Watlow 8LS User Manual
8LS
User’s Guide
Watlow Controls
1241 Bundy Blvd.
Winona, MN 55987
Customer Service
Phone: (800) 414-4299
Fax: (800) 445-8992
Technical Support
Phone: (507) 494-5656
Fax: (507) 452-4507
Email: wintechsupport@watlow.com
Part No. 10585-00. Revision 9.2
July 1996
Copyright © 1996
Watlow Anafaze
Information in this manual is subject to change without notice. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted in any form without written permission
from Watlow Anafaze.
Warranty
Watlow Anafaze, Incorporated warrants that the products furnished under this Agreement will be
free from defects in material and workmanship for a period of three years from the date of shipment. The customer shall provide notice of any defect to Watlow Anafaze, Incorporated within one
week after the Customer's discovery of such defect. The sole obligation and liability of Watlow
Anafaze, Incorporated under this warranty shall be to repair or replace, at its option and without
cost to the Customer, the defective product or part.
Upon request by Watlow Anafaze, Incorporated, the product or part claimed to be defective shall
immediately be returned at the Customer's expense to Watlow Anafaze, Incorporated. Replaced or
repaired products or parts will be shipped to the Customer at the expense of Watlow Anafaze,
Incorporated.
There shall be no warranty or liability for any products or parts that have been subject to misuse,
accident, negligence, failure of electric power or modification by the Customer without the written
approval of Watlow Anafaze, Incorporated. Final determination of warranty eligibility shall be
made by Watlow Anafaze, Incorporated. If a warranty claim is considered invalid for any reason,
the Customer will be charged for services performed and expenses incurred by Watlow Anafaze,
Incorporated in handling and shipping the returned unit.
If replacement parts are supplied or repairs made during the original warranty period, the warranty
period for the replacement or repaired part shall terminate with the termination of the warranty
period of the original product or part.
The foregoing warranty constitutes the sole liability of Watlow Anafaze, Incorporated and the customer's sole remedy with respect to the products. It is in lieu of all other warranties, liabilities, and
remedies. Except as thus provided, Watlow Anafaze, Inc. disclaims all warranties, express or
implied, including any warranty of merchantability or fitness for a particular purpose.
Please Note: External safety devices must be used with this equipment.
Contents
Overview 1
Introduction 5
System Diagram.....................................................................2
Parts List ..........................................................................2
Safety .....................................................................................3
Specifications.........................................................................7
Analog Inputs...................................................................7
Control Capability............................................................8
Digital Outputs.................................................................8
Digital Inputs ...................................................................8
Pulse Counting Input .......................................................8
Serial Interface .................................................................8
Power Supply...................................................................8
Installation 9
Read This Before Installation ................................................10
Mounting The 8LS.................................................................11
External Wiring................................................................13
General Wiring Requirements .........................................13
Cable Recommendations .................................................15
Noise Suppression............................................................16
Terminal Block And Connector Layout ..........................18
RTB Connections.............................................................19
Analog Inputs...................................................................20
Input Scaling ..........................................................................21
Resistor Installation .........................................................22
Voltage Inputs..................................................................23
Milliamp Inputs................................................................23
Thermocouple Inputs .......................................................23
RTD Inputs ......................................................................24
Infrared Non-contact Temp. Sensors ...............................24
Pulse Input .......................................................................25
Carbon Probe Input..........................................................25
Control Outputs......................................................................27
PID Output Termination TB (Primary) or
Flat Ribbon (Secondary)..................................................27
8LS User’s Guide i
PID Control Relay Outputs..............................................28
Primary Screw Terminal Outputs ....................................28
Digital Outputs On The Screw Terminal Blocks.............29
Primary Analog Outputs ..................................................29
Analog Output Dip Switch Setting
for 0-5v/4-20mA ..............................................................30
CPU Dip Switch...............................................................31
Secondary Outputs 50 Pin Ribbon Cable ........................31
Communications Set-up and Connections.............................33
RS-232 Connections........................................................33
RS-485 Description And Connections.............................34
Using the 8LS 37
Front Panel.............................................................................37
Front Panel Keys..............................................................38
Displays .................................................................................40
Bar Graph Display ...........................................................40
Single Loop Display ........................................................41
Scanning Display .............................................................41
Alarm Display..................................................................41
Operator Menus .....................................................................43
Changing the Setpoint......................................................43
Selecting Status Mode .....................................................43
Autotune...........................................................................44
Ramp/Soak.......................................................................44
ii 8LS User’s Guide
Setup 45
How to enter the Setup menus? .......................................45
How to edit a menu? ........................................................45
Setup Global Parameters Menu .............................................47
Save as Job.......................................................................48
Restore a Job....................................................................48
Set Alarm Delay...............................................................48
Set R/S Time Base ...........................................................49
Lock Panel .......................................................................49
Power Up Output Status ..................................................49
Controller Address...........................................................50
Communication Error Checking......................................50
Communication Baud Rate..............................................51
Communication Protocol .................................................51
AC Line Frequency..........................................................51
EPROM Version ..............................................................52
Setup Inputs Menu .................................................................53
Input Type........................................................................54
Pulse Sample Time ..........................................................55
Input Units .......................................................................55
Linear Scaling Menus ......................................................56
Input Offset ......................................................................58
Setup Control Menu...............................................................59
Heat/Cool PB ...................................................................60
Heat/Cool TI ....................................................................60
Heat/Cool TD...................................................................60
Heat/Cool Output Filter ...................................................60
Heat/Cool Spread .............................................................61
Setup Outputs Menu ..............................................................62
Output Type .....................................................................63
Cycle Time.......................................................................63
Output Action ..................................................................64
Output Limit ....................................................................64
Output Limit Time ...........................................................65
Nonlinear Output Curve...................................................65
Heat Output......................................................................66
Setup Alarms..........................................................................67
Alarm Types ....................................................................68
High Process Alarm Setpoint...........................................69
High Process Alarm Status ..............................................69
High Process Alarm Output Number...............................69
Deviation Band Alarm .....................................................70
Deviation Band Alarm Status ..........................................70
High Deviation Alarm Output Number ...........................70
Low Deviation Alarm Output Number............................71
Low Process Alarm Setpoint ...........................................71
Low Process Alarm Status...............................................71
Low Process Alarm Output Number ...............................72
Alarm Deadband ..............................................................72
Alarm Delay.....................................................................72
Test I/O ..................................................................................73
Digital Input Testing........................................................73
Test Output ......................................................................74
Digital Output Test ..........................................................74
Tuning and Control 75
Introduction............................................................................75
Control Modes .......................................................................76
Control Outputs................................................................78
Digital Output Control Forms..........................................78
8LS User’s Guide iii
Setting Up and Tuning PID Loops ........................................80
General PID Constants by Application..................................82
Troubleshooting 85
Stand Alone Systems .............................................................85
Checking Control Outputs ...............................................85
Checking Digital I/O........................................................85
Computer Supervised Systems ..............................................86
Computer Problems .........................................................86
Computer Software ..........................................................86
Communications Problems ..............................................87
Serial Interface .................................................................87
Appendix A: Ramp Soak 89
Introduction............................................................................89
R/S Features.....................................................................89
Specifications...................................................................90
Configuring Ramp/Soak ........................................................90
Setting the R/S Time Base...............................................91
Editing R/S Parameters....................................................91
Choosing a Profile to Edit................................................91
Copying the Setup from Another Profile.........................92
Editing the Tolerance Alarm Time ..................................92
Editing the Ready Setpoint ..............................................93
Editing the Ready Event States........................................93
Choosing an External Reset Input ...................................94
Editing a Segment............................................................94
Setting Segment Time......................................................94
Setting a Segment Setpoint ..............................................95
Configuring Segment Events ...........................................95
Editing Event Outputs......................................................96
Changing Event States .....................................................96
Editing Segment Triggers ................................................96
Assigning an Input to a Trigger .......................................97
Changing a Trigger’s True State......................................97
Latching or Unlatching a Trigger ....................................97
Setting Segment Tolerance ..............................................98
Ending a Profile ...............................................................98
Repeating a Profile...........................................................98
Using Ramp/Soak ..................................................................99
Assigning a Profile to a Loop...........................................99
Running a Profile .............................................................100
Ramp/Soak Displays........................................................101
iv 8LS User’s Guide
Holding a Profile or Continuing from Hold.....................103
Resetting a Profile............................................................104
Appendix B: 8LS-CP 105
Key Features ....................................................................105
System Configuration ............................................................106
Specifications.........................................................................108
Analog Inputs...................................................................108
Control Capability............................................................108
CP Control .............................................................................109
Trim Gas Temperature Alarm Output ...................................109
Recommended CP Trim Gas Alarm for Continuous
Applications .....................................................................109
Recommended CP Trim Gas Alarm for Batch Applications110
Carbon Probe .........................................................................111
General Guidelines ..........................................................111
Probe Burn Off.......................................................................112
Carbon Probe Burn Off Requirements: ...........................112
Burn Off Procedures ........................................................112
Burn Off Function............................................................113
Setup Menus ..........................................................................114
Setup Inputs .....................................................................114
Setup Carbon Burn Off ....................................................116
Setup Alarms....................................................................119
CP and DP Display ..........................................................119
Appendix C: 8LS Cascade 121
Introduction............................................................................121
8LS Cascade Menus...............................................................121
Cascade Main Menu ........................................................121
Choosing the Primary Loop.............................................122
Setting the High End of the Secondary Setpoint .............122
Setting the Low End of the Secondary Setpoint ..............122
Glossary 123
8LS User’s Guide v
vi 8LS User’s Guide
Overview
Overview
This manual describes how to install, setup, and operate an 8LS
controller. Included are six chapters, Appendixes describing the 8LS-CP
(Carbon Potential) and the 8LS-RS (Ramp/Soak), and a glossary of
terms. Each chapter covers a different aspect of your control system and
may apply to different users. The following describes the chapters and
their purpose.
•
Introduction: Gives a general description of the 8LS and its related
specifications.
•
Installation: Describes how to install the 8LS.
•
Using the 8LS: Provides an overview of system displays and opera-
tor menus.
•
Setup: Describes all the setup displays for the controller, and how to
access them.
•
Tuning and Control: Explains PID control and provides tips for
tuning your system.
•
Troubleshooting: Gives some basic guidelines for solving control
problems.
•
Appendix A: Describes the Ramp and Soak function in the 8LS con-
troller.
•
Appendix B: Describes the 8LS-CP controller
tures, and additional menus.
—
its function, fea-
8LS User’s Guide 1
Overview
System Diagram
The illustration below shows how the parts of the 8LS are connected.
When unpacking your system, use the diagram and parts list below to
ensure all parts have been shipped. Please don’t hesitate to call Watlow
Anafaze’s Technical Service Department if you have problems with
your shipment, or if the 8LS components are missing or damaged.
Signal Inputs and
Primary Outputs
50-Pin Ribbon Cable
8LS to RTB
8LS
Parts List
50-Pin RTB
Secondary Outputs
and Alarms
•
8LS controller
•
Controller mount kit
•
RTB
•
50 pin flat ribbon cable
•
8LS manual
System Power
2 8LS User’s Guide
Safety
Overview
Watlow Anafaze has made efforts to ensure the reliability and safety of
the 8LS
applications. Please note that, in any application, failures can occur.
These failures may result in full control outputs or other outputs which
may cause damage to or unsafe conditions in the equipment or process
connected to the 8LS controller.
Good engineering practices, electrical codes, and insurance regulations
require that you use independent external safety devices to prevent
potentially dangerous or unsafe conditions. Assume that the Watlow
Anafaze 8LS controller can fail with outputs full on, outputs full off, or
that other unexpected conditions can occur.
Install high or low temperature protection in systems where an
overtemperature or undertemperature fault condition could present a fire
hazard or other hazard. Failure to install temperature control protection
where a potential hazard exists could result in damage to equipment and
property, and injury to personnel.
controller and to recommend safe usage practices in systems
The 8LS includes a reset circuit that sets the control outputs off or to the
—
data stored in memory if the microprocessor resets
of a power failure and power return. If a memory-based restart will be
unsafe for your process, program the 8LS controller to restart with
outputs off. For additional safety, program the computer or other host
device to automatically reload the desired operating constants or process
values on return of operating power. However, these safety features do
not eliminate the need for external, independent safety devices in
potentially dangerous or unsafe conditions.
Watlow Anafaze also offers ANASOFT
program for IBM-AT
event of a reset, ANASOFT will reload the 8LS controller with the
current values in computer memory. The user must ensure that this reset
will be safe for the process. Again, use of ANASOFT does not eliminate
the need for appropriate external, independent, safety devices.
Contact Watlow Anafaze immediately if you have any questions about
system safety or system operation.
®
or IBM-PC® compatible computers. In the
®
normally the result
, an optional software
8LS User’s Guide 3
Overview
4 8LS User’s Guide
Introduction
The 8LS is a powerful 1/4 DIN controller that delivers 8 fully
independent loops of PID control. It can function as a stand alone
controller and as the key element in a computer supervised data
acquisition and control system. An LED front panel display and a touch
keypad are available for local entry of control and other operating
parameters. The 8LS can also be supervised by a computer or
programmable controller through the standard serial interface.
The 8LS features include:
Direct Connection of Mixed Sensors: Versatile analog inputs let you
directly connect most industrial T/C sensors. Thermocouple inputs
feature reference junction compensation, linearization, upscale break
detection, and a choice of
scaling resistors on the 8LS inputs.
Introduction
°
F or °C display. Other analog inputs require
Automatic Scaling: All sensors can be automatically scaled by
entering any two measurement points. For example, to scale a pressure
sensor, enter two points such as 28% is 80 PSI, and 82% is 260 PSI. All
subsequent values will be in PSI.
Selectable Control Outputs: Each PID primary control output can be
selected as digital for on/off, time proportioning, or as analog for
proportional 0-5vdc /4-20madc. The PID secondary output can be
selected as digital for on/off, time proportioning, or distributed zero
crossing. Each loop can be independently set for on/off, P, PI, or PID
control with reverse acting [heat] or direct acting [cool] output.
Complete Process Monitoring: A unique alarm capability is included.
You can set a deviation band alarm, and high and low process [fixed]
alarms independently for each loop. In addition to global annunciator
digital output, each alarm can include a single or grouped digital output.
For example, the digital output from all the high process alarms can be
directed to a single output for automatic process shutdown.
Front Panel or Computer Operation: You can set up and run the 8LS
from the front panel or from a local or remote computer. We offer
ANASOFT, an IBM PC or compatible menu driven program, to set the
8LS parameters. In addition, ANASOFT features graphic trend plotting,
process overviews, printouts, and data archiving.
Multiple Job Storage: You can store up to 8 jobs in protected memory
and access them by entering a single job number. Each job is a set of
operating conditions, including setpoints and alarms. Thus if a single
oven is producing multiple products, entry of the job number will setup
all the loops.
8LS User’s Guide 5
Introduction
Dual Output Standard: The 8LS includes dual control outputs for
each loop with a second set of control constants for heating and cooling
applications.
Optional Ramp and Soak: The 8LS is available with a built in
powerful Ramp and Soak programmer for batch processing.
Optional Extruder or Carbon Potential: The 8LS is available with
built in Extruder or Carbon Potential parameters for controlling these
processes.
6 8LS User’s Guide
Specifications
Analog Inputs
Analog inputs 8, solid state, differential
Optical isolation 120 Vac between inputs; 175 Vac from input to ground
A/D converter Integrating voltage to frequency
DC voltage range -10 to 60 mV. You can change it with scaling resistors to
Resolution 0.02%, greater than 12 bits
Calibration Automatic zero and full scale
Temperature coefficient Less than 50 ppm/C, 0.005%/°C
Normal mode rejection 60 db at 60 Hz, full scale range maximum
Loop update time 2 times per second, every input
T/C burnout Full upscale reading of input standard
DC milliamp inputs 4-20 mA, 10-50 mA, 0-50 mA, etc., with scaling resistors
Input Range 0-1V, 0-5V, 0-10V, 0-12V, up to 0-25 Vdc, with scaling
Infrared inputs Power supply included, with scaling resistors
Source impedance Measurements are within specification with up to 500
Introduction
any range from 0 to 25V
Accuracy 0.05% at 25°C
resistors
ohms source resistance
Thermocouple Ranges
J -350 to 1400°F -212 to 760°C
K -450 to 2500°F -268 to 1371°C
T -450 to 750°F -268 to 399°C
B 150 to 3200°F 66 to 1760°C
S 0 to 3200°F -18 to 1760°C
R 0 to 3210°F -18 to 1766°C
N -450 to 2370°F -268 to 1299°C
RTD Ranges
RTD1 -148.0 to +572.0°F -100 to 300°C0.1°
RTD2 -184.0 to +1544.0°F -120 to 840°C0.2°
8LS User’s Guide 7
Introduction
Control Capability
Number of loops 8, dual output
Control outputs Cycle Time Proportioning, Distributed Zero Crossing, On/Off or Ana-
Digital PID outputs Nominal 5 Vdc at 20 mA to drive optically-isolated solid-state relays
Analog PID outputs Selectable 0 to 5 Vdc at 20 mA maximum or 4 to 20 mAdc 500 ohm
Output resolution 12 bits
Digital Outputs
log; all independently selectable for each loop
Control action Reverse [heat] or Direct [cool], independently selectable for each
loop
Cycle time Programmable for each loop, 1-255 seconds
maximum load
Number 31
Configuration 1 Global Alarm (terminals)
30 for alarms or events (1-4 terminals, 5-30 RTB connector)
Digital Inputs
Pulse Counting Input
Serial Interface
Type RS-232 or RS-485 4 wire, jumper select
Isolation RS-232: optical
Baud Rate 2400 or 9600, menu selectable
Protocol Form of ANSI X3.28-1976, compatible with Allen Bradley
Error check BCC or CRC, menu selectable
No. of controllers Each communications line: 32 with RS-485, 1 with RS-232
Number 12
Configuration 12 for Ramp/Soak triggers
(1-8 RTB connector, 9-12 terminals)
Number Selectable 1 per unit
Type Open collector, 5 Vdc max.
Frequency 1 to 20 Khz
RS-485: To RS-485 Specification
PLC, full Duplex
Power Supply
8 8LS User’s Guide
Power input 85 to 132 Vac, .1A typical, 47 to 440 Hz
Installation
Installation
This section explains how to install the 8LS. The instructions are written
for nontechnical users. If you are technically proficient and they seem
simple, at least skim all of the instructions, so you don’t miss anything
vital.
These symbols are used throughout this manual:
DANGER
This symbol warns you of a hazard to human life.
WARNING
This symbol warns you of possible damage to
property or equipment.
NOTE
This symbol denotes information you must know
in order to proceed.
8LS User’s Guide 9
Installation
Read This Before Installation
DANGER
Shut off power to your process before you install
the 8LS. High voltage may be present even when
power is turned off! Reduce the danger of electric
shock after installation--mount the 8LS in an
enclosure that prevents personal contact with electrical components.
The 8LS measures input signals that are not normally referenced to ground, so the 8LS inputs and
other signal lines can have high voltage present
even when power is turned off. For example, if you
inadvertently short a thermocouple to the AC
power line.
WARNING
During installation and wiring, place temporary
covers over the housing slots and the rear of the
8LS so dirt and pieces of wire don't fall through
the slots. When you are finished with installation,
remove the covers.
Install the 8LS so the airflow to the slots in the
housing is not restricted after installation. Make
sure that other equipment does not block airflow
to the housing slots.
Use #20 or #22 AWG wires and trim wire insulation to 1/4" (5 mm). Wire should fit inside the
terminal with no bare wire exposed, to prevent
contact between wires and the grounded case. Tin
any stranded wire.
Support power, input and output cables to reduce
strain on the terminals and to prevent wire
removal.
NOTE
Choose a panel location that leaves enough clearance to install and remove the 8LS and its
components.
10 8LS User’s Guide
Mounting The 8LS
Installation
The 8LS consists of a 1/4 DIN housing with a front plug in electronics
module. The 8LS-OF (Open Frame) is suitable for sub-plate mounting
inside an enclosure without a front panel. An 8LS-DK will supply the
front panel keyboard with a 10-foot plug- in cable.
For optimum performance when directly connecting thermocouple
inputs, the unit should be protected from thermal shocks whenever
possible. This will minimize any temperature gradients across the
terminal strips and ensure the highest accuracy.
1. Use the dimensions below to cut a hole in the panel.
92 mm
3.6’’
92 mm
3.6 ’’
Cut the hole carefully; the 1/4 DIN specification only allows a front
panel of 96mm x 96mm [3.78in x 3.78in], so there’s not a lot of room
for error.
2. After the hole is cut, insert the 8LS through the front of the panel and
screw the top and bottom clamps into place. If excessive vibration is
anticipated a rear support may be required both for the 8LS and the
interconnecting cables.
8LS User’s Guide 11
Installation
.
Front
LOOP PROCESS UNITS
1234 56 7 8
ALARM SETPOINT STATUS OUTPUT%
YES
ALARM
ACK
NO
CHNG
SP
3.78’’
96 mm
BACK
MAN
AUTO
ENTER
RAMP
SOAK
3.78’’
96 mm
3.58 ’
90.9 mm
Side
Rear
PIO
TB4
’
TB3
TB1
90.9 mm
TB2
3.58 ’’
3.78’’
96 mm
10.5’’
266.7mm
9.4’’
238.7mm
3.58’’
90.9
mm
12 8LS User’s Guide
3.78’’
g
g
(
Installation
Remote Panel Mounting Dimensions
Notes:
1. Dashed line indicates panel outline.
2. Drill holes as indicated.
3. Install
rommet and feed wire
through grommet.
4. Attach panel usin
from behind).
4 #4 screws
External Wiring
During wiring, it is recommended that the 8LS electronics be removed
or that temporary covers be put over the housing slots to ensure pieces
of wire do not enter the housing and lodge in the electronics. Always
ensure that the housing is clean when the electronics is plugged in.
A successful installation of an 8LS control system depends on selecting
the proper equipment and using correct installation techniques with
appropriate material. One area of concern is the wiring type and
placement of the wiring.
0.29’’
3.20’’
To p
125 dia
4 places
7/16 dia
Insert grommet
3.20’’
0.29’’0.91’’
3.78’’
The wiring is selected according to the function of the wire, the
installation requirements, and the possible mechanical electrical
problems that may occur.
The function of the wire is divided into two basic categories:
Outputs
. The process control requirements will dictate the
Inputs
type
and
of
inputs and the outputs along with the mechanical electrical requirements
of the individual installation.
The term AC power is applied to the 120 VAC control supply. High
power is applied to 240 VAC or higher, primarily used for control loads.
General Wiring Requirements
1. Use stranded wire. Solid wire is recommended for fixed service
and tends to make intermittent connections when moving the field
wiring around for maintenance.
8LS User’s Guide 13
Installation
2. Use 20 or 22 AWG size wire. The use of 16,18,20,22, or 24 AWG is
permissible also. The power requirement is not a factor in the wire
size. Only the mechanical strength and the ohmage of the wire may
be factors to consider. Smaller or larger sizes are not easily
installed, may be easily broken and/or cause intermittent connections.
3. Use shielded wire. The electrical shield is used primarily to protect
from unwanted electrical noise.
Normal use of the input wiring shield is to connect one end only to
the 120 VAC panel ground at the 8LS panel location. Another method
is to connect it at the sensor site ground and to the Analog Ground
terminal of the 8LS.
Normal use of the output wiring shield would be to connect one end
only to the 120 VAC panel ground in the panel that the 8LS is
mounted in. Actual use of the shields will be determined by the
installation requirement.
For additional noise suppression measures see NOISE SUPPRESSION FOR Digital Outputs.
4. Use Thermocouple Extension Wire for all thermocouple (T/C)
inputs. Most T/C Ext. Wire is solid wire unshielded. When using
such, the shield function cannot be utilized and only 16, 18, or 20
AWG should be used. Install all T/C wiring in its own conduit away
from AC Power and High Power wiring. Depending on type and wire
size up to 400-500 feet in length may be used to be within stated
accuracy and source impedance.
5. Use multiconductor stranded shielded cable for analog inputs. Most
inputs will use a shielded twisted pair, but some may require a 3 wire
input. Run all analog input wiring in its own conduit away from AC
Power and High Power wiring. Wire sizes of 20, 22, or 24 AWG may
be used.
6. Use multiconductor stranded shielded cable for analog outputs and
PID digital outputs connected to panel mount SSR's. The analog
output will normally use a twisted pair while the digital outputs will
be up to 9 or 20 conductors depending on wiring techniques. All
cables will be shielded. The wiring size will normally be 24 AWG.
The maximum length for the digital outputs should not exceed 25
feet. The maximum length for the analog outputs should not exceed
400 feet. All wiring must be in a separate conduit away from AC
Power and High Power wiring.
When using the 50 conductor flat ribbon cable for the I/O, use of
the 50-pin connector is recommended for both ends of the cable.
The wire is too small to withstand much flexing when connected to
a screw terminal. The cable length should not exceed 15 feet.
7. When installing communications wiring, by pulling in an extra pair, a
sound power phone system could be used for communications
between the 8LS and the computer. This could be used for maintenance, checking calibration and many other functions. A David Clark
#H5030 sound powered system has been used successfully in systems requiring this function.
8. When installing any I/O wiring to the 8LS inside a panel, it should
never be run in the same bundle as AC power wiring.
14 8LS User’s Guide
Cable Recommendations
Installation
Wiring bundles of low power Watlow Anafaze circuits next to bundles of high power AC wiring should never be done. The physical
separation of the high power circuits from the controllers should be
of prime importance. In fact, most AC voltage high power circuits are
installed in a separate panel.
Use these cables or their equivalent.
Function MFR P/N
Analog Inputs Belden #9154
Belden #8451
RTD Inputs Belden #8772
Belden #9770
T/C Inputs T/C Ext. Wire 2
Carbon Probe Input Belden #88760 2 18
Digital PID Outputs and Digital
I/O
Analog Outputs Belden #9154
Computer Communication:
RS232, RS422, RS485, or 20
mA
Belden #9539
Belden #9542
Ribbon Cable
Belden #8451
Belden #9729
Belden #9730
Belden #9842
Belden #9843
# of
Wires
2
2
3
3
9
20
50
2
2
4
6
4
6
AWG
20
22
20
22
24
24
20
22
24
24
24
24
8LS User’s Guide 15
Installation
Noise Suppression
When using the digital outputs from Watlow Anafaze multiloop
controllers to energize dry contact electrical-mechanical relays with
inductive loads, generation of RFI may become a problem.
This may cause the 8LS display to blank out and then re-energize as if
power had been momentarily turned off. It may also cause the CPU in
the equipment to reset, losing the PID output levels. It may also damage
the digital output IC circuit, thus not being able to energize the digital
outputs. If the IC circuit is damaged, factory repair will be required.
The type of loads that may cause a problem are motor starters, alarm
horns, etc. The RFI is generated upon opening of the metallic relay
contacts.
To correct the problem of RFI noise problems:
1. Use Solid State Relays (SSR) wherever possible in place of electricalmechanical relays (E-M relays).
2. When using E-M relays, if possible do not mount them in the same
panel as the Watlow Anafaze equipment.
3. Separate the 120 vac power leads from the low level input and outputs leads from the Watlow Anafaze. Do not run the digital outputs or
PID control outputs leads in the same wire bundle as any 120 vac
wires. Inputs leads should never be run in the same bundle with any
high power leads.
4. If E-M relays are required and must be in the same panel as the Watlow Anafaze equipment, use a .01 uF at 1000 vdc or higher vdc disk
capacitor in series with a 47 ohm 1/2 W resistor across the NO contacts of the relay load contacts. This is the most important step in suppressing RFI from relay contacts. This network is known as arc
suppressor or snubber networks.
5. Use of other voltage suppressing devices may also be used, but are
not normally required. A device known as a MOV rated at 130 vac
for 120 vac control circuits may be placed across the load. This will
limit the peak ac voltage to about 180 vac. A device known as a transorb (back to back zeners) may be used across the digital output. The
rating of 5 vdc should be used. This will limit the dc voltage to 5 vdc
on the digital output loop.
See diagrams for proper placement of the above devices. The parts for
RFI suppression are available from Watlow Anafaze.
16 8LS User’s Guide
Installation
g
The above steps should eliminate any noise problems that might be
present with using E-M relays. If, problems persists and/or any
questions about the above steps arises, please call Watlow Anafaze
Technical Service Department at (408) 724 3800.
L 1
8LS
-
+
.01uf
1000 VDC
or higher
K1
NO
NC
47 ohm
1/2 W
120 VAC
-
SSR
+
5 V Transorb
L 2
K1
HORN
MOV
130 VAC ratin
8LS User’s Guide 17
Installation
Terminal Block And Connector Layout
The 8LS terminal blocks and connectors are assigned according to the
following two pages. Subsequent sections provide detailed connection
descriptions.
Communications Terminal Block 4
Jumper*
Analog
Ana In 1-
Ana In 2-
Ana In 3-
Ana In 4-
Ana in 5-
Ana in 6-
Ana In 7-
Ana in 8-
Analog
Dig In 10
Logic
COM
COM
COM
Chas Gnd
Term inal
Block 1
2
4
6
8
10
12
14
16
18
20
22
24
1
3
5
7
9
11
13
15
17
19
21
23
Rx- Rx+ Tx- Tx+
6
5
COM
Rx
Analog
COM
Ana In 1+
Ana In 2+
Ana In 3+
Ana In 4+
Ana In 5+
Ana In 6+
Ana In 7+
Ana In 8+
Analog
COM
Dig In 9
Dig In 11
COM
50 Pin
Conn
RS-485 Connections
1234
SHLD
Tx
RS-232 Connections
Termina l
Block 2
10
12
14
16
18
20
22
24
1
2
3
4
5
6
7
8
9
11
13
15
17
19
21
23
PID 1 Out +
4950
R
PID 3 Out +
PID 4 Out +
PID 6 Out +
I
PID 7 Out +
B
B
O
N
Pulse In +
Dig In 12
Dig Out 1
Dig Out 2
Dig Out 3
Dig Out 4
12
Global
COM
Logic
+ PID 2 Out
COM
Logic
+ PID 5 Out
COM
Logic
+ PID 8 Out
COM
Logic
COM
Logic
COM
Logic
+5 Vdc
+5 Vdc
Alarm Out
* It is suggested with noisy electrical environments, a heavy gauge jumper wire be connected between the chassis ground and shield terminals on the rear terminal block as
shown.
18 8LS User’s Guide
Terminal block 3
1
Chas
Gnd
23
AC AC
Neutral
HOT
(green) (white) (black)
Red marker on flat ribbon cable
RTB Connections
Installation
The RTB provides the control outputs and additional digital inputs and
outputs as follows:
Terminal Function Terminal Function
1 +5 Vdc 2 +5 Vdc
3 Logic COM 4 Logic COM
5 Spare 6 Spare
7 Spare 8 Spare
9 PID 1 Out 10 Dig 30 Out
11 PID 2 Out 12 Dig 29 Out
13 PID 3 Out 14 Dig 28 Out
15 PID 4 Out 16 Dig 27 Out
17 PID 5 Out 18 Dig 26 Out
19 PID 6 Out 20 Dig 25 Out
21 PID 7 Out 22 Dig 24 Out
23 PID 8 Out 24 Dig 23 Out
25 Dig 5 Out 26 Dig 22 Out
27 Dig 6 Out 28 Dig 21 Out
29 Dig 7 Out 30 Dig 20 Out
31 Dig 8 Out 32 Dig 19 Out
33 Dig 9 Out 34 Dig 18 Out
35 Dig 10 Out 36 Dig 17 Out
37 Dig 11 Out 38 Dig 16 Out
39 Dig 12 Out 40 Dig 15 Out
41 Dig 13 Out 42 Dig 14 Out
43 Dig 1 In 44 Dig 2 In
45 Dig 3 In 46 Dig 4 In
47 Dig 5 In 48 Dig 6 In
49 Dig 7 In 50 Dig 8 In
All digital outputs and the PID outputs on this ribbon connection are
Sink Outputs. They are in reference to the 5Vdc supply. The outputs will
be low when they are on.
All digital inputs are TTL level inputs and may be selected from
software if they will be high/false or low/true inputs.
8LS User’s Guide 19
Installation
Analog Inputs
NOTE
When using the RTB, proper polarity of the flat
ribbon cable is necessary for correct pin terminations. Install the red marker indicating pin #1 to
the left when terminal #1 of the RTB is to the left.
The flat ribbon cable should have the red marker
down when installing it on the back of the 8LS. To
confirm proper polarity, check that pin #1 is +5vdc
with respect to pin #3.
Connecting analog signals to the 8LS is normally straightforward. Most
thermocouples can be directly connected and mixed in any order. Other
types of analog signals such as RTD's or mAdc or Vdc require scaling
resistors installed on the 8LS inputs. Some problems may occur that
could reduce accuracy and possibly damage the unit. Below are some of
the potential areas for concern.
Common Mode Voltage
Common mode voltage is the voltage between the ground at the sensor
and the ground at the 8LS. It can be an AC or DC voltage and appears
equally at the high and low input terminals. Frequently it is caused by
large currents flowing in the ground path between the 8LS and the
sensors. Use isolated sensors or ungrounded thermocouples and locate
the 8LS as close as possible to the sensors in order to minimize the
effects. Do not exceed the maximum common mode voltage of 175 Vac.
Normal Mode Voltage
Normal mode voltage appears across the terminals of the input and is
the signal from the sensor plus any undesirable noise. The major cause
of this noise is AC power line pick-up. The effects are reduced by the
8LS capacity to integrate the signal over a multiple of the power line
frequency. Further reduction can be achieved by locating the 8LS near
the sensors and by using twisted and shielded sensor wires.
To ensure accurate readings, the maximum of normal mode plus signal
should not exceed -10mv to +60mv.
Grounding
For best accuracy, observe the grounding recommendations for
connecting each input and output signal. The analog signal grounds
should be connected to the analog ground terminals. The
communication and control outputs should be connected to their
respective grounds. Do not mix the grounds or connect them together. If
possible, route the analog signal cables separately from the
communication, control and power cables.
20 8LS User’s Guide
Input Scaling
g
Installation
Source Impedance
Each sensor has a certain output impedance which is effectively
connected across the 8LS input amplifier when a measurement is made.
To reach the rated accuracy, the maximum source impedance should not
exceed 500 ohms. Consult Watlow Anafaze for operation with higher
source impedance.
The 8LS contains an area that can be used to install resistors to scale
input voltages and convert milliamp inputs to match the -10 to 60mv (-
16.7% to 100%) input range. The input circuit is designed to enable
connection of current inputs (such as 4 to 20ma), voltage inputs, and 3Wire RTD. Watlow Anafaze will supply input scaling as needed -- order
option 8LS-SI-XX. The input circuit is shown below:
Ana In + = Analog signal + input
Ana In - = Analog signal - input
Ana Gnd = Analog signal ground
Terminal
Block
Ana In
Ana In
Ana Gnd
+
-
RA
+10 Vdc Reference
RC
RB
RD
RB Alternate
+
IN
Measurement
Input
-
IN
Ground
Analo
RA is shorted by a jumper on the PC board, REMOVE THIS JUMPER
TO INSTALL RA.
Resistors should be 0.1% metal film, 1/4 watt. Note that the resistors
must be stood on end due to the compact size of the unit. Other
components such as capacitors can be installed for signal conditioning.
Please consult Watlow Anafaze. The PC board silk screen shows the
resistor locations.
8LS User’s Guide 21
Installation
Resistor Installation
For scaling resistors the body of the resistor goes vertically into the hole
with the white silk screen. The lead on the top then goes into the
adjacent indicated hole. The resistor positions are highlighted.
RC1
RB1
RC2
RB2
RC3
RB3
RC4
RB4
RC5
RB5
RC6
RB6
RC7
RB7
RC8
RB8
RD1
RA1
RD2
RA2
RD3
RA3
RD4
RA4
RD5
RA5
RD6
RA6
RD7
RA7
RD8
RA8
22 8LS User’s Guide
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