Echelon LonPoint Application and Plug-In User Manual

Download

LonPoint Application

and Plug-in Guide

9HUVLRQ





&RUSRUDWLRQ

$

(FKHORQ/21/21:25.6/RQ7DON1HXURQ/210$5. /RQ3RLQW6FKHGXOH0DNHU6FKHGXOH.HHSHUWKH/RQ8VHUVORJRWKH (FKHORQORJRDQGWKH/210$5.ORJRDUHUHJLVWHUHGWUDGHPDUNVRI (FKHORQ&RUSRUDWLRQ/RQ3RLQWWKH/RQ3RLQW6FKHGXOH0DNHU/RQ0DNHU DQG/RQ6XSSRUWDUHWUDGHPDUNVRI(FKHORQ&RUSRUDWLRQ

2WKHUEUDQGDQGSURGXFWQDPHVDUHWUDGHPDUNVRUUHJLVWHUHGWUDGHPDUNV RIWKHLUUHVSHFWLYHKROGHUV

1HXURQ

&KLSV/RQ3RLQW0RGXOHVDQGRWKHU2(03URGXFWVZHUHQRW

GHVLJQHGIRUXVHLQHTXLSPHQWRUV\VWHPVZKLFKLQYROYHGDQJHUWRKXPDQ KHDOWKRUVDIHW\RUDULVNRISURSHUW\GDPDJHDQG(FKHORQDVVXPHVQR UHVSRQVLELOLW\RUOLDELOLW\IRUXVHRIWKH1HXURQ

&KLSVRU/RQ3RLQW0RGXOHVLQ

VXFKDSSOLFDWLRQV

3DUWVPDQXIDFWXUHGE\YHQGRUVRWKHUWKDQ(FKHORQDQGUHIHUHQFHGLQWKLV GRFXPHQWKDYHEHHQGHVFULEHGIRULOOXVW U DWLYHSXUSRVHVRQO\DQGPD\QRW KDYHEHHQWHVW H GE\(FKHORQ,WLVWKHUHVSRQVLELOLW\RIWKHFXVWRPHUWR GHWHUPLQHWKHVXLWDELOLW\RIWKHVHSDUWVIRUHDFKDSSOLFDWLRQ

(&+(/210$.(6$1'<285(&(,9(12:$55$17,(625&21',7,216 (;35(66,03/,('67$78725<25,1$1<&20081,&$7,21:,7+<28$1' (&+(/2163(&,),&$//<',6&/$,06$1<,03/,(':$55$17<2) 0(5&+$17$%,/,7<25),71(66)25$3$57,&8/$5385326(

1RSDUWRIWKLVSXEOLFDWLRQPD\EHUHSURGXFHGVWRUHGLQDUHWULHYDOV\VWHP RUWUDQVPLWWHGLQDQ\IRUPRUE\DQ\PHDQVHOHFWURQLFPHFKDQLFDO SKRWRFRS\LQJUHFRUGLQJRURWKHUZLVHZLWKRXWWKHSULRUZULWWHQSHUPLVVLRQ RI(FKHORQ&RUSRUDWLRQ

3ULQWHGLQWKH8QLWHG6WDWHVRI$PHULFD &RS\ULJKWE\(FKHORQ&RUSRUDWLRQ

(FKHORQ&RUSRUDWLRQ 0LUDQGD$YHQXH 3DOR$OWR&$86$

iii

1 LonPoint System Overview 1-1

Introduction to the LonPoint System 1-2 Getting Started 1-4 LonPoint Applications 1-4 Terminology Used in this Manual 1-6

Upstream and Downstream 1-6 Heartbeats 1-6 Throttle 1-7 Default Values 1-7 Override Values 1-7 Network Variables 1-8

Changing Network Variable Types 1-9 Network Variable Formats 1-10 Changing Network Variable Formats 1-10

2 The Digital Input Functional Block 2-1

The Digital Input Functional Block 2-2 Configuring the Digital Input with the LonPoint Plug-in 2-2

Digital Input 2-3 Status 2-6

3 The Digital Input/Counter Functional Block 3-1

The Digital Input/Counter Functional Block 3-2 Configuring the Digital Input/Counter with the LonPoint Plug-in 3-2

Digital Input/Counter 3-3

Processing Options 3-4

Using The Control Network Variable 3-8 Processing Parameters 3-9 Translation 3-10 Output Parameters 3-11 Status 3-12

4 The Digital Output Functional Block 4-1

The Digital Output Functional Block 4-2 Configuring a Digital Output with the LonPoint Plug-in 4-2

Digital Output 4-3 Input Defaults 4-6 Presets 4-7 Output Parameters 4-8 Heartbeats 4-9 Status 4-10

5 The Digital Encoder Functional Block 5-1

The Digital Encoder Functional Block 5-2 Configuring the Digital Encoder with the LonPoint Plug-in 5-2

Digital Encoder 5-3

The LonPoint Application and Plug-in Guide

Lookup Tables 5-4 Heartbeats 5-7 Status 5-8

6 The Analog Input Functional Block 6-1

The Analog Input Functional Block 6-2 Configuring an Analog Input with the LonPoint Plug-in 6-2

Analog Input 6-3 Translation 6-5 Output Parameters 6-6 Status 6-7

Analog Input Gain and Current Settings 6-7

Amps Measurement Type (2WIR and 4WIR Jumper Settings) 6-7 Ohms Measurement Type (RES Jumper Setting) 6-7 Volts Measurement Type (VOLT Jumper Setting) 6-8

7 The Analog Output Functional Block 7-1

The Analog Output Functional Block 7-2 Configuring an Analog Output 7-2

Analog Output 7-3 Defaults 7-4 Presets 7-5 Heartbeats 7-6 Status 7-6

8 The Analog Function Block (AFB) Functional Block 8-1

The Analog Function Block (AFB) Functional Block 8-2 Configuring the AFB Functional Block using the LonPoint Plug-in 8-2

Analog Function Block 8-3 Inputs 8-4 Function 8-6 Outputs 8-8 Heartbeats 8-10 Status 8-11

9 The PID Controller Functional Block 9-1

The PID Controller Functional Block 9-2 Configuring a PID Controller with the LonPoint Plug-in 9-3

PID 9-4 Input Defaults 9-5 Presets 9-6 PID Coefficients 9-7 Output Parameters 9-9 Heartbeats 9-11 Status 9-12 LonPoint PID Controller Tuning 9-12

Table of Contents

10 The Scheduler Functional Block 10-1

Using the SCH-10 Scheduler Module 10-2

SCH-10 Functional Blocks 10-2 LonPoint Schedule Maker 10-4 Types of Schedules 10-5

Overview of the Supervisory Application Development Process 10-5 Creating an Event Schedule Design 10-6

Defining Daily Schedules 10-6 Assigning Default Daily Schedules 10-7 Assigning Override Daily Schedules 10-8

Creating a State Machine Design 10-9

Defining Inputs and Outputs 10-9 Drawing a State Machine Bubble Diagram 10-13

Defining State Transitions 10-15

Defining Exit Conditions 10-18

Starting and Exiting the LonPoint Schedule Maker Utility 10-19 Configuring the Real Time Clock Functional Block 10-20 Configuring the Event Scheduler Functional Block 10-21

Configuring Daily Schedules 10-22 Configuring Default Daily Schedules 10-23

Configuring Override Daily Schedules 10-24 Configuring the State Machine Functional Block 10-25

Configuring a Digital Output Schedule 10-25 Configuring a State Machine 10-26

Assigning Input/Output Names 10-26

Defining the State Machine 10-29

Defining Exit Conditions 10-31

Setting Scheduler Options 10-33 Saving and Loading a Supervisory Application Design File 10-34 Simulating a Supervisory Application Design 10-35

Resetting the Simulator 10-37 Using Debug Mode 10-37 Simulating Inputs 10-38 Running to the Next Event 10-38 Manually Entering Time and Date 10-39 Overriding the Event Schedule 10-39

Adding the Scheduler Functional Blocks 10-40 Downloading a Supervisory Application Design 10-41 Setting the SCH-10 Time 10-42 Changing the Mode and Mode_Out Types 10-42 Testing a Schedule Design 10-43

The LonPoint Application and Plug-in Guide

11 The Schedule Keeper Utility 11-1

The Schedule Keeper Utility 11-2

Starting the Schedule Keeper Utility 11-2 Modifying the Daily Schedules 11-3 Modifying the Daily Default Schedule 11-5 Modifying Schedule Overrides 11-6 Modifying System Parameters 11-7 Adding Schedule Constraints 11-8

Schedule Constraint Equations 11-9

The Schedule Constraint Language 11-10 Adding Parameter Constraints 11-11

System Parameter Constraint Equations 11-12

System Parameter Constraint Language 11-12 Saving and Exiting 11-13

Converting to US Units 11-13

12 The Type Translator Functional Block 12-1

The Type Translator Functional Block 12-2 Configuring a Type Translator Using the LonPoint Plug-in 12-2

Type Translator 12-3 Status 12-5

13 The Data Logger Functional Block 13-1

The Data Logger Functional Block 13-2 Configuring the Data Logger with the LonPoint Plug-in 13-3

Data Logger 13-3 Input Options 13-4 Input Limits 13-5 Log Options 13-6 Status 13-9

The LonPoint Data Logger Utility 13-9

Menu Commands 13-11 Formatting Preferences 13-12 Monitoring Preferences 13-13 Log Preferences 13-14 CSV Text File Format 13-16

Tagname Line 13-16

Data Lines 13-17

Data Point Formats 13-18 Command Line Switches 13-18 Setting the DL-10’s Real Time Clock 13-19

14 The Node Object Functional Block 14-1

The Node Object Functional Block 14-2 Configuring a Node Object with the LonPoint Plug-in 14-2

Node Object Window: Node Object 14-3 Status 14-4

Table of Contents

LonPoint System Overview

This chapter introduces the LonPoint System, applications, plug-in, and utilities.

The LonPoint Application and Plug-in Guide 1-1

Introduction to the LonPoint System

Chapter

The LonPoint System is a family of LONMARK® products used to integrate new and legacy devices, as well as other L systems. The LonPoint system product family includes the following:

• LonPoint Interface, Scheduler, Data Logger, and Router Modules. LONMARK

devices that provide I/O processing, application resources, scheduling, sequencing, data logging, and routing for a LonPoint system. The LonPoint interface, scheduler, and data logger modules are certified to meet the L Interoperability Guidelines.

• LonMaker for Windows Integration Tool. An LNS installation tool with a

Visio™ user interface that supports LonPoint devices, other L and other L

ONWORKS devices. You can use the LonMaker tool to design,

configure, commission, and maintain a distributed control network. The LonPoint Plug-in is included with the LonMaker tool to simplify LonPoint device configuration.

• LonPoint Plug-In. An LNS application that provides an easy-to-use interface for

configuring LonPoint devices. The plug-in can be called from any LNS tool that follows the LNS plug-in standard, including the LonMaker tool.

• LNS Server. The service provider for the LNS network operating system.

Provides a central database that can be used by multiple LonMaker tools, LonPoint Plug-ins, and other LNS applications simultaneously. The LNS Server may run on the same PC with the LonMaker tool and LonPoint Plug-in, or may run on a different PC. A remote LNS Server may be accessed over a LonWorks network, a local area network, or the Internet.

• LNS Network Interface Hardware. Hardware that allows you to connect a PC

running the LNS Server, the LonMaker tool, and the LonPoint Plug-in to a

ONWORKS network. This hardware is not necessary for network design, but

L must be installed to commission, test, or manage devices. The LNS network interfaces include the PCLTA-10 ISA card, the PCC-10 PC Card (PCMCIA compatible), the SLTA-10 Serial LonTalk Adapter, and the PCNSI ISA card.

ONMARK devices, to create interoperable control

ONMARK

ONMARK devices,

Each LonPoint device comes pre-loaded with application software that implements a number of functional blocks. These functional blocks are listed in Table 1.1. They are installed and interconnected using the LonMaker tool as described in the LonMaker for Windows User’s Guide. The functional blocks are then configured as described in this user’s guide.

Table 1.1 LonPoint Functional Blocks

Name Description Examples

2 Digital Input

(DI)

3 Digital

Input/Counter (DC)

4 Digital Output

(DO)

5 Digital

Encoder (DE)

Senses digital inputs Contact closure, push

button input, logic input Senses, counts, and times digital inputs

Turnstyle counting,

frequency measurement,

flow meter interface. Drives digital outputs Control relays, logic

outputs Performs logic functions on up to four digital inputs

Relay logic, interlocks,

Boolean logic, device

enables

1-2 LonPoint System Overview

6 Analog Input

Scheduler (ES)

LonPoint Device

Quantity per Device

(AI)

7 Analog Output

(AO)

8 Analog

Function Block (AFB)

9 PID Controller

(PID)

10/11 Real Time

Clock (RTC)

10/11 Event

10/11 State Machine

(SM)

12 Type

Translator

13 Data Logger Logs periodic data based

14 Node Object Management commands

The LonPoint functional blocks are loaded into the LonPoint devices as listed below.

Senses current, voltage, or resistance inputs

Drives current, voltage, or resistance analog outputs Performs functions on two analog values and a digital value such as add, subtract, multiply, divide, greater than, less than, enthalpy, and comparison Performs closed-loop control Maintains date, day of week, and time of day Schedules system events Scheduler with occupied

Controls system state Sequence of operations

Converts network variable data types

on exceptional data values or large changes in data value.

for a device

Measure temperature,

pressure, humidity,

velocity, level

Variable speed drive

control; valve control;

damper control

Deadband thermostat,

heating/cooling

optimization

Pressure, temperature, or

position loops

Non-volatile system time

source

and unoccupied periods,

daily, weekly, holiday

schedules

controller

Interface between

incompatible devices

Logging periods of

extreme

temperature/rapid

fluctuations.

Putting devices into

Override. Getting device

status.

The LonPoint Application and Plug-in Guide 1-3

Table 1.2 Assignment of LonPoint Functional Blocks to LonPoint Devices

Functional Block

DI-10 Node Object

Digital Input Digital Encoder Analog Function Block Type Translator

DO-10 Node Object

Digital Output Digital Encoder Analog Function Block Type Translator

DIO-10 Node Object

Digital Input/Counter Digital Output Digital Encoder Analog Function Block

1 4 2 4 6 1 4 2 2 6 1 2 2 2 2

Type Translator 6

AI-10 Node Object

Analog Input Digital Encoder Analog Function Block Type Translator

AO-10 Node Object

Analog Output PID Controller Digital Encoder Analog Function Block

Type Translator SCH-10 (with SCH-10 application)

SCH-10 (with DL10 application)

Each functional block has a number of network variables, through which data is passed to or from the functional block, and configuration properties, which are used to configure the functional block and define its behavior. The functional blocks are implemented as L the LonMaker tool using the LonPoint Plug-in and utilities.

Node Object

Real Time Clock

Event Generator

State Machine

Node Object

Data Logger

Real Time Clock

ONMARK objects on the LonPoint devices, and are configured from

1 2 2 4 4 1 2 2 1 2 2 1 1 1 1 1 1 1

Note:

The SCH-10 device ships with the SCH-10 application pre-loaded. The DL-10 application can be downloaded into the SCH-10 device with a network integration tool such as the LonMaker tool for Windows.

Getting Started

Install the LonPoint Plug-in software as described in the LonMaker for Windows User’s Guide. Create a network design that includes LonPoint devices and

functional blocks. To start the LonPoint Plug-in, right-click a LonPoint functional block and select

Configure from the shortcut menu. The LonPoint Plug-in window associated with the selected functional block opens.

LonPoint Applications

Each LonPoint device has a LonPoint Application. This is the application firmware in the device. All LonPoint devices are shipped with applications already loaded. The version of the application which shipped in the device is printed on the LonPoint device label. Newer versions of applications may become available and may be loaded into the LonPoint device at any time using an LNS tool such as the LonMaker tool (see Loading a New Application into a Device in Chapter 5 of the LonMaker for Windows User’s Guide).

1-4 LonPoint System Overview

The LonPoint AI-10, AO-10, DI-10, and DO-10 applications have been upgraded to version 3, but many of the devices currently available still have the version 2 applications loaded into them. The version 3 applications have been certified to meet

ONMARK Interoperability Guidelines. The program ID for all four applications

the L has been changed to indicate a L

ONMARK. The Digital Output, AFB, and PID

functional blocks have been enhanced in the version 3 applications as described in the LonPoint Read Me First document in the LonPoint program folder. Each functional block has an independent version number that is displayed on its

Status

tab. When you first install a LonPoint device in a network, you should upgrade it to

version 3 if it has a version 2 application. You do not have to upgrade devices that have already been installed.

Each application contains a program ID that identifies the class, subclass, model number, and application version. If an attempt is made to load an application into a device that currently contains an application with a different class or subclass, the LonMaker tool will issue an application load warning. The following table summarizes the program ID information for all version 2 and version 3 LonPoint applications:

Device

Version 2 Version 3

Application

DI-10 Device Class: 0532

Device Subclass: 8A04 Model Number: 02

ONMARK Certified: No

DO-10 Device Class: 0533

Device Subclass: 8A04 Model Number: 02

ONMARK Certified: No

AI-10 Device Class: 0518

Device Subclass: 8A04 Model Number: 02

ONMARK Certified: No

AO-10 Device Class: 0519

Device Subclass: 8A04 Model Number: 02

ONMARK Certified: No

SCH-10 Device Class: 0114

Device Subclass: 8A04 Model Number: 02

ONMARK Certified: No

DIO-10 No version 2 DIO-10

application available.

DL-10 No version 2 DL-10

application available.

Device Class: 052A Device Subclass: 8A04 Model Number: 03

LONMARK Certified: Yes

Device Class: 0533 Device Subclass: 8A04 Model Number: 03 LONMARK Certified: Yes

Device Class: 0518 Device Subclass: 8A04 Model Number: 03 LONMARK Certified: Yes

Device Class: 0519 Device Subclass: 8A04 Model Number: 03 LONMARK Certified: Yes

Device Class: 0114 Device Subclass: 8A04 Model Number: 03 LONMARK Certified: Yes

Device Class: 0528 Device Subclass: 8A04 Model Number: 03

LONMARK Certified: Yes

Device Class: 0104 Device Subclass: 8A04 Model Number: 03

The LonPoint Application and Plug-in Guide 1-5

The DI-10 device’s version 2 and version 3 applications have different Device Class values, so the LonMaker tool will issue a warning when an attempt is made to load a version 3 DI-10 application into a device which currently contains a version 2 DI-10 application. This warning may be safely ignored.

The SCH-10 device supports two applications, the SCH-10 application and the DL-10 application. Attempting to load the DL-10 application into a SCH-10 device which currently contains the SCH-10 application or vice versa will cause a warning in the LonMaker tool that an attempt is being made to load an application with a different Device Class or Device Subclass into a device already containing an application. In this case, this warning may be safely ignored.

Terminology Used in this Manual

The following sections contain definitions for several concepts presented in this manual in conjunction with the LonPoint functional blocks.

Upstream and Downstream

The terms upstream and downstream represent the flow of information. If functional block A sends information to functional block B, B is said to be downstream of A, and A is said to be upstream of B. For example, in the following figure, the DO- 1 Valve Actuator is downstream of the DI- 1 Limit Switch.

LONMARK Certified: Yes

Heartbeats

A heartbeat is a network variable update that is automatically sent if the network variable has not otherwise been updated for a configurable length of time.

Most LonPoint output network variables can be configured to send heartbeat updates. Most LonPoint input network variables can monitor heartbeats from upstream functional blocks to detect device failures using heartbeat receive checking. If a heartbeat is not received within the specified amount of time, the functional block will go into heartbeat failure and cease propagating output network variables, and if the functional block is associated with a hardware output it will cause that output to go to its configured default value. The functional block will return to normal operation once the heartbeat is restored.

The heartbeat send time should be approximately 4 times as frequent as the corresponding expected heartbeat receive time to allow for lost messages.

Heartbeat failure propagates downstream in a LonPoint system. Once a LonPoint functional block receives a heartbeat failure, it will stop sending heartbeats, causing

1-6 LonPoint System Overview

any downstream functional blocks that check heartbeats to go into heartbeat failure as well. Functional blocks which go into heartbeat failure will output their default values (see Defaults, below)

You can disable heartbeat receive checking on downstream functional blocks. This may be desirable in situations where it makes sense for the application to continue to use the last known valid data rather than change to the configured default network variable or hardware output.

Throttle

The throttle option limits the rate of updates on an output network variable. Use throttling to reduce network traffic. In order to minimize network traffic, set the throttle value to the longest interval between updates on the output network variable that is compatible with correct system operation. Turn off throttling by setting the value to 0. The AI and PID functional blocks produce data at their configured scan interval, and do not have a throttle configuration property.

Default Values

Default values are values that apply to hardware outputs and both input and output network variables.

A functional block will use its default hardware or network variable output value when any of the following conditions occur:

• The functional block has just come out of reset and has not yet received any

network variable updates.

• The functional block has an enable input network variable which is turned off.

• The functional block senses a heartbeat failure.

Default values for input network variables are used when any of the following conditions occur:

• The network variable has not yet received any updates since its last reset.

• The network variable is not connected. There are often situations where one or

more inputs on a functional block will not be connected. The network variable should be configured with an appropriate default input value. This also allows you to manually set the value of an input network variable for debugging and testing.

Override Values

Override values are values that apply to output network variables and hardware outputs. LonPoint functional blocks can be forced into an override state with the LonMaker tool or the LonPoint Plug-in. When a functional block is in the override state, the output network variables and hardware outputs, if any, will be set to their override values. Override values and the override state are preserved across power cycles and resets.

While override values are stored in both the device and in the LNS database, the override state of a device is stored only in the device, not in the LNS database. If you replace a device with the LonMaker tool, the old device’s override values are

The LonPoint Application and Plug-in Guide 1-7

transferred to the new device. The new device will not necessarily be in the same override state as the old device.

Network Variables

On the first tab of the LonPoint Plug-in window for each LonPoint functional block (except for the Node Object) there is a network variable shape for each network variable which looks like this:

To get information about a network variable, click on the network variable shape. The following

Network Variable Information dialog appears:

This dialog contains the following information: Network Variable Name The name of the network variable. You can change this

name using the LonMaker tool.

Type Name The network variable type. If the type is a standard

network variable type, the network variable may only be connected to network variables with the same type. If the network variable has a changeable type, the

Type button will be enabled.

Format Name The network variable format. The format determines

how data from the network variable will be formatted when it is displayed or input by an LNS tool such as the LonMaker tool. If the format is changeable, the

Format button will be enabled.

Units The type of units the network variable uses. If the

network variable does not use a specific type of unit, this field will be empty.

To change a network variable type, click the network variable format, click the

Change Format button.

Change Type button. To change a

Change

1-8 LonPoint System Overview

Changing Network Variable Types

You can change the types of some network variables in LonPoint functional blocks. Most changeable types are either floating-point or enumerated network variables, as well as the network variables in the Type Translator functional block.

Changing the type of a network variable will reset its format to the default for that type. This affects the display of related fields in the LonPoint Plug-in. See Network Variable Formats for more information.

To change the type of a network variable, click the network variable shape in the LonPoint Plug-in window, then click the

Variable Information dialog. The following Change Network Variable Type

dialog appears:

Change Type button in the Network

This dialog contains the following fields: Network Variable Name The name of the network variable. This field is read-only.

You can change the name of a network variable using the LonMaker tool.

Previous Type Name The current network variable type. This field is read-

only.

Standard Network Variable Type

Type Files Lists all available type files from the device resource file

Specifies whether the new network variable type is a standard type or a user defined type. Enable this option if you want to use a SNVT. (See the SNVT Master list in the LNS Utilities and L Disable this option if you want to select a user-defined type.

catalog. If the Standard Network Variable Type option is selected, only the standard type file is listed. Select the

ONMARK Reference help file.)

The LonPoint Application and Plug-in Guide 1-9

type file containing the new network variable type from this list.

Type List Lists all network variable types in the selected file that

are compatible with the selected network variable. Select the new network variable type from this list.

Compatible Types Indicates how compatibility is decided. For all functional

blocks except the Type Translator, this is by (e.g., floating-point or enumeration). The Type Translator uses the equal to four bytes long. You cannot change this option.

Length <= option, listing all types less than or

Base Type

Network Variable Formats

Many floating-point network variable types have at least two standard formats: one for SI units (i.e. the metric system, which are the default units of most SNVTs), and one for comparable U.S. units. There may also be more than one format for either of these two basic systems (e.g. SNVT_flow has U.S. formats for both gallons per second and cubic feet per minute). If there is more than one format, one of them is considered the default. The LonMaker and LonPoint Plug-in installation programs allow installing format files that have either all SI units as the default, or all U.S. units as the default.

Selecting a format does not affect the actual network variable data on the network or configuration property data in the device. This data is always in the native units of the network variable or configuration property. The format only affects how the data is displayed (or interpreted when doing data entry). Any format that does not use the native configuration property or network variable units will convert the data to or from the native units using conversion values associated with that format. For example, if U.S. units are being used, data being entered is converted internally to SI units, and converted back to U.S. units for display. Due to floating-point rounding, values displayed may not always be exactly what was entered.

Changing Network Variable Formats

You can change the format of most LonPoint floating-point network variables, as well as the network variables in the Type Translator functional block.

Note:

Changing the format of a network variable affects the display of related fields in the LonPoint Plug-in, the LonMaker tool, and other third-party LNS applications. The format change will be immediately visible in the LonPoint plug-in. However, other applications may not reflect the format change until some action causes the format to be refreshed; this can be accomplished by restarting the application or by some explicit command, such as the LonMaker Browser's

To change a network variable format, click the network variable shape in the LonPoint Plug-in window, then click the

Information dialog. The following Change Network Variable Format dialog

appears:

1-10 LonPoint System Overview

Refresh All command.

Change Format button in the Network Variable

This dialog contains the following fields:

Network Variable Name The name of the network variable. This field is read-only.

You can change the name of a network variable using the LonMaker tool.

Previous Format The current format of the selected network variable. This

field is read-only.

Format Lists the available formats for the selected network

variable type. Select a format from this list to explicitly determine the type of units used in the selected network variable and its associated configuration properties.

Use Default Automatically selects the default format from the Format

field. Use this option to reset a network variable to use its default format.

When you select a new format for a network variable, the units of that format will be indicated in the LonPoint Plug-in anywhere there is a field which contains data that matches the network variable type (e.g. an override value). Data in these fields is entered and displayed in those units.

The LonPoint Application and Plug-in Guide 1-11

1-12 LonPoint System Overview

The Digital Input Functional

Block: Application and Plug-in

This chapter describes how to configure a Digital Input functional block using the LonPoint Plug-in.

The LonPoint Application and Plug-in Guide 2-1

The Digital Input Functional Block

The Digital Input functional block reads the state of a digital signal. This value is then processed, and the resulting digital value is sent to the output network variable. The following figure and table summarize the inputs and outputs of the Digital Input functional block:

Output Network Variables

Default name Default type Description

Digital SNVT_switch The Digital output network

variable driven by the sensor.

Configuring the Digital Input with the LonPoint Plug-in

Right-click a Digital Input functional block and select Configure from the shortcut menu to open the Digital Input window of the LonPoint Plug-in. You can also choose Plug-ins from the shortcut menu and then select

LonPoint Object from the dialog box. The Digital Input functional block

window has two tabs,

Digital Input and Status.

Configure

2-2 Digital Input Functional Block

Digital Input

The Digital Input tab, pictured below, provides a graphical interface to the LonPoint Digital Input (DI) functional block. It allows you to determine how data from a physical digital input is interpreted and what value is sent over the network on the DI functional block’s output network variable.

The data flow in this tab is left to right. The raw digital input signal can be modified by the debounce configuration property, then passed to the configurable inversion function, then that data is passed to the remaining processing steps.

Use the plug-in to set the following configuration properties: Debounce The debounce time for the digital input. This is the

amount of time, in milliseconds, that the input must remain constant for the value to be passed on to the rest of the functional block. Set this value to 0 to turn off the debounce function.

Invert Specifies whether or not the data from the digital

input is inverted before further processing is done.

Location The location string for this digital input. This

property can be used to document the associated sensor’s location within the plant so it can be easily

The LonPoint Application and Plug-in Guide 2-3

found. This field may contain up to 30 characters. This value is separate from the device’s location property.

Processing Affects the translation of incoming data to the value

passed to the output network variable. There are five processing options:

Pulsed, and One-Shot.

Direct option causes data to be output directly

The after the debounce and invert functions have executed.

Delayed option specifies a delay from a change

The on the input to an update on the output network variable. A change from Off to On is delayed by the time indicated in the change from On to Off is delayed by the time indicated in the

Toggled option causes the output data to toggle,

The or change state, every time the input data changes from Off to On. For example, if a Digital Input functional block is attached to a push button and the functional block is configured with the option, the network variable output value will change every time the button is pushed.

Direct, Delayed, Toggled,

On Delay Time field. A

Off Delay Time field.

Toggled

Pulsed option generates a pulse on the output

The network variable every time the input data changes from Off to On. The pulse is generated after a delay specified on the of the pulse is specified on the does not matter how long the input data remains on, the output will always send a pulse of the specified length after waiting the configured delay. If a delayed pulse is re-triggered during a pulse, the delay will be ignored. If a pulse is re-triggered during a delay, the trigger will be ignored.

One-Shot option generates a pulse on the output

The network variable every time the input data changes from Off to On. The pulse is generated after a delay specified on the of the pulse is specified in the the input data changes from Off to On while the pulse is being sent, the pulse timer will be reset (i.e., if a two second pulse was retriggered after one second, the output would be on for two more seconds, or three seconds total).

On Delay Time Use this field with the

Shot Processing options. This value determines the

length of the delay in the change from the off state to the on state. To change the value, click the to the right of the time value to be changed and enter

On Delay Time field. The duration

Pulse Time field. It

Pulse Time field. If

Delayed, Pulsed, and One-

button

2-4 Digital Input Functional Block

the new values to be used for the delay. The valid range for this value is from zero to 48 days, 23 hours, 59 minutes, 59 seconds, and 999 milliseconds.

Off Delay Time Use this field with the

This value determines the length of the delay in the change from the on state to the off state. To change the value, click the value to be changed and enter the new values to be used for the delay. The valid range for this value is from zero to 48 days, 23 hours, 59 minutes, 59 seconds, and 999 milliseconds.

Pulse Time If you select either the

Processing options, the Pulse Time field appears

in place of the length of time the on state remains active. To change the value, click the the time value to be changed and enter the new values to be used for the pulse. The valid range for this value is from zero to 48 days, 23 hours, 59 minutes, 59 seconds, and 999 milliseconds.

Override Value Determines the value sent to the network via the

output network variable if the functional block is put into override mode as described in the next section.

Heartbeat Determines how often the functional block sends a

heartbeat over the network. The behavior of the system in case of a missed heartbeat is determined by the functional blocks which fail to receive the heartbeat. Setting this property to 0 disables the heartbeat for this functional block. Disabling the heartbeat causes the output network variable to only be transmitted in response to a changed input value.

Off Delay Time. This value determines

Delayed Processing option.

button to the right of the time

Pulsed or the One-Shot

button to the right of

Throttle Limits how often data is sent over the network.

Setting this property to 0 disables throttling.

The LonPoint Application and Plug-in Guide 2-5

Status

This tab allows you to view and change the status of a Digital Input functional block. This tab appears as follows:

This tab contains the following fields and buttons: Device Version The version number of the application in this device.

The minor version number (after the decimal point) is always read from the device itself. If the network is unattached or Offnet, the minor version number will

XX (e.g. 2.XX).

read

Error Log The most recently logged error on the device. This

error may not apply to the functional block you are configuring.

Error Description A description of the most recently logged error. Clear (Device Status) Clears the status of the device, including the Error

Log. This also clears other device communication statistics information that is not displayed here (e.g., Lost Messages). If you wish to examine the other information before clearing it, use the Test command described under Managing Devices, Functional

2-6 Digital Input Functional Block

Blocks, and Routers in the LonMaker for Windows User’s Guide.

Object Version The version number of this functional block. The

minor version number (after the decimal point) is always read from the device itself. If the network is unattached or Offnet, the minor version number will

XX (e.g. 2.XX).

read

Disabled Indicates

it is enabled, and communication with the device. If you can communicate with the device, you can change the state of the functional block by clicking the and Disable buttons. See Managing Devices,

Functional Blocks, and Routers in the LonMaker for Windows User’s Guide for more information.

Override Indicates

No if it is not in override, and ? if the plug-in is not in

communication with the device. If you can communicate with the device, you can change the mode of the functional block by clicking the

Override Off and Override On buttons. See

Managing Devices, Functional Blocks, and Routers in the LonMaker for Windows User’s Guide for more information.

Other Status Displays other information relating to the functional

block status (e.g. communication error, range error).

Clear (Object Status) Clears the status of the functional block.

Refresh Refreshes the information in this tab. Any changes to

the data displayed in this tab since the plug-in was started (by using the LonMaker tool’s Manage command, for example) will not be updated until this button is pressed. Some LonPoint plug-ins can experience a temporary lock-out. This can be cleared by clicking this button.

Yes if this functional block is disabled, No if

? if the plug-in is not in

Enable

Yes if this functional block is in override,

The LonPoint Application and Plug-in Guide 2-7

2-8 Digital Input Functional Block

The Digital Input/Counter

Functional Block: Application

and Plug-in

This chapter describes how to configure a Digital Input/Counter functional block using the LonPoint Plug-in.

The LonPoint Application and Plug-in Guide 3-1

The Digital Input/Counter Functional Block

The Digital Input/Counter functional block reads the state of a digital signal. This value is then processed, and the resulting value is sent to the digital output network variable. The Digital Input/Counter is a superset of the Digital Input; it contains all the functionality of the Digital Input plus additional capabilities. The following figure and tables summarize the inputs and outputs of the Digital Input/Counter functional block:

Input Network Variables

Default name Default type Description

Control

Default name Default type Description

Digital

Analog

This functional block contains an analog output network variable which is used for several different purposes depending on the processing option, and a control input network variable which may be used to clear, hold, pause, or preset the analog output. The digital output network variable type is always The analog output network variable type is changeable. See Chapter 1 for a discussion of network variables.

UNVT_

count_control

(changeable)

Output Network Variables

SNVT_switch

SNVT_temp_f

(changeable)

The Control network variable is an enumerated type that controls counting functions.

The Digital output network variable. The meaning varies according to the processing option. See the Processing Options, later in this chapter, for more information.

The Analog output network variable. The meaning varies according to the processing option. See the Processing Options, later in this chapter, for more information.

SNVT_switch.

Configuring the Digital Input/Counter with the LonPoint Plug-in

Right-click a Digital Input/Counter functional block and select Configure from the shortcut menu to open the Digital Input/Counter window of the LonPoint Plug-in. The Digital Input/Counter functional block window contains the

3-2 Digital Input/Counter Functional Block

following tabs, Digital Input/Counter, Processing Parameters,

Translation, Output Parameters, and Status.

Digital Input/Counter

The Digital Input/Counter tab, pictured below, provides a graphical interface to the LonPoint Digital Input/Counter (DC) functional block. It allows the user to determine how data from a hardware digital input is interpreted and what value is sent over the network on the Digital Input/Counter functional block’s output network variables.

The data flow in this tab is left to right. The raw digital input signal is checked against the input voltage threshold in order to determine the logical state of the input (on or off) and then can be modified by the debounce configuration property, then passed to the configurable inversion function, then passed to the remaining processing steps. Click the

variable buttons to change the types of these network variables. Use the plug-in to set the following configuration properties: Input Type Determines the voltage threshold levels which trigger

a state change. The value may of Dry Contact, 5V, 12V, 24V, or 31V. Use Dry Contact to determine if a relay or switch has been closed.

Debounce The debounce time for the digital input. This is the

amount of time, in milliseconds, that the input must

Control and Analog Output network

The LonPoint Application and Plug-in Guide 3-3

remain constant for the value to be passed on to the rest of the functional block. Set this value to 0 to turn off the debounce function.

Inversion Specifies whether or not the data from the digital

input is inverted before further processing is done. Determines whether a high voltage level is interpreted as an On state (not inverted) or an Off state (inverted).

Processing Affects the translation of incoming data to the value

passed to one of the output network variables. There are nine processing options:

Toggled, Pulsed, One-Shot, Count, Repeating Count, On Time, and Frequency. The Direct, Delayed, Toggled, Pulsed, and One-Shot options

cause the Digital input/Counter functional block to behave identically to the Digital Input functional block, and the Control and Analog output network variables will not be used. See Processing Options in the next section for a description of the processing options.

Location The location string for this digital input/counter. This

property can be used to document the associated hardware’s location within an installation so it can be easily found. This field may contain up to 30 characters. This value is separate from the device’s location property.

Direct, Delayed,

Processing Options

The following sections describe the processing options selected in the Digital Input/Counter tab.

Direct

Causes data to be output directly to the digital output network variable after the debounce and invert functions have executed.

Delayed

Specifies a delay from a change on the input to an update on the digital output network variable. A change from Off to On is delayed by the time indicated in

On Delay Time field. A change from On to Off is delayed by the time

the indicated in the

Off Delay Time field.

Toggled

Causes the digital output network variable value to toggle, or change state, every time the input data changes from Off to On. For example, if a Digital Input/Counter functional block is attached to a push button and the functional

3-4 Digital Input/Counter Functional Block

block is configured with the Toggled option, the digital network variable output value will change every time the button is pushed.

Pulsed

Generates a pulse on the digital output network variable every time the input data changes from Off to On. The pulse is generated after a delay specified on the

On Delay Time field. The duration of the pulse is specified on the Pulse Time

field. It does not matter how long the input data remains on, or if the input transitions from Off to On again during the pulse, the output will always send a pulse of the specified length after waiting the configured delay.

One-Shot

Generates a pulse on the output network variable every time the input data changes from Off to On. The pulse is generated after a delay specified on the

Delay Time field. The duration of the pulse is specified in the Pulse Time field.

If the input data changes from Off to On while the pulse is being sent, the pulse timer will be reset (i.e., if a two second pulse was retriggered after one second, the output would be on for two more seconds, or three seconds total). If a delayed pulse is re-triggered during a pulse, the delay will be ignored. If a pulse is retriggered during a delay, the trigger will be ignored.

Count

Counts Off to On transitions. When the hardware detects an input change from off-to-on, an internal counter is incremented. The count value is processed and sent to the Analog network variable. An appropriate network variable type for the Analog output network variable in this mode is network variable governs processing of the count as described in Using The Control Network Variable, later in this chapter. The input is sampled and the Digital network variable updated at 500ms intervals. The maximum number of events that can be counted is 16,777,215.

The count values are kept in RAM. The count is copied to non-volatile EEPROM once per day just past midnight as determined by the DIO-10 node object, whenever the node is sent offline, and whenever the functional block is commanded to go to the disabled state.

Power cycles, hard-resets, soft-resets, or watchdog timeouts will lose the RAM count values. After recovery from any of these events the last count stored in EEPROM will be loaded into the RAM counter.

If the hardware input has been configured for Dry Contact, the input may be configured to be debounced with a configurable time period. If the hardware input has been configured for voltage input (5V, 12V, 24V, or 32V) debounce is not supported.

The maximum input frequency when configured for count processing is dependent on the input hardware configuration as follows:

SNVT_count_f. The Control

The LonPoint Application and Plug-in Guide 3-5

DRY_CONTACT:

minimum period = min(500ms, 2 * debounce interval) maximum frequency = 1/minimum period

5V, 12V, 24V, or 32V :

maximum frequency = 20kHz

Repeating Count

Counts the off to on transitions from zero up to a configurable value called the terminal count. When the Digital Input/Counter reaches the terminal count the count is reset to zero. For example, a terminal count of 4 would produce values of zero, one, two, three, zero, one, two, three, … on the variable (an appropriate network variable type for the

variable in this mode is The Digital Input/Counter signals that it has reached the terminal count by

asserting the on until the

Digital network variable. The Digital network variable stays

Control network variable is set to CLEAR.

SNVT_count_f).

Analog output network Analog output network

Control network variable is not connected, the Repeating Count

If the processing will free-run and count repeatedly from zero to terminal count –1 on

Analog network variable. In this case the maximum input frequency is

the dependent on input hardware configuration as follows:

DRY_CONTACT:

minimum period = min(500ms, 2 * debounce interval) maximum frequency = 1/minimum period

5V, 12V, 24V, or 32V :

maximum frequency = 20kHz

Control network variable is connected, the Repeating Count maximum

If the input frequency is dependent on the time between the going to On and downstream logic setting the

CLEAR for a short enough time period such that the count function does not reach

the terminal count a second time.

Control network variable to

Digital network variable

Repeating count example:

A canning application needs to determine when four cans have passed down a chute to tell a downstream boxing machine to package the cans. The boxing machine indicates when it has completed its task. On the Digital Input/Counter, select Repeating Count mode, set the terminal count to four, and the Default Input for the reset the count is set to 0, as cans go by, the count reported by the network variable goes; 0, 1, 2, 3, then, on the arrival of the next can, the Digital

Control network variable to RUN via the LonPoint Plug-in. After

Analog

3-6 Digital Input/Counter Functional Block

output goes On and the count as reported by the Analog network variable is set to 0. Cans continue: 1, 2…, then, some downstream device controlling the boxing process sees the Digital network variable to be on, boxes the cans, and sends

CLEAR to the Control network variable. The digital output goes Off. Cans

continue three, zero and the process repeats. There are no race conditions, however there is a performance requirement – the

Control network variable must be cleared before the terminal count is reached a second time in order to get a new signal. If the Control network variable is not cleared before the terminal count is reached, counting will continue between zero and the terminal count, the Digital network variable will remain on, and the overrange bit of the object status for the Digital Input/Counter function block will be set. This status bit can be used as an indicator that the control loop is not being closed. If the Control network variable is not connected, the overrange status bit will not be set.

It is good design practice for the output network variable that updates the Control input network variable to have a send heartbeat so that the loop works even if some messages are lost.

Control TC

Can Counter

Analog

LoadBox FB

Boxing Machine

D1 Index

DE- 1

On-Time

Measures the accumulated on-time of the hardware input. A typical application for this mode is monitoring equipment usage time in order to determine when maintenance is due. Each half-second, an internal counter is incremented if the input is on. The count value is processed and sent to the Analog network variable (an appropriate network variable type for the Analog output network variable in this mode is SNVT_time_f; the units are seconds). The Control network variable governs processing. The input is sampled and the Digital network variable is updated at 500ms intervals.

The maximum on time that can be measured in this mode is 20 years. The on-time value is kept in RAM. The value is copied to non-volatile EEPROM

once per day just past midnight as determined by the node object, whenever the node is sent offline, and whenever the functional block is commanded to go to the disabled state. Power cycles or watchdog timeouts will lose the RAM on-time values. After recovery from any of these events the last count stored in EEPROM will be loaded into the RAM counter

If the hardware input has been configured for Dry Contact the input may be configured to be debounced with a configurable time period. If the hardware input has been configured for voltage input (5V, 12V, 24V, or 31V) debounce is not supported

The LonPoint Application and Plug-in Guide 3-7

Frequency

Measures the frequency of the input signal in the range of 1Hz to 20kHz. Minimum resolution of the frequency measurement is <0.5% over the full measurement range. The Analog network variable reports the instantaneous measured frequency or a translated representation of it. The Digital network variable is not used with this processing option.

On startup the Analog output network variable is not immediately available as the input is auto-ranged. This process takes up to four seconds.

The frequency measurement may be modified using a translation table. The translation table operates in the same manner as the translation table in the Analog input functional block found in the AI-10 LonPoint Module. The translation table is in turn followed by a filtering function. The filter averages over N samples, where N is the configured filter length. The supported range of N is 1 to 255. The equivalent filter time constant for this range is approximately

0.5 seconds to 50 seconds. No filtering is done if N equals 1. If no translation is applied, an appropriate network variable type for the Analog

output network variable in this mode is then the appropriate floating point SNVT for the process variable being measured should be used (e.g.

The input cannot be configured for dry contact when the frequency processing option is selected. Debounce is not supported. The hardware input may be configured for voltage input (5V, 12V, 24V, or 31V only).

SNVT_flow_f).

SNVT_freq_f. If translation is applied

Using The Control Network Variable

The Control network variable can be driven from another device on the network or an HMI application. It is sequenced in a way that allows count values to be sampled while continuing to count without interruption. It applies to the Count, Repeating Count, and On Time processing options. The variable type is

The following summarizes the input values to the

RUN Enables event counting. The count value is output to

CLEAR Copies the internal count to the Analog network

UNVT_count_control.

Analog network variable. The send-on-delta value

the is used to throttle the network variable, so the network variable is not necessarily propagated with every count.

variable and then clears the internal count. Events continue to be counted, but the variable is not updated. This allows an HMI application to read the while the The HMI application can set the variable to variable.

Control network variable is set to CLEAR.

RUN after reading the Analog network

Control network

Control network variable:

Analog network

Analog network variable

Control network

3-8 Digital Input/Counter Functional Block

HOLD Holds the current value of the Analog network

PAUSE Disables event counting. The internal count value

PRESET Presets the counter to the value specified in the preset

Processing Parameters

This tab appears as follows:

variable. Events are accumulated but the network variable is not updated. The to the Repeating Count processing option. The Analog network variable will continue to update if Repeating Count is selected.

and Analog network variable are not updated.

value configuration property. The new value updates the stored count in EEPROM.

HOLD state does not apply

This tab allows you to set several parameters relating to the processing option selected in the Digital Input/Counter tab. The following parameters may be set using this tab:

Count Repeat Value This parameter is only used if the processing option is

Repeating Count. This integer value

set to determines the terminal count used for this processing option (e.g. a value of 5 would result in a count of 0, 1, 2, 3, 4, 0, 1, 2, …).

The LonPoint Application and Plug-in Guide 3-9

Frequency Filter Length This parameter is only used if the processing option is

Default Control Value This parameter is only used if the processing option is

Translation

This tab appears as follows:

Frequency. This value may be set from 1 to

set to 255 and determines the number of readings that are sampled and averaged before a value is passed to the Analog network variable.

Count, Repeating Count, or On Time. This

set to value determines the control value if the Control input network variable is not connected or has not received an update since the devices last reset.

This tab is only used if the Frequency processing option is selected and the

Translation option is selected in the Digital Input/Counter tab.

This tab allows you to set up a translation table which translates the raw measured data into the values to be sent by the after filtering (see the

The translation table provides a means for mapping any input set of values into a different set of output values via pairs of input/output values. The Digital

Frequency processing option, earlier in this chapter).

Analog output network variable

3-10 Digital Input/Counter Functional Block

Input/Counter software automatically linearly interpolates to determine translation values that lie between defined input/output pairs.

The table must contain at least two input/output pairs and may contain as many as twenty.

The only constraint on the Measured Value column is that the entries increase in value. To mark the end of the table, enter a measured value less than the preceding one.

Click the Save button to save translation table data into a tab-delimited text file. Click the Load button to load data from a tab-delimited text file into a translation table. Use these functions to save and reuse commonly used translation tables for your hardware inputs. You can also use custom LonMaker shapes to save frequently used configurations.

Output Parameters

This tab appears as follows:

This tab allows you to determine parameters for the output network variables on the Digital Input/Counter functional block. Not all of the parameters are configurable for every processing option.

Offset This parameter is only used if the

processing option is being used. This value is added to the sensed reading prior to sending the reading on

The LonPoint Application and Plug-in Guide 3-11

Frequency

the Analog network variable. The offset may be positive or negative. The units match the units being sent on the Analog network variable. The offset is applied after the translation.

Minimum Value This parameter is only used if the

processing option is being used. This value determines the minimum value that will be sent by the Analog network variable. If this limit is exceeded the output will be clipped at this limit.

Maximum Value This parameter is only used if the

processing option is being used. This value determines the maximum value that will be sent by the Analog network variable. If this limit is exceeded the output will be clipped at this limit.

Send on Delta This parameter is only used if the

Count, On Time, or Frequency processing option is

being used. The sensed value must change by at least this amount before a new value is sent. A new value will still be sent if the heartbeat time expires.

Analog Override This parameter is only used if the

Count, On Time, or Frequency processing option is

being used. This value determines the value that will be sent by the Analog network variable if this functional block is put into override.

Digital Override This parameter is only used if any processing option

other than determines the value that will be sent by the Digital network variable if this functional block is put into override.

Frequency is being used. This value

Frequency

Count, Repeating

Heartbeat Determines how often the functional block sends a

heartbeat over the network over each of its output network variables. The behavior of the system in case of a missed heartbeat is determined by the functional blocks which fail to receive the heartbeat. Setting this property to 0 disables the heartbeat for this functional block. Disabling the heartbeat causes the output network variable to only be transmitted in response to a changed hardware input value.

Throttle Limits how often data is sent over the network.

Setting this property to 0 disables throttling.

Status

This tab allows you to view and change the status of a Digital Input/Counter functional block. See Status in Chapter 2 for more information.

3-12 Digital Input/Counter Functional Block

The Digital Output Functional

Block: Application and Plug-in

This chapter describes how to configure a Digital Output functional block using the LonPoint Plug-in.

The LonPoint Application and Plug-in Guide 4-1

The Digital Output Functional Block

The Digital Output functional block controls the state of a digital actuator based on the value of an input network variable. The following figure and tables summarize the inputs and outputs of the Digital Output functional block:

Input Network Variables

Default name Default type Description

Digital SNVT_switch The Digital input network variable

that drives the actuator.

Mode SNVT_hvac_mode

(changeable)

Enable SNVT_switch The Enable input network variable.

Output Network Variables

Default name Default type Description

Feedback SNVT_switch The output value controlling the

The Mode input network variable. See the Presets tab for more information.

If this network variable is set to On, the functional block will function normally. If this network variable is set to Off, the actuator driven by this functional block will return to its default state.

actuator driven by this functional block.

Configuring a Digital Output with the LonPoint Plug-in

Right-click a Digital Output functional block and select Configure from the shortcut menu to open the LonPoint Plug-in. The Digital Output window of the LonPoint Plug-in contains the following tabs:

Defaults, Presets, Output Parameters, Heartbeats, and Status.

Digital Output, Input

4-2 Digital Output Functional Block

Digital Output

This tab appears as follows:

This tab displays the flow of information through the Digital Output functional block. It contains the following fields:

Location The location string for this digital output. This

property can be used to document the associated actuator’s location within the plant so it can be easily found. This field may contain up to 30 characters. This value is separate from the LonPoint device’s location property.

Digital Input Invert Specifies whether or not the value of the

network variable is inverted before it is processed.

Enable Invert Specifies whether or not the value of the

network variable is inverted before it is processed. If not selected, an On value enables the output.

Output Invert Specifies whether or not the value of the digital

output value is inverted before it is sent to the attached hardware. This option does not apply to the

Feedback output.

Digital

Enable

The LonPoint Application and Plug-in Guide 4-3

Debounce Determines how long the Digital input network

variable and the remain stable after a transition in order for the transition to be recognized as valid. This prevents the state from fluttering. This configuration property may be set between 0 and 999 ms. A value of 0 turns the debounce function off.

Processing Determines how the debounced input data is

translated into the value used to drive the actuator. This configuration property can be set to one of the following options:

Pulsed, or One-Shot. The Delayed, Pulsed and One-Shot options use the time fields below. If the Delayed option is selected, these fields will be

labeled the fields will be labeled

Time.

The after the debounce function has been executed.

The to be delayed by the time indicated in the

Time field and a change from On to off to be delayed

by the time indicated in the

On Delay Time and Off Delay Time. If

Pulsed or One-Shot option is selected, these

Direct option causes data to be output directly

Delayed option causes a change from Off to On

Mode input network variable must

Direct, Delayed, Toggled,

On Delay Time and Pulse

On Delay

Off Delay Time field.

Toggled option causes the output data to toggle

The every time the input data changes from Off to On.

Use the output network variable every time the input data changes from Off to On. The pulse is generated after a delay specified on the duration of the pulse is specified on the field. It does not matter how long the input data remains on, the output will always send a pulse of the specified length after waiting the configured delay.

Use the output network variable every time the input data changes from Off to On. The pulse is generated after a delay specified on the duration of the pulse is specified on the field. If the input data is changed from Off to On while the pulse is being sent, the pulse timer will be reset (i.e., if a two second pulse was retriggered after one second, the output would be on for two more seconds, or three seconds total). If a delayed pulse is re-triggered during a pulse, the delay will be ignored. If a pulse is re-triggered during a delay, the trigger will be ignored.

Pulsed option to generate a pulse on the

On Delay Time field. The

Pulse Time

One-Shot option to generate a pulse on the

On Delay Time field. The

Pulse Time

On Delay Time Use this field with the

Shot processing options. This value determines the

Delayed, Pulsed, and One-

4-4 Digital Output Functional Block

length of the delay in the change from the Off state to the On state. To change the value, click the button to the right of the time value to be changed and enter the new values to be used for the delay. The valid range for this value is from zero to 48 days, 23 hours, 59 minutes, and 999 milliseconds.

Off Delay Time Use this field with the

This value determines the length of the delay in the change from the On state to the Off state. To change the value, click the button to the right of the time value to be changed and enter the new millisecond, second, and minute values to be used for the delay. The valid range for this value is from zero to 48 days, 23 hours, 59 minutes, 59 seconds, and 999 milliseconds.

Pulse Time If you select either the

options, the Pulse Time field appears in place of Off

Delay Time. This value determines the length of

time the On state remains active. To change the value, click the button to the right of the time value to be changed and enter the new millisecond, second, and minute values to be used for the delay. The valid range for this value is from zero to 48 days, 23 hours, 59 minutes, 59 seconds, and 999 milliseconds.

Delayed Processing option.

Pulsed or the One-Shot

The LonPoint Application and Plug-in Guide 4-5

Input Defaults

This tab appears as follows:

This tab allows you to set the default inputs for the Digital Value, Mode, and

Enable input network variables. The specified input values will be used if the

associated network variable is not connected or has not received an update since the device’s last reset.

4-6 Digital Output Functional Block

Presets

This tab appears as follows:

This tab allows you to set up the preset table which determines how the digital output behaves for each mode value. For each value that the variable can receive, you can configure whether the output value will be taken from the selected mode. Select value. Select

Digital network variable or will be set to a preset value for the

Use Network Variable to use the network variable

Use Preset Value to use the specified preset value.

Mode network

The LonPoint Application and Plug-in Guide 4-7

Output Parameters

This tab appears as follows:

This tab allows you to set options determining what information is sent to the output. This tab contains the following fields:

Default Value Determines the value that will be sent to the hardware if

the block is disabled or has detected a heartbeat failure.

Override Value Indicates the output value that will be used if the

functional block is put into override. This value will be inverted if the Output Invert option is selected.

Min On/Min Off Indicates the minimum amount of time an On to Off

condition will be sent to the hardware digital output and

Feedback network variable. If the Pulsed or One-

the shot processing option is being used, there will always be a delay of at least the Min Off time between pulses. To modify the value in either of these fields, click the associated button and enter appropriate values in the

Day, Hour, Minute, Second, and Millisecond fields.

4-8 Digital Output Functional Block

Heartbeats

This tab appears as follows:

This tab allows you to set properties that determine the input and output heartbeat rates and feedback sampling. This tab contains the following fields:

Input Heartbeat This property determines the interval (in seconds) the

network variables that have the Use Heartbeat option selected will wait for a heartbeat before detecting a heartbeat failure. See Heartbeats, in Chapter 1, for more information.

Use Heartbeat Specifies whether or not heartbeat checking will be

used for the selected input network variable. If checked for a given network variable, it indicates that heartbeat checking will be used. The maximum time between updates for network variables with heartbeat checking enabled is set in the

Heartbeat field. Click the ALL or None button to

turn heartbeat checking On or Off for all input network variables, respectively.

Output Heartbeat Determines the heartbeat send rate, in seconds, for

Feedback output network variable.

the

Feedback Sample Determines how often the hardware digital output is

sampled for the purpose of updating the

Input

Feedback

The LonPoint Application and Plug-in Guide 4-9

Status

output network variable. This signal can come from a network variable or from the The signal being sent to the hardware digital output is sampled at this rate, and the network variable is updated whenever the value changes or when determined by the heartbeat.

This tab allows you to view and change the status of the Digital Output functional block. See Status in Chapter 2 for more information.

Hand-Off-Auto switch.

4-10 Digital Output Functional Block

The Digital Encoder Functional

Block: Application and Plug-in

This chapter describes how to configure a Digital Encoder functional block using the LonPoint Plug-in.

The LonPoint Application and Plug-in Guide 5-1

The Digital Encoder Functional Block

The Digital Encoder functional block performs logic functions on four digital input network variables to create a digital output network variable and a mode output network variable. The following figure and tables summarize the inputs and outputs of the Digital Encoder functional block:

Input Network Variables

Default name Default type Description

D1/D2/D3/D4

Default name Default type Description

Digital_Out

Mode_Out

SNVT_switch

Output Network Variables

SNVT_switch

SNVT_hvac_mode

(changeable)

Four digital input network variables which are processed by the Digital Encoder.

The digital output network variable determined by the Digital Encoder.

The mode output network variable determined by the Digital Encoder.

Configuring the Digital Encoder with the LonPoint Plug-in

Right-click a Digital Encoder functional block and select Configure from the shortcut menu to open the LonPoint Plug-in. The Digital Encoder window of the LonPoint Plug-in contains the following tabs:

Tables, Heartbeats, and Status.

Digital Encoder, Lookup

5-2 Digital Encoder Functional Block

Digital Encoder

This tab appears as follows:

This tab displays the flow of data through the Digital Encoder functional block. This tab contains the following fields:

Delay Specifies the amount of time the digital inputs must

stay constant before they are processed. The value must be between zero and 48 days, 23 hours, 59 minutes, 59 seconds, and 999 milliseconds. To change the value, click the button to the right of the time value to be changed and enter the new values to be used for the delay. Set this field to zero to disable the delay function.

Digital Output Override Selects the value that will be sent on the

Digital_Out network variable when the functional

block is put into override.

Mode Output Override Selects the value that will be sent on the

network variable when the functional block is put into override.

Mode_Out

The LonPoint Application and Plug-in Guide 5-3

Lookup Tables

This tab appears as follows:

This tab contains the lookup table that determines the output of the

Digital_Out and Mode_Out network variables based on the values of the 4

digital inputs. Each row of the table corresponds to one of the 16 possible combinations of input values from the four digital inputs.

For each combination of inputs, you can set an output value for the

Digital_Out network variable in the Digital Output column and the Mode_Out network variable in the Mode Output column. The fields in the Digital Output column can be set to 0 to send an Off digital state, 200 to send

an On digital state, or a value between 0 and 200 to send an On value with a level less than 100% (the level is one half the specified value).

The available values in the

Mode_Out network variable selected on the Digital Encoder tab.

Mode Output column depend on the type of the

5-4 Digital Encoder Functional Block

For example, to create a digital encoder block that returns an On value on the Digital Output when the D3 AND D4 inputs are on and on Off value otherwise, enter a value of 0 in the either or both of the D3 and D4 inputs are 0) and a value of 200 in the

Output column in the remaining rows (in which both D3 and D4 have a value of

1), as follows:

Digital Output column in the first 12 rows (in which

Digital

The LonPoint Application and Plug-in Guide 5-5

To create a table that sends an HVAC_EMERG_HEAT mode on the Mode_Out network variable if any of the four inputs are On and HVAC_AUTO if they are all Off, you would set the the rows but the first (in which at least one of the four inputs has a value of 1) and to HVAC_AUTO in the first row (where all four inputs are 0), as follows:

Mode Output column to HVAC_EMERG_HEAT in all

5-6 Digital Encoder Functional Block

Heartbeats

This tab appears as follows:

This tab allows you to set heartbeat and throttle options for the input and output network variables on the Digital Encoder functional block. This tab contains the following fields:

Input Heartbeat Determines the interval (in seconds) the network

variables that have the selected will wait for a heartbeat before registering a heartbeat failure. See Heartbeats in Chapter 1 for more information

Use Heartbeat Determines whether heartbeat checking will be used

for each of the four input network variables. The and None buttons allow you to enable heartbeat checking for all input network variables or none of the input network variables, respectively.

Output Heartbeat Determines the output heartbeat, in seconds, for both

output network variables. This is the maximum amount of time that may pass without a network variable update before one is sent automatically. Set

Use Heartbeat option

All

The LonPoint Application and Plug-in Guide 5-7

Status

this field to zero to disable heartbeats for both output network variables.

Throttle Determines the throttle, in milliseconds, for both

output network variables. This is the minimum amount of time between two network variable updates. Set this field to zero to disable throttling for both output network variables.

This tab allows you to view and change the status of a Digital Encoder functional block. See Status in Chapter 2 for more information.

5-8 Digital Encoder Functional Block

The Analog Input Functional

Block: Application and Plug-in

This chapter describes how to configure an Analog Input functional block using the LonPoint Plug-in.

The LonPoint Application and Plug-in Guide 6-1

The Analog Input Functional Block

The Analog Input functional block measures the voltage, current, or resistance of a hardware transducer. This value is then translated into an appropriate value to send on the temperature transducer might return a value of 10,000 to 15,000 ohms. The Analog Input functional block translates this raw value into the appropriate temperature value using a translation table. The following figure and table summarizes the output of the Analog Input functional block:

Default name Default type Description

Analog output network variable. For example, a

Output Network Variables

Analog SNVT_temp_f

(changeable)

The Analog output network variable driven by the sensor.

Configuring an Analog Input with the LonPoint Plug-in

Right-click an Analog Input functional block and select Configure from the shortcut menu to open the LonPoint Plug-in. The Analog Input window of the LonPoint Plug-in contains the following tabs:

Output Parameters, and Status.

Analog Input, Translation,

6-2 Analog Input Functional Block

Analog Input

This tab appears as follows:

This tab shows the flow of information through the Analog Input functional block. It contains the following fields:

Measurement Type Determines whether the input reads voltage (Volts),

current (Amps), or resistance (Ohms). The value in this field must match the hardware settings on the associated LonPoint module. See the LonPoint Hardware and Installation Guide for information on changing the hardware settings.

Measurement Current If the Measurement Type field is set to Ohms, this

field determines whether a current of 25

µA is used in measuring resistance. If the

Measurement Type field is set to Volts or Amps, this field is not used.

Input Gain Determines the gain for the input. See Analog Input

Gain and Current Settings later in this chapter for

more information on gain settings.

Measurement Limit Displays a calculation of the highest value that may

be read from the transducer, as determined by the

µA or 400

The LonPoint Application and Plug-in Guide 6-3

Measurement Type, Measurement Current, and Input Gain values.

Filter Sets the input noise filtering on the device to reject

either 50 Hz or 60 Hz noise.

Translation Enabled Determines whether the translation table, set up in

Translation tab, will be used. If this option is

the disabled, the untranslated, or raw, values will be used as read from the transducer.

Device Offset The value set in this field is added to the sensed

reading to account for device-to-device transducer variations. The units match the units being sent on the network variable. This offset is applied after the translation.

For example, if a 100 ice-point, the offset should be –0.12.

Sample Interval Controls the rate that the analog input samples the

input hardware and updates its output network variable. This field may be set to 500 ms, 1 sec, 2 sec, 4 sec, 8 sec, 16 sec, or 32 sec.

Location The location string for this analog input. This

property can be used to document the associated input’s location within the plant so it can be easily found. This field may contain up to 30 characters. This value is separate from the device’s location string.

Ω RTD measures 0.12º C at the

6-4 Analog Input Functional Block

Translation

This tab appears as follows:

This tab allows you to set up a translation table that translates the raw measured data into the values to be sent over the variable.

The translation table provides a means for mapping any input set of values into a different set of output values via pairs of input/output values. The Analog Input software automatically linearly interpolates to determine translation values that lie between defined input/output pairs.

The table must contain at least two input/output pairs and may contain as many as twenty.

The only constraint on the Measured Value column is that the entries increase monotonically (i.e. each value in the column must be greater than the previous value). To mark the end of the table, enter a measured value less than the preceding value.

Analog output network

The LonPoint Application and Plug-in Guide 6-5

All fields on this tab will be disabled if the Translation Enabled option is not set on the

Analog Input tab.

Output Parameters

This tab appears as follows:

This tab determines how often data is sent on the Analog network variable and the minimum, maximum, and override values. This tab contains the following fields:

Minimum Value The minimum value that will be sent by the output

network variable. If this limit is exceeded the output will be clipped at this limit.

Maximum Value The maximum value that will be sent by the output

network variable. If this limit is exceeded the output will be clipped at this limit.

Send on Delta The sensed value must change by at least this

amount before a new value is sent. A new value will still be sent if the heartbeat time expires.

Override The value that will be sent by the

network variable if this functional block is put into override.

Analog output

6-6 Analog Input Functional Block

Heartbeat Determines how often the functional block sends a

heartbeat over the network. The behavior of the system in case of a failed heartbeat is determined by the functional blocks which fail to receive the heartbeat. Setting this property to 0 disables the heartbeat for this functional block. Disabling the heartbeat causes the output network variable to only be transmitted in response to a changed hardware input value.

Status

This tab allows you to view and change the status of an Analog Input functional block. See Status in Chapter 2 for more information.

Analog Input Gain and Current Settings

The analog-to-digital (A/D) converters on the LonPoint module must be properly configured to match the plug-in. These can be set via hardware jumpers as described in the LonPoint Hardware and Installation Guide.

ADC Settings set in the Analog Input tab of the

The A/D converters on the module can be programmed for four different input gains: 1, 2, 32, and 128. The gain settings affect the Ohms, Volts, and Amps mode settings in different ways, and each will be discussed separately. In addition, the measurement current for the Ohms setting can be set to one of two different values.

Amps Measurement Type (2WIR and 4WIR Jumper Settings)

As a rule, the A/D gain should be set to the maximum allowable level so as not to create an overflow condition. This allows the maximum possible resolution. Based on the gain setting, the software converts each raw number reading to the correct value. For current measurement settings (the 2WIR and 4WIR modes), the gain should be set to 1 for any standard 4-20mA current loop. For example, a gain of 2 would reduce the maximum allowable current to 12.5mA, which would not be useful for a 4-20mA current loop.

There are no other software settings associated with the 2WIR or 4WIR settings.

Ohms Measurement Type (RES Jumper Setting)

The resistance measurement setting configures the LonPoint module to measure the voltage drop from a constant current source through the resistor to be measured.

There are two resistance measuring current settings: 25µA and 400µA. The 25µA setting is typically used for thermistors, while the 400µA setting is typically used for RTDs. The determination whether to use the 25µA or 400µA

The LonPoint Application and Plug-in Guide 6-7

current setting is determined by two factors: absolute range and self-heating

Range @ 400µA

/step @ 400µA

limitations. The absolute range refers to the upper input voltage limit of the A/D converter

after voltage input scaling: 2.500VDC (scaling allows measurement of voltages higher than this limit). Any voltage higher than this limit will not be measurable. The maximum resistance that can be measured at 25µA is

2.5V/25e-6A = 100k higher than 100k module but they will not be measurable.

Self-heating is another consideration that may merit the use of the lower 25µA current setting, even if the absolute limit is not a factor. Heat is generated whenever a current is passed through a resistor, but when you’re trying to measure temperature this heat generation affects the accuracy of the reading. How much the accuracy is affected depends on the current, the thermal mass of the input, airflow, and so on.

The amount of self-heating power can be calculated by squaring the current and multiplying by the resistance. For example, a 2k

1.25µW of dissipation at the 25µA setting (25µA x 25µA x 2000 self-heating energy dissipation at the 400µA current setting (400µA x 400µA x

Ω). The error resulting from heat-dissipation depends on the dissipation

2000 constant of the sensor. For example, Kele PreCon thermistors have a dissipation constant of 2.7mW/°C in still air at room temperature. To calculate the measurement error, the power dissipation is divided by the dissipation constant, as follows:

Ω, and at 400µA is 2.5V/400e-6A = 6.25kΩ. Resistances

Ω at 25µA, or 6.25kΩ at 400µA, will not damage the LonPoint

Ω thermistor would have

Ω), and 320µW of

Current Measurement Error

25µA 1.25µAW/2700µW/dC = 0.0005°C (0.0008°F) 400µA 320µAW/2700µW/dC = 0.12°C (0.22°F)

Depending on the system, these self-heating errors may be small or large compared to the accuracy of most thermistors; however, they should be taken into consideration when selecting a current setting.

RTDs have a larger thermal mass, larger dissipation area, and low initial resistance, and are therefore not as susceptible as thermistors to significant selfheating errors.

Once the measurement current has been set, the gain should be adjusted to the maximum value that doesn’t generate over-range errors. The resistor ranges for the various settings are shown in this table:

AI-10 Analog Input Module RES Settings

Gain Setting

x1 x2

x32

x128

0 - 6.25k 0 - 3.12k

0 - 195

0 - 49

Ω Ω Ω

Ω

0.0953

0.0477

0.00298

0.000745

Range @ 25µA Ω/step @ 25µA

0 - 88k 0 - 50k

0 - 3.12k

0 - 781

Ω Ω

Ω

1.525

0.763

0.048

0.0119

6-8 Analog Input Functional Block

Volts Measurement Type (VOLT Jumper Setting)

Voltage measurement involves applying voltage across the Base Plate input terminals (10-11 or 12-13), making sure to note the correct polarity, setting the gain accordingly, and then reading the voltage. The input resistance of the AI10 in voltage mode is 7,246 drive that load in order to obtain consistent results.

Based on the gain setting, the input ranges available are shown in the following table:

AI-10 Analog Input Module Gain Setting and Voltage Range

Gain Setting Voltage Range

Ω ± 0.3%, and the attached sensor must be able to

x1 0 - 20V x2 0 - 10V

x32 0 - 625mV

x128 0 - 156mV

The LonPoint Application and Plug-in Guide 6-9

6-10 Analog Input Functional Block

The Analog Output Functional

Block: Application and Plug-in

This chapter describes how to configure an Analog Output functional block using the LonPoint Plug-in.

The LonPoint Application and Plug-in Guide 7-1

The Analog Output Functional Block

The Analog Output functional block translates an input network variable value to a value that is used to drive a hardware output. The functional block may be configured to translate the value into voltage or current, depending on the requirements of the hardware output being driven. The following figure and tables summarize the inputs and outputs of the Analog Output functional block:

Input Network Variables

Default name Default type Description

Analog SNVT_lev_cont_f The Analog input network variable

that drives the actuator.

Mode SNVT_hvac_mode

(changeable)

Enable SNVT_switch The Enable input network variable.

Output Network Variables

Default name Default type Description

Feedback SNVT_lev_cont_f The sensed output of the actuator

Configuring an Analog Output

Right-clicking on an Analog Output functional block and select Configure from the shortcut menu to open the LonPoint Plug-in. The Analog Output window of the LonPoint Plug-in opens. This window contains the following tabs:

Output, Defaults, Presets, Heartbeats, and Status.

The Mode input network variable. See the Presets tab for more information.

If this network variable is set to On, the functional block will function normally. If this network variable is set to Off, the output to the actuator driven by this functional block will return to its default state.

driven by this functional block.

Analog

7-2 Analog Output Functional Block

Analog Output

This tab appears as follows:

This tab sets configuration properties that determine how the values received by the input network variables are processed by the functional block and what values are sent to the physical actuator. This tab allows you to set the following fields:

Location The location string for this analog output. This

property can be used to document the associated actuator’s location within the plant so it can be easily found. This field may contain up to 30 characters. This value is not the device’s location property.

Invert Inverts the value received on the

variable. If this option is selected, sending an Off value to the input.

Input Range Defines the minimum and maximum input values

that correspond to the minimum and maximum output values. If the input falls below the minimum, the output is set to the minimum output value. If the input exceeds that maximum, the output is set to the maximum output value. If the

Enable network variable will enable the

Enable network

Enabled option is not

The LonPoint Application and Plug-in Guide 7-3

Defaults

selected, the input range is 0 to 100%. Input ranging is useful for split-range applications where a single value drives multiple actuators, but each actuator is active over a different input range.

The analog output functional block can be configured to be reversing (i.e. go from 0% to 100% as the input goes from 100% to 0%) by switching either the Input Range or the Output Range values.

Output Range Defines the minimum and maximum range of the

output. The Output Type field determines whether a current or voltage will be sent to the actuator. These units must match the hardware jumpers set in the device (see the LonPoint Module Hardware and Installation Guide).

This tab appears as follows:

This tab sets the default and override values for the analog output functional block. This tab contains the following fields:

Analog Value Default This value will be used if the

variable is not connected or has not received an update since the last device reset.

Analog network

7-4 Analog Output Functional Block

Mode Default This value will be used if the Mode network variable

is not connected or has not received an update since the last device reset.

Presets

Enable Default This value will be used if the

variable is not connected or has not received an update since the last device reset.

Output Default This value will be sent to the physical actuator if the

functional block is disabled or has detected a heartbeat failure.

Override This value will be sent to the hardware output if the

functional block is put into override.

This tab appears as follows:

Enable network

This tab allows you to set up the preset table that determines how the Analog output behaves for each mode value. Each value in the View Mode list corresponds to a mode value. For each value that may be received by the network variable, you can specify whether the output value to the actuator will be taken from the

Use Network Variable to use the network variable value for the selected

mode. Select

Analog input network variable or set to a preset value. Select

Use Preset Value to use the specified preset value.

Mode

The LonPoint Application and Plug-in Guide 7-5

Heartbeats

This tab appears as follows:

Status

This tab allows you to configure the input heartbeat rates. This tab contains the following fields:

Input Heartbeat Determines the interval (in seconds) the network

variables that have the selected will wait for a heartbeat before registering a heartbeat failure.

Use Heartbeat Specifies whether or not heartbeat checking will be

used for the selected input network variables. Click the All or None buttons to turn heartbeats on or off for all network variables.

Output Heartbeat Determines the heartbeat send time in seconds for

Feedback network variable. A value of 0

the disables the output heartbeat.

This tab allows you to view and change the status of an Analog Output functional block. See Status in Chapter 2 for more information.

Use Heartbeat option

7-6 Analog Output Functional Block

The AFB Functional Block:

Application and Plug-in

This chapter describes how to configure an Analog Function Block (AFB) functional block using the LonPoint Plug-in.

The LonPoint Application and Plug-in Guide 8-1

The Analog Function Block (AFB) Functional Block

The AFB functional block performs mathematical, logical, or enthalpy functions using up to 2 analog inputs and a digital input (not all inputs are used for all functions). The following figure and tables summarize the inputs and outputs of the AFB functional block:

Input Network Variables

Default name Default type Description

A1/A2

Digital

Default name Default type Description

A_Out

Digital_Out

SNVT_temp_f

(changeable)

SNVT_switch

Output Network Variables

SNVT_temp_f

(changeable)

SNVT_switch

Two Analog input network variables that are processed by the AFB functional block.

A Digital input network variable that is processed by the AFB functional block.

An Analog output network variable set by the AFB functional block.

A Digital output network variable set by the AFB functional block.

Configuring the AFB Functional Block using the LonPoint Plug-in

Right-click an AFB functional block shape and select Configure from the shortcut menu to open the AFB window of the LonPoint Plug-in. The AFB window contains six tabs:

Outputs, Heartbeats, and Status.

Analog Function Block, Inputs, Function,

8-2 Analog Function Block Functional Block

Analog Function Block

This tab appears as follows:

This tab displays the flow of information through the AFB functional block. For each of the analog inputs, use the

A2 network variable value or a constant value will be used. Use the Function

tab to specify the function to be performed on the two values.

Inputs tab to determine whether the A1 or

The LonPoint Application and Plug-in Guide 8-3

Inputs

This tab appears as follows:

This tab determines what values are used for the analog operands. For each of the two operands, you can use the associated network variable by selecting

Network Variable, or use a constant by selecting Use Constant and setting

the corresponding field to the desired constant value. The constant type depends on the input network variable type specified on the Analog Function Block tab. Select the be passed to the calculation. You can use the choose the None of the values or options on this tab can be changed if the is selected on the

The only enabled if the corresponding analog input network variable is using the

SNVT_temp_f network variable type with the Fahrenheit format

SNVT_temp#US). If Absolute is set, the network variable or constant input will

( be interpreted as a point on the temperature scale (i.e. 32 degrees Fahrenheit would be interpreted as 0 degrees Celsius). If variable or constant will be treated as a difference between two temperatures (i.e. 0 degrees Fahrenheit would be interpreted as 0 degrees Celsius). If the

Square Root option to have the square root of the associated value

Square Root option only if you

Use Network Variable option and you select a math function.

Enthalpy mode

Function tab.

Absolute and Differential options apply to the constant values and are

Differential is set, the network

Use

8-4 Analog Function Block Functional Block

Analog Input network variable is formatted as SNVT_temp_f#US_diff, this option is disabled and

Differential is automatically selected.

This option can only be modified by the user if you are using a (see the Function tab). All temperatures are internally represented in degrees Celsius and all calculations are performed in Celsius, therefore, if you are using Fahrenheit values, you must indicate whether the Fahrenheit temperature from each input is to be interpreted as an actual temperature or a differential. For example, if you were comparing a Fahrenheit temperature input to a setpoint constant to determine which one was greater, select the you were comparing the difference between two Fahrenheit temperatures (as calculated by another AFB functional block) to a constant to determine whether the difference between them was larger than the constant, select the

Differential setting.

If the Add or Subtract is automatically set to chosen, this option is automatically set to (input constants will be treated as unitless). Multiplying temperatures displayed as Fahrenheit may yield unexpected results, since calculations are performed in Celsius and

Note:

The you start the plug-in, the default setting is entered a constant value using the reselect this setting each time you start the plug-in for the value to be interpreted correctly.

32 * 2 is not equivalent to 0 * 2.

Absolute/Differential setting is not saved by the plug-in. When

Math function is chosen (see the Function tab), this option

Differential. If the Multiply or Divide Math function is

Absolute for input network variables

Absolute. If you previously

Differential setting, you need to

Absolute setting. If

Logic function

The LonPoint Application and Plug-in Guide 8-5

Function

This tab appears as follows:

Function Type Determines whether the analog function block

performs a

Logic Function options determine what operation will be used if the

The function type is set to

High Select The higher of the two analog operands will be sent to

Low Select The lower of the two analog operands will be sent to

Relay The digital input will select which of the two analog

Greater Than The

Logic. The following options are available:

the analog output.

operands is sent to the analog output. If the digital input is Off, the Operand 1 value is sent to

Output. If the digital input is On, the Operand 2

value is sent to

Digital_Out network variable will be set to On

if the value from Operand 1 is greater than the value from Operand 2. Otherwise, an Off value will be sent. Changes to the output value are affected by the

Hysteresis value (see below).

Logic, Math, or Enthalpy function.

Analog

Analog Output.

8-6 Analog Function Block Functional Block

Less Than The Digital_Out network variable will be set to On

if the value from Operand 1 is less than the value from Operand 2. Otherwise, an Off value will be sent. Changes to the output value are affected by the

Hysteresis value (see below).

Greater Than or Equal The

Less Than or Equal The

Math Function options determine what operation is to be performed if the

The

Math function type was selected in the Function Type field. The available

options are is always

The Hysteresis field determines how great a difference, as a floating point number, must exist between the analog values for the

Than, Greater Than or Equal, and Less Than or Equal logic functions to

change the digital output. You can use this field only if the mode is set to one of these comparison logic operations.

Selecting the temperature and humidity.

Operand 2 must be a SNVT_lev_cont_f type. There is no SNVT defined for

enthalpy that can be used for the Echelon user type file (ECHELON.TYP) provides a that you can use for this purpose.

Add, Subtract, Multiply, and Divide. The order of the equation

Operand 1 [plus\minus\times\divided by] Operand 2.

Enthalpy function calculates the heat content of air, based on the

Digital_Out network variable will be set to On

if the value from Operand 1 is greater than or equal to the value from Operand 2. Otherwise, an Off value will be sent. Changes to the output value are affected by the

Digital_Out network variable will be set to On

if the value from Operand 1 is less than or equal to the value from Operand 2. Otherwise, an Off value will be sent. Changes to the output value are affected by the

Hysteresis value (see below).

Operand 1 must be a SNVT_temp_f type, and

Analog Output network variable, but the

Hysteresis value (see below).

Greater Than, Less

UNVT_enthalpy user type

The LonPoint Application and Plug-in Guide 8-7

Outputs

This tab appears as follows:

This tab determines what value is sent to the A_Out and Digital_Out network variables based on the output from the Math, Logic, or Enthalpy function performed by the Analog Function Block.

Delay Specifies a time that the result of the calculation

made by the AFB must remain constant to be sent on the appropriate output network variable. The value can be up to 48 days, 23 hours, 59 minutes, 59 seconds, and 999 milliseconds. To change the value, click the button to the right of the time value to be changed and enter the new values to be used for the delay.

Scaling Set up scaling for analog values. The

represents the value derived from the AFB function, and the will be sent on the side, a of the function moves from the on the left, the value sent to the network moves from the done linearly.

Output column represents the value that

A_Out network variable. For each

High and Low value must be set. As the result

Low to the High value

Low to the High value on the right. The scaling is

Input column

8-8 Analog Function Block Functional Block

The type of the values in the Output column depend on the selected on the

Analog Output network variable type you

Analog Function Block tab.

The type of the values in the always be determined. For functions the units are normally displayed. All other cases show units as shown are in (or derived from) the native units of the input network variables (normally SI units). Caution should be used when scaling Fahrenheit temperatures. You can temporarily change the format of the input network variables to SI units to verify your values.

Scaling can be set up to be Reverse Acting (i.e. the output decreases as the input increases) by setting

High value lower than the Low value for either

the

Input or the Output column (but not both).

the Scaling is applicable to all analog output function

types except

Override This field exists for both the

Digital_Out network variables. This value will be

sent on the corresponding output network variable when the AFB functional block is put into override.

Enthalpy.

? (Native) and the values

Input column cannot

Add and Subtract

A_Out and

The LonPoint Application and Plug-in Guide 8-9

Heartbeats

This tab appears as follows:

This tab determines the heartbeat and throttle values for the input and output network variables. This tab contains the following fields:

Input Heartbeat Determines the interval (in seconds) the network

variables that have the Use Heartbeat option selected will wait for a heartbeat before detecting a heartbeat failure.

Use Heartbeat Determines whether the associated input network

variable uses heartbeat checking. The buttons allow you to enable heartbeat checking for all input network variables or none of the input network variables, respectively.

Output Heartbeat Determines the output heartbeat, in seconds, for the

A_Out and Digital_Out network variables. This is

the maximum amount of time that may pass between network variable updates. Set this value to zero to disable heartbeats.

Throttle Determines the throttle, in milliseconds, for the

A_Out and Digital_Out Output network variables.

This is the minimum amount of time between

All and None

8-10 Analog Function Block Functional Block

Status

network variable updates. When the throttle time expires, only the most recent change to the output value is transmitted. Set this value to zero to disable throttling.

This tab allows you to view and change the status of an AFB functional block. See Status in Chapter 2 for more information.

The LonPoint Application and Plug-in Guide 8-11 8-12 Analog Function Block Functional Block

The PID Controller Functional

Block: Application and Plug-in

This chapter describes how to configure a PID controller functional block using the LonPoint Plug-in.

The LonPoint Application and Plug-in Guide 9-1

The PID Controller Functional Block

The PID Controller functional block controls an output network variable value based on an input process variable and setpoint. The process variable is obtained from a sensor that measures an environmental condition, such as temperature or air pressure. The setpoint indicates the desired value of the process variable. The PID controller reads these values and based on the PID algorithm, outputs a value known as the controlled variable. This variable is used to drive an actuator that effects the environmental condition which is read by the sensor that produces the process variable.

For example, a PID functional block may be used to control the temperature of a room. The process variable would be connected to a sensor that reads the current temperature of the room, the setpoint would be determined manually through the use of a dial or control panel, and the controlled variable would be connected to an actuator that drives a VAV damper.

The following figure and tables summarize the inputs and outputs of the AFB functional block:

Input Network Variables

Default name Default type Description

PV SNVT_temp_f

(changeable)

SP SNVT_temp_f

(changeable)

Auto_Man SNVT_switch The auto/manual network variable.

Man_Value SNVT_lev_cont_f The manual value network

Mode SNVT_hvac_mode

(changeable)

The process variable network variable.

The setpoint network variable.

If this network variable is set to On, the PID controller will be in Auto. If this network variable is set to Off, the PID controller will be in manual. See the more information.

variable. See the more information.

The mode network variable. See the Presets tab for more information.

Presets tab for

9-2 PID Controller Functional Block

Enable SNVT_switch The enable network variable. If

this network variable is set to On, the PID Controller functional block will function normally. If this network variable is set to Off, the output network variables on this functional block will return to their defaults.

Output Network Variables

Default name Default type Description

CV SNVT_lec_cont_f The control variable network

variable.

SP_Out SNVT_temp_f

(changeable)

Auto_Man_Out SNVT_switch The auto/manual output network

The setpoint output network variable. This network variable outputs the setpoint being used by this PID Controller. This may differ from the value aquired from the SP network variable. See the

Presets tab for more information.

variable. If this network variable is set to On, it indicates that this PID Controller is functioning in Auto. If this network variable is set to Off, it indicates that this PID controller is operating in Manual. See the

Presets tab for more information.

Configuring a PID Controller with the LonPoint Plug-in

Right-click the functional block shape and select Configure from the shortcut menu to open the PID window of the LonPoint Plug-in. This window contains the following tabs:

Parameters, Heartbeats, and Status.

PID, Input Defaults, Presets, PID Coefficients, Output

The LonPoint Application and Plug-in Guide 9-3

PID

This tab appears as follows:

This tab displays the flow of information through the PID functional block. The input values are taken from network variables on the left. The information is passed through the preset tables to determine what values are sent to the PID controller. The PID controller calculates the controlled variable and outputs it to the controlled variable network variable on the right, along with the actual setpoint and auto/manual settings used.

Invert option specifies whether or not the Enable input is inverted. If Invert

The is checked, the PID functional block is enabled when the Enable network variable is set to Off.

9-4 PID Controller Functional Block

Input Defaults

This tab appears as follows:

This tab sets the default input values for the input network variables. As described in Default Values in Chapter 1, these values will be used if the corresponding input network variables are not connected, or have not received an update since the last device reset. The types of the depend on the types selected or the corresponding network variables on the PID tab.

Process Variable, Setpoint, and Mode values

The LonPoint Application and Plug-in Guide 9-5

Presets

This tab appears as follows:

This tab configures the preset tables. Each preset table can contain up to 16 entries. The configured. When the PID is running, the preset tables are indexed by the PID’s

Mode network variable to determine which value will be used.

Each entry in a preset table specifies the source of the value controlled by the preset. The source for each value may be the associated network variable or a fixed preset value. If variable is used. If corresponding preset field is used (i.e., the network variable is not used).

Auto/Manual presets determines whether the PID is in Auto or Manual

The operation for this mode. When the PID controller is in Auto operation the PID Controller will attempt to make the process variable equal to the setpoint. When the PID controller is in value indicated by the bypassed). This allows you to create a preset in which the controlled variable is set to a value sent to the PID through the preset value.

Manual Value and Setpoint presets determine how these values are

The obtained. They can be read from their corresponding network variables or set to a

View Mode field determines which one of the entries is currently being

Use Network Variable is selected, the value from the network

Use Preset Value is selected, the value entered in the

Manual operation the controlled variable will be set to the

Manual Value preset table (i.e., the PID Controller will be

Manual Value network variable or to a

9-6 PID Controller Functional Block

preset value. The Manual Value will only be used when the Auto/Manual value is set to

Manual, and the Setpoint will only be used if it is set to Auto.

PID Coefficients

This tab appears as follows:

This tab sets values that effect the algorithm used by the PID controller. This tab allows you to set that following configuration properties:

P The proportional term of the PID controller. Its units

are percent output per process variable unit as specified on the PID tab. For example, if the process variable units are degrees C, then the units of this property are percent output/degree C.

I The integral term of the PID controller. A larger value

results in a smaller action (output change per scan). Its units are seconds. Enter 0 to disable this coefficient.

D The derivative term of the PID controller. A larger

value results in a larger action. Its units are seconds. Enter 0 to disable this coefficient.

The LonPoint Application and Plug-in Guide 9-7

Bias Sets the controlled variable output for a P-only

controller when there is zero error. This is only used if the integral (I) term is 0.

Deadband When the difference between the setpoint and the

process variable is less than this value, no controlled variable adjustment is made. The process variable is considered close enough. Deadband may be used to reduce actuator wear.

Cascade Causes the controlled variable to react more strongly to

changes in the setpoint for the PI and PID configurations. If you need to track setpoint changes quickly, turn Cascade on. If you want good response to load disturbances and setpoint response is less important, turn Cascade off.

This is option is called Cascade because when PID controllers are in a cascaded configuration, with the outer PID's controlled variable feeding the inner controller's setpoint, setpoint changes to the inner controller are as important as process disturbances. Make sure to turn Cascade on for the inner controller in a cascade arrangement.

When this option is set, two changes are made to the control algorithm: The setpoint value is not used when proportional contribution is calculated and the derivative contribution is given by instead of d/dt(PV).

d/dt(error)

Reverse Acting Process Specifies whether or not the process is reversing. If an

increase to the controlled variable causes the process variable to decrease, then the process is considered to be reversing. The process includes the sensors and actuators. A simple open-loop test can be made to determine how to set this property. Put the controller in override and wait for the process variable to stabilize, then increase the override value. If the process variable decreases, the process is reversing.

See LonPoint PID Controller Tuning, later in this chapter, for more information on setting these values.

9-8 PID Controller Functional Block

Output Parameters

This tab appears as follows:

This tab sets properties that effect the value output from the PID controller, and also determines the override values.

Max Slew Rate Limits how fast the controlled variable output can

change. This limit is in effect only during soft start. Soft start begins when the functional block is reset and it ends when the process variable value reaches the setpoint. Units are percent output change per scan interval (set in the

A value of 0 disables slew rate limiting (a value of 100 or greater also disables limiting since the output can change across the whole range each time the PID executes).

High Limit/Low Limit Determines the upper and lower limits for the

controlled variable. If the PID tries to set the controlled variable to a value outside of this range, the value will be clipped to the specified limit.

Heartbeats tab).

The LonPoint Application and Plug-in Guide 9-9

Default Values The default value for the controlled variable output.

This value will be set in case of a heartbeat failure or if the PID is disabled using the

Controlled Variable Override Sets the value of the controlled variable output when

this PID functional block is put into override mode.

Enable input.

Actual Auto/Manual OverrideThe

whether the PID is in Auto (On output) or Manual (Off Auto_Man_Out output) operation. In situations where PID controllers are cascaded, with the inner-loop controller taking its setpoint from an outer-loop controller’s variable, the outer-loop controller must know the

Auto/Manual setting of the inner loop controller.

This is illustrated in the following figure. When the inner loop controller is in override, it is not controlling and is in

This configuration property determines the value of the functional block is put into override. Set the value to

Manual to accurately reflect the actual auto/manual

setting when the PID is in override.

Auto_Man_Out network variable indicates

Auto_Man_Out

CV network

Manual operation.

Auto_Man_Out output when this PID

9-10 PID Controller Functional Block

Heartbeats

This tab appears as follows:

This tab determines input and output heartbeats, as well as the execution rate of the PID controller.

Input Heartbeat Determines the interval (in seconds) the network

variables that have the Use Heartbeat option selected will wait for a heartbeat before registering a heartbeat failure.

Use Heartbeat Determine whether the corresponding network variable

checks its heartbeat. Click the All or None buttons to enable heartbeat checking for all input network variables or none of the input network variables, respectively.

Scan Interval Indicates how often (in milliseconds) the PID controller

will execute (i.e. compare the setpoint and the process variable and send a value to the controlled variable). This may be set to 0.5 sec, 1 sec, 2 sec, 4 sec, 8 sec, 16 sec, or 32 sec.

Output Heartbeat Determines how often the output network variables

send a heartbeat. The expected heartbeat rate and

The LonPoint Application and Plug-in Guide 9-11

failure conditions are determined by the functional blocks that contain the corresponding input network variables.

Status

This tab allows you to view and change the status of a PID controller functional block. See Status in Chapter 2 for more information.

LonPoint PID Controller Tuning

This section describes a simple method that can be used to set initial values for the PID coefficients. An open-loop experiment is done to determine the static gain and the basic dynamic properties of the process being controlled. These values are entered into a program that calculates the P, I, and D coefficients for the PID controller. The coefficients are loaded into the PID controller using the LonPoint Plug-in and the LonMaker for Windows Integration Tool. The coefficients match or tune the controller for the controlled process.

Figure 8.1 shows an example PID loop for reference. The Analog Inputs come in from the left and connect to the PID setpoint (SP)and process variable (PV) inputs. AI- 2 controls the setpoint, which can range from zero to one hundred percent. In practice the setpoint and process variable will be in terms of some engineering unit, temperature in degrees C for example. The PID calculates the control value, CV, and sends it to the Analog Output, AO- 1. AO- 1 is wired to an actuator that drives the plant or process. The process is sampled by the Analog Input, AI- 1, and connecting this back to the PV input of the controller closes the loop.

In this example there are unconnected inputs on the PID. When inputs are not connected, default inputs values are used. These defaults can be set on the Input Defaults tab.

Figure 8.1 PID Example Drawing

To calculate the PID coefficients, you can perform an experiment. To do the tuning experiment, put the PID controller into manual mode, set the manual value and wait for the sensed process variable to reach equilibrium. Then the manual value is changed to a different value; this is the ‘step’ part of the experiment. The proper step size depends on the controlled process. With some trial and error experience, it should not be difficult to choose a reasonable step size. The largest

9-12 PID Controller Functional Block

possible step is not necessarily better than a small step; you have to wait longer for the large step to reach its new process value. Too small of a step will make it too hard to see when the process has settled. This example uses a 20% step size.

To perform the experiment and calculate the PID coefficients, follow these steps:

Open your design with the LonMaker tool, making sure to put your network

1. OnNet.

Right-click the PID controller function block and select Browse from the context

2. menu.

Use the Delete key to remove unnecessary data from the Browser window.

3. Leave just the rows as shown below.

Change the value of the Auto_Man input by entering 0.0 0 in value field.

Set the Man_Value network variable to the initial value for the experiment.

5. The example shows manual mode, and forces its control output to 40%.

Right-click the PV network variable and select Monitor Value to turn on

6. monitoring of the process.

Wait for the process reading to stabilize.

Record the manual value and the process variable. For the example, these are

8. 40% and 39%.

Man_Value as 40%. This puts the PID controller is in

Change the Man_Value network variable to a new value. This example uses

60.

Wait for the process to stabilize and record the data. For this example the

10. results are 60% and 63.11%.

Change Man_Value back the original setting, 40% for this example. The

11. process will stabilize.

The LonPoint PID Tuning Calculator calculates the PID coefficients from the raw data. Once the readings are known. This gives the static process gain; we know how much the process variable changes for a given change in the control variable. The process

Man_Value step is done, the initial and final process variable

The LonPoint Application and Plug-in Guide 9-13

variable delta, delta PV, is the difference between the final and initial process variable readings; the control variable step causes a process variable change of

delta PV.

In the next part of the experiment, the dynamic properties of the process are found. There are two time intervals that need to be measured. They are named T1 and T2. Both intervals start when the control variable step change is made. T2 is the time required to attain 28.8% of delta PV. T1 is the time required to reach 63.2% of delta PV. These specific percentage values are dictated by the two-point tuning method used in this example.

To start the LonPoint PID Tuning Calculator, open the Windows Start menu, select the LonPoint Device Software program folder, then select PID calculator. Enter the CV and PV data as shown below. Make a note of the PV at T2 and PV at T1 values. This says that T2 is defined as the time it takes for the process variable to reach a value of 44.66. T1 is the time it takes to reach 51.76.

In this part, we will step the process again, watch for the process variable to reach the PV at T2 and PV at T1 values, and record the T1 and T2 times:

Using the LonMaker Browser, change the Man_Value network variable to the

1. step value and start timing. This example uses a final step value of 60.

Watch the process variable, which is being monitored, to see when it reaches

2. the calculated T2 value; 45 in this example.

Record the time and keep watching PV, record the time when the T1 value is

3. reached; 52 in this example.

9-14 PID Controller Functional Block

4. Enter the T1 and T2 times into the calculator and click the Calculate button. The PID coefficients are shown in the grid:

The various options are shown in the left-hand column. Sets of coefficients for a Ponly controller, a PI controller and a PID controller are shown. Blanks represent zero values for the associated parameters. For example, if you want a PI controller, set P = 8.45, I = 3.80, and D = 0.

The LonPoint Application and Plug-in Guide 9-15

Go back to the LonMaker tool to configure the PID. Right-click the PID Controller functional block and select Configure from the shortcut menu. Enter the PID coefficients using the PID coefficients tab as shown below.

A cascade arrangement is where an outer PID controller’s control variable is used to drive the setpoint of an inner PID controller. The inner controller must react strongly to changes in its setpoint.

To make the PID controller react strongly to changes in setpoint, check even if a cascaded PID is not being used. Normally, precise tracking of setpoint changes is less important that good tracking across process disturbances. is unchecked in this example.

An increase in the I-term gives less action. An increase in the D-term gives more action. A controller with more action will react more strongly to a given error.

Cascade –

Cascade

9-16 PID Controller Functional Block

Echelon LonPoint Application and Plug-In User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents