O Channel Status Indication
Figure 7-5: Digital I/O Channel Status Indication
Note that the indicators in DI4, DI6 and DI8 modules track the processed data reported to the IOC, not the
terminal condition. There could be a slight difference if the channel has a long de-bounce period specified, or
when using the pulse detect channel type.
All Analogue I/O modules also support a channel
status LED for each channel. These indicators are red
and show channel status - illuminated if there is a
channel problem.
LED ON OFF
Red Initialising, or I/O overload Normal
operation
Flashing Blinking
Bad cal data Calibrating
LED ON OFF
Yellow Digital input Logic 1, input
voltage high, or contact closed.
Digital output Logic 1, output
voltage high, or (RLY4) contact
closed.
Digital input Logic 0, input
voltage low, or contact open.
Digital output Logic 0, output
voltage low, or (RLY4) contact
open.
Note: Digital Output modules must have a 24V power supply connected to the
terminal unit in order to drive the LEDs.
The Digital I/O modules (including the RLY4) all support an LED associated
with each channel. These indicators are yellow and show channel status, lit
for logic 1 (on).
LED ON OFF
*
Green
Normal
operation
Fault Condition
No power, IOC comms or
unrecognised module type
Loading...