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Doc. Name: PRODUCT REQUIREMENT SPECIFICATION

forCONTROL SYSTEM CONFIGURATOR

PROJECT: ASTeC – Systems - CONTROL SYSTEM CONFIGURATOR

PRODUCT: Systems – Flexible Open SCADADoc No.: DRS CI 162 4301Control Status: Controlled Mastercopy if read from cvs Copy No:

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Table of contents

SL. No Contents Page No.

1. Introduction 11.1 Name of the Product 11.2 Product Mnemonic 11.3 Abbreviations 1

1.4 Reference 12. General Description 2

2.1 Product Perspective 3 2.2 Product Functions 3 2.3 Product Specification 3 3. Specific Requirements 4 3.1 Configuration 4 3.1.1 Configuration of Control System / Hardware 4 3.1.1.1 Configuration of General Purpose Controllers 5 3.1.1.1.1 Configuration of I/O cards 5 3.1.1.2 Configuration of Single Board Controller 6 3.1.1.3 Configuration of Low Power Controller 7 3.1.1.4 Configuration of Multiple Controller 8 3.1.2 Configuration of Control Schemes 8 3.1.2.1 Control Strategy using Functional Block Logic 8 3.1.3 Configuration of network and communication protocol 11 3.2 Download configuration 12 3.3 Upload configuration 12 3.5 Import/Export Utility 12 4. List of Annexure 13

Annexure A - IEC 61131-3: A Standard Programming Resource 14Annexure B - List of blocks with details 24Annexure C - Modbus TCP and DNP3 75

Doc. Name : Product Requirement Specification for Control System Configurator

Doc. No. DRS CI 162 4301 Doc Issue No:01

1. Introduction

1.1. Name of the Product: CONTROL SYSTEM CONFIGURATOR

1.2. Product Mnemonic : CSCONFIG 1.3. Abbreviations

TCP - Transmission Control Protocol or Transport Control Protocol,

IP - Internet Protocol

RTU - Remote Terminal Unit

PLC - Programmable Logic Controllers

I/O - Input/Output

IEC - International Electrotechnical Commission

ST - Structured Text

FBD - Functional Blocks Diagrams

SFC - Sequential Function Chart

IL - Instruction List

FB - Functional Blocks

DNP3 - Distributed Network Protocol

1.4. Reference

Programming Industrial Control Systems using 1131-3 (Revised edition) -

R.W. Lewis, Published by : The Institution of electrical Engineers, London,

United kingdom

International Standard CEI IEC 1131-3(first edition) - Programmable Controllers –

Part-3 : Programming languages - IEC Publication

Prepared by Technical Committee No. 65

Doc. Name: Product Requirement Specification for Control System Configurator1Doc. No. DRS CI 162 4301 Doc Issue No: 01 Page No: 1

2. General Description

The opening of the control system to interface with general-purpose platforms and software

has made a major change in the way control systems will be engineered in the future.

Control System Configurator is used to configure the hardware and control strategy

required for the control system. The number of Controllers, the type of I/O cards used, the

I/O channel description along with the TAG name can be configured. Configuration of

control strategy is to be done according to the Functional Block Logic of IEC 61131-3

standard.

The IEC (International Electrotechnical Commission) 61131-3 standard is for the

improvement of programming techniques and control strategy for process industries.

This standard was setup to look at the complete design, installation, testing,

documentation, programming and communication. IEC 61131-3 standard provides flexible

language selection for expressing different parts of a control application. They are

Structured Text – ST, Functional Blocks Diagrams – FBD, Sequential Function

Chart – SFC, Instruction List –IL.

Structured Text – ST - a very powerful high level language with its root in Ada,

Pascal and C

Functional Block Diagram – FBD – A graphical language for depicting signal and

data flows through function blocks – reusable software elements

Functional Blocks – FB – A function block is a part of a control program that is

packaged so that it can be reused in different parts of the same program. It should be

regarded as basic building blocks of a control system.

Sequential Function Chart – SFC - A graphical language for depicting

sequential behavior of control system. It is used for defining control sequences that are

time –and event- driven.


Instruction List - IL - textual language resembles assembler. Instruction

List is a low level language that can be used to express the behavior of

functions, function blocks and programs, and also actions and transitions in sequential

function charts.

It consists of a series of instructions where each instruction is on a new line.

2.1. Product Perspective

Development of CONTROL SYTEM CONFIGURATOR

2.2. Product Functions

Control System Configurator is an IEC 61131-3 compliant software utility to configure

Control system components.

2.3. Product Specification

The SCADA system shall include data acquisition servers for establishing the I/O

interface between field devices such as Controllers, RTUs etc. The software shall

have the flexibility to permit easy configuration of the system in accordance with the

specific end user requirements as well as quick and easy modification by the end user in

the field.


3. Specific Requirements

Functional Requirements

3.1 Configuration

It should be possible to create a new configuration

It should be possible to edit an existing configuration

It should be possible to save a configuration

It should be possible to download a configuration

It should be possible to view tag values in a separate browser or on the control

logic diagram of configuration

Configuration shall provide a user validation for allowing only privileged users

Data Entry validation with respect to default data limits

Configuration can be classified into three categories :

1. Configuration of Control System/hardware

2. Configuration of control schemes

3. Configuration of network/communication

3.1.1 Configuration of Control System / Hardware

This includes the configuration of various subsystems used in the main control

system.

The module should be capable of adding areas depending on the control

functions.

Under each area it should be possible to add controllers developed as part of

the project ‘Embedded Controllers’.

It should be possible to remove controllers.

It should be possible to select the following types of controllers

a) General Purpose Controller

b) Single Board Controller


c) Low Power Controller

It should be possible to configure each controller

3.1.1.4 Configuration of General Purpose Controllers

The following properties of the controller should be configured.

o Selection of protocols for communication with PC –Modbus/DNP3

o Name of Controller

o Mac Address and IP Address of the controller

o Redundancy – Default / Redundant / Critical

(It defines how important the device for the SCADA system, and effects

what action should be taken upon failure of the device.)

o Slot address

o I/O slots - No of slots can be configured as

8 slots

16 slots

24 slots

o Sampling time – Scanning rate of Controller (default 10 ms)

It shall be possible to add and configure I/O cards

3.1.1.1. 1 Configuration of I/O cards

It shall be possible to configure the following properties of the I/O board:

Types of I/O cards (analog /digital) – slot configuration

Analog Output 8 channel

Analog Input 16 channel

Digital I/O – 5VDC, 24VDC,48VDC

Digital Input – 230VAC/DC


Should have facility to add new card types

Scan rate ( Scanning rate of I/O card) – should be selectable (Analog, Digital)

Update interval - should be selectable for digital and analog signals

(Update rate of signals)

Jumper address

Channel Configuration

o Hart I/O or Conventional I/O- (Channel Should be selectable)o It should be possible to select whether the channel is input or

output for DI/O board o Tags - Physical tags that are connected to the I/O card

o Tag properties

Tag name – Editable stereotypes for tagnames should be provided

Tag type – shall specify the type of the tag. i.e. Analog/Digital

Tag description – Description of the tag

Maximum value - the maximum value associated with the

particular analog tag. For Analog Tags the default value is 100

and for digital tags the default value is 1.

Minimum value - the minimum value that can be associated with

the particular tag.

3.1.1.4 Configuration of Single Board Controller






Jumper address


Channel Configuration

It should be possible to configure analog channels and digital channels

Tags - Physical tags

Tag properties








the particular tag.

3.1.1.3Configuration of Low Power Controller






Jumper address Channel Configuration

It should be possible to configure analog channels and digital channels

Tags - Physical tags, Virtual Tags ( for display)

Tag properties









the particular tag.

3.1.2 Configuration of Control Schemes

The configurator shall follow IEC 61131-3 standard for configuring control

schemes.

It should be possible to configure the control schemes to be run in each

controller.

The configurator shall provide facility to configure the control strategy usin

Functional Block Logic of the standard. (See Annexure A for more details)

Predefined control schemes should be made available in a library for the

users to select.

It should be possible to view tag values on the control scheme diagram

3.1.2.1 Control Strategy using Functional Block Logic

The configurator shall provide a GUI to create control schemes using

functional block logic. A library of function blocks will be

provided which contain the following blocks:

1. CINP - Analog Input Processor

2. LOGI - Digital Logic Operator

3. DINT - DIGITAL INTEGRATION BLOCK

4. ASW - Analog Signal Switch


5. AINT - Analog Integrator Block

6. SQRT - Square Root

7. FUNC - Function Generator Block

8. CPID - PID Block

9. ADSB - ADDITION SUBTRACTION BLOCK

10. MULD - MULTIPLIER/DIVIDER BLOCK

11. SELH - LOW/HIGH SELECTOR BLOCK

12. MPCG - Multi Point Constant Generator

13. HLMT - High/Low block

14. TLDT - Time Lag + Dead Time

15. DBOG - Dead Band Operator with Gain

16. LDLG - Lead Lag Block

17. OUTP - Output Processor Block

18. MLOG - Multiple Operator Logical Operator Block

19. PPID - Pulse PID

20. PEU - Percentage To Engineering Unit

21. EUP - Engineering Unit to Percentage

22. PTC - Pressure Temperature Compensator

23. PPC -PID To Pulse Converter

24. CNTR – Counter

25. MAVG - Moving/Fixed Average

26. PARA - Parameter Setter

27. CMP – Comparator

(Refer Annexure B for details)


It should be possible to add new function blocks to the library. For each

function block, it should be possible to configure the following :

o No. of Inputs

o No. of outputs

o Maximum inputs and outputs to a function block

Placing and movement of function blocks on the screen should be possible

Resizing of function blocks should be done the extent possible

It should be possible to check the validity of blocks

The control strategy is to be created by interconnecting the function blocks and

setting the parameters.

Interconnection should be possible between blocks in the same frame and also

between blocks in different frames.

Maximum No. of blocks in a frame -12

Max No. of loops for each controller - 50 ( H/w dependent)

Tags can be attached to parameters and function block outputs for

debugging purposes.

Library of commonly used control schemes shall be provided.

It should be possible to create composite function blocks by combining basic

function blocks.

It should be possible to add newly created composite function blocks to the

library.

Connectivity should be checked for compatibility

Each signal is connected to exactly one source.

This source can be the output of a function block or a plant signal.

The type of the output pin, the type of the input pin and the signal type must be identical.


3.1.3 Configuration of network and communication protocol

The network configuration includes:

Type of network (Serial, Ethernet)

Parameter assignments

Serial interface

COM port (RS 232, RS485, RS422)

Baud rate

Data Bits

Parity

Stop bit

Ethernet interface

IP address

MacAddress

Port No.

Type of network protocol

Modbus TCP - Modbus Protocol is a messaging structure used to establish

master-slave /client - server communication between intelligent devices

DNP3 - Distributed Network Protocol is a set of communications protocols

used between components in process automation systems

It should be possible to configure the types of protocol

(i.e. Modbus TCP or DNP3)

It should be possible to configure either master or slave


In case of Modbus TCP

Settings

Host address

Port

Mapping of Register and Coil addresses

Discrete Inputs- Start and End address

Coils-Start and End Address

Input Registers- Start and End Address

Holding Registers- start and End Address

In case of DNP 3

Settings

Host address

Port No.

Link Addresses

3.2 Download configuration

Before downloading, check the configuration for errors and see whether downloadable

system data can be created from the present configuration. Any errors found during

consistency checking are to be displayed in a window.

3.3 Upload configuration

It shall be possible to Upload into a New configuration

It shall be possible to Upload into an Existing configuration

3.5 Import/Export Utility

The Development Environment shall include a utility to support import or

export from external editors. (to be decided)


4 List of Annexure

Annexure A - IEC 61131-3 : a standard programming resource

Annexure B - List of blocks with details

Annexure C - Modbus TCP, DNP3


Annexure A

IEC 61131-3: a standard programming resource

IEC 61131-3 is the third part of the open international standard IEC 61131, and was first published

in December 1993 by the IEC. The current (second) edition was published in 2003.

IEC 61131-3 is the first real endeavor to standardize programming languages for industrial

automation. With its worldwide support, it is independent of any single company.

IEC 61131-3 is the third part of the IEC 61131 family. This consists of:

Part 1: General Overview

Part 2 Hardware

Part 3 Programming Languages

Part 4 User Guidelines

Part 5 Communication

Another elegant view is by splitting the standard in two parts:

1. Common Elements

2. Programming Languages


http://en.wikipedia.org/wiki/2003

http://en.wikipedia.org/wiki/International_Electrotechnical_Commission

http://en.wikipedia.org/wiki/1993

http://en.wikipedia.org/wiki/IEC_61131

http://en.wikipedia.org/wiki/International_standard

Common Elements

Data Typing

Within the common elements, the data types are defined. Data typing prevents errors in an early

stage. It is used to define the type of any parameter used. This avoids for instance dividing a Date

by an Integer. Common datatypes are Boolean, Integer, Real and Byte and Word, but also Date,

Time_of_Day and String. Based on these, one can define own personal data types, known as

derived data types. In this way one can define an analog input channel as data type, and re-use this

over and over again.

Variables

Variables are only assigned to explicit hardware addresses (e.g. input and outputs) in

configurations, resources or programs. In this way a high level of hardware independency is

created, supporting the reusability of the software. The scopes of the variables are normally limited

to the organization unit in which they are declared, e.g. local. This means that their names can be

reused in other parts without any conflict, eliminating another source of errors, e.g. the scratchpad.

If the variables should have global scope, they have to be declared as such (VAR_GLOBAL).

Parameters can be assigned an initial value at start up and cold restart, in order to have the right

setting.

Configuration, Resources and Tasks

To understand these better, let us look at the software model, as defined in the standard in the

figure.


At the highest level, the entire software required to solve a particular control problem can be

formulated as a Configuration. A configuration is specific to a particular type of control system,

including the arrangement of the hardware, i.e. processing resources, memory addresses for I/O

channels and system capabilities.

Within a configuration one can define one or more Resources. One can look at a resource as a

processing facility that is able to execute IEC programs. Within a resource, one or more Tasks can

be defined. Tasks control the execution of a set of programs and/or function blocks. These can

either be executed periodically or upon the occurrence of a specified trigger, such as the change of

a variable. Programs are built from a number of different software elements written in any of the

IEC defined languages. Typically, a program consists of a network of Functions and Function

Blocks, which are able to exchange data. Function and Function Blocks are the basic building

blocks, containing a datastructure and an algorithm.

Let’s compare this to a conventional PLC: this contains one resource, running one task, controlling

one program, running in a closed loop. IEC 61131-3 adds much to this, making it open to the

future. A future that includes multi-processing and event driven programs. And this future is not so

far: just look at distributed systems or real-time control systems. IEC 61131-3 is suitable for a

broad range of applications, without having to learn additional programming languages.


Program Organization Units (POU)

Within IEC 61131-3, the Programs, Function Blocks and Functions are called Program

Organization Units, POUs.

Functions

IEC has defined standard functions and user defined functions. Standard functions are for instance

ADD(ition), ABS (absolute), SQRT, SINus and COSinus. User defined functions, once defined,

can be used over and over again.

Function Blocks, FBs

Function Blocks are the equivalent to Integrated Circuits, ICs, representing a specialized control

function. They contain data as well as the algorithm, so they can keep track of the past (which is

one of the differences w.r.t. Functions). They have a well-defined interface and hidden internals,

like an IC or black box. In this way they give a clear separation between different levels of

programmers, or maintenance people.

A temperature control loop, or PID, is an excellent example of a Function Block. Once defined, it

can be used over and over again, in the same program, different programs, or even different

projects. This makes them highly re-usable. Function Blocks can be written in any of the IEC

languages, and in most cases even in “C”. In this way they can be defined by the user. Derived

Function Blocks are based on the standard defined FBs, but also completely new, customized FBs

are possible within the standard: it just provides the framework.

The interfaces of functions and function blocks are described in the same way:


The declarations above describe the interface to a function block with two Boolean input

parameters and one Boolean output parameter.

Programs

With the above-mentioned basic building blocks, one can say that a program is a network of

Functions and Function Blocks. A program can be written in any of the defined programming

languages.

Sequential Function Chart, SFC - has elements to organize programs for sequential and

parallel control processing.


http://en.wikipedia.org/wiki/Parallel_computing

SFC describes graphically the sequential behavior of a control program. It is derived from

Petri Nets and IEC 848 Grafcet, with the changes necessary to convert the representation

from a documentation standard to a set of execution control elements. SFC structures the

internal organization of a program, and helps to decompose a control problem into

manageable parts, while maintaining the overview. SFC consists of Steps, linked with

Action Blocks and Transitions. Each step represents a particular state of the systems being

controlled. A transition is associated with a condition, which, when true, causes the step

before the transition to be deactivated, and the next step to be activated. Steps are linked to

action blocks, performing a certain control action. Each element can be programmed in any

of the IEC languages, including SFC itself.

One can use alternative sequences and even parallel sequences, such as commonly

required in batch applications. For instance, one sequence is used for the primary

process, and the second for monitoring the overall operating constraints. Because of

this general structure, SFC provides also a communication tool, combining people of

different backgrounds, departments or countries.

Programming Languages


Within the standard four programming languages are defined. This means that their syntax and

semantics have been defined, leaving no room for dialects. Once you have learned them, you can

use a wide variety of systems based on this standard. The languages consist of two textual and two

graphical versions:

Textual: Instruction List, IL

Structured Text, ST

Graphical:

Ladder Diagram, LD

Function Block Diagram, FBD

In the above figure, all four languages describe the same simple program part.

The choice of programming language is dependent on:

the programmers’ background

the problem at hand

the level of describing the problem

the structure of the control system

the interface to other people / departments


All four languages are interlinked: they provide a common suite, with a link to existing experience.

In this way they also provide a communication tool, combining people of different backgrounds.

Ladder Diagram has its roots in the USA. It is based on the graphical presentation of

Relay Ladder Logic.

Instruction List is its European counterpart. As textual language, it resembles

assembler.

Function Block Diagram is very common to the process industry. It expresses the

behavior of functions, function blocks and programs as a set of interconnected graphical

blocks, like in electronic circuit diagrams. It looks at a system in terms of the flow of

signals between processing elements.

Structured Text is a very powerful high-level language with its roots in Ada, Pascal

and “C”. It contains all the essential elements of a modern programming language,

including selection branches (IF-THEN-ELSE and CASE OF) and iteration loops (FOR,

WHILE and REPEAT). These elements can also be nested. It can be used excellently for

the definition of complex function blocks, which can be used within any of the other

languages.


Also, the standard allows two ways of developing your program: top down and bottom

up. Either you specify your whole application and divide it into sub parts, declare your

variables, and so on. Or you start programming your application at the bottom, for

instance via derived functions and function blocks. Whichever you choose, the

development environment will help you through the whole process.

Implementations


The overall requirements of IEC 61131-3 are not easy to fulfill. For that reason, the standard

allows partial implementations in various aspects. This covers the number of supported

languages, functions and function blocks. This leaves freedom at the supplier side, but a user

should be well aware of it during his selection process. Also, a new release can have a dramatically

higher level of implementation. Many current IEC programming environments offer everything

you expect form modern environments: mouse operation, pull down menus, graphical

programming screens, support for multiple windows, built in hypertext functions, verification

during design. Please be aware that this is not specified within the standard itself: it is one of

the parts where suppliers can differentiate.

The technical implications of the IEC 61131-3 standard are high, leaving enough room for

growth and differentiation. This makes this standard suitable to evolve well into the next

century. IEC 61131-3 will have a great impact on the whole industrial control industry. It

certainly will not restrict itself to the conventional PLC market. Nowadays, one sees it

adopted in the motion control market, distributed systems and softlogic / PC based control

systems, including SCADA packages. And the areas are still growing. Having a standard over

such a broad application area, brings numerous benefits for users / programmers. The benefits for

adopting this standard are various, depending on the application areas. Just to name a few for the

mindsetting:

reduced waste of human resources, in training, debugging, maintenance and

consultancy

creating a focus to problem solving via a high level of software reusability

reduced misunderstanding and errors

programming techniques usable in a broad environment: general industrial control

combining different components from different programs, projects, locations,

companies and/or countries


Annexure B

List of blocks with details





5. AINT - Analog Integrator Block

6. SQRT - Square Root


8. CPID - PID Block

9. ADSB - ADDITION SUBTRACTION BLOCK

10. MULD - MULTIPLIER/DIVIDER BLOCK

11. SELH - LOW/HIGH SELECTOR BLOCK

12. MPCG-Multi Point Constant Generator


14. GSFG - Gradient Setting Function Generator

15. MSFG - Multi Stage Function Generator

16. TLDT -Time Lag + Dead Time

17. DBOG -Dead Band Operator with Gain


19. OUTP - Output Processor Block

20. PLSR - Pulser Block For Batching Operation

21. BTCH - Batching Operation

22. SEQ - Sequencer Block


23. MLOG - Multiple Operator Logical Operator Block

24. SINT - Sintering Block

25. AINP - Alarm Checking Input Block

26. MMDET - Maximum/Minimum Detector

27. NNET - Neutral Net Block

28. LCON - Loop Execution Controller

29. FOP - First Order Process


31. RLS - Recursive Least Square Estimator

32. RND - Random Signal Generator


34. EUP - Engineering Unit to Percentage

35. PRDT - Predictor Block


37. PPC -PID To Pulse Converter

38. CNTR – Counter

39. RTT - Real Time Trigger

40. MAVG - Moving/Fixed Average

41. PARA - Parameter Setter

42. ABS - Absolute Value Finder

43. STL - Statistical Function

44. LGM - Logarithm

45. RCL - Rate of Change Limitter

46. PLN - Polynomial Line Table For Linearisation

47. CMP – Comparator



This block is used to read analog input from physical channel and to process it after

reading the input the block executes the following functions on the input signal as per the

relevant parameter specification

Inputs

Input 1,is an analog signal, which is to be read and processed.

Outputs

Output 1 is an analog signal, which is the processed output signal.

Output 2 is the instrument alarm

Output 3 is the High-High alarm

Output 4 is the High alarm

Output 5 is the Low alarm

Output 6 is the LowLow

Output 7 is the Rate alarm

Parameters

P01: Instrument error checking. High limit in percentage.

P02: Instrument error checking. Low limit in percentage.

P03: Rate of change limit. Maximum change (in %) permitted per execution cycle.

P04: Process Maximum Value

P05: Process Minimum Value

P06: Engineering Units(Max 7 Chars)


P07: Process HIHI limit in percentage

P08: Process HI limit in percentage

P09: Process LO limit in percentage

P10: Process LOLO limit in percentage

P11: Filter time constants in seconds.

P12: Instrument error alarm enable(0-disable,1-enable)

P13: Process HIHI alarm enable(0-disable,1-enable)

P14: Process HI alarm enable(0-disable,1-enable)

P15: Process LO alarm enable(0-disable,1-enable)

P16: Process LOLO alarm enable(0-disable,1-enable)

P17: Process RATE alarm enable(0-disable,1-enable)

P18:Alarm hysterisis constant in percentage(common for all alarms)

P19:Square root extraction (0-NO,1-YES)



This block reads or writes digital signals from/to physical channels.One LOGI block can

take two inputs and it can execute any of the following logical function on the input

signals. The function selection is done by the parameter no 4.Apart from the logical

function,this block can detect alarm(status change) of both the inputs and output.If A and B

are the two inputs to block,then the output for diffrent function codes are as follows.

Inputs

D1: Digital input 1


D2: Digital Input 2

Outputs

Y: Digital output

D11: Input1 (d1) alarm status

D12: Input2 (d2) alarm status

D13: Output alarm status

Parameters

P01: In #1 Normal State (1/0)

P02: In #2 Normal State (1/0)

P03: Output Normal State (1/0)

P04: Function Code

P05: ON Time (seconds)

P06: OFF Time (seconds)

P07: Input #1 Alarm (1=Y, 0=N)

P08: Input #2 Alarm (1=Y, 0=N)

P09: Output Alarm (1=Y, 0=N)

P10: In #1 Normal State (Max 7 char)

P11: In #1 Alarm State (Max 7 char)

P12: In #2 Normal State (Max 7 char)

P13: In #2 Alarm State (Max 7 char)

P14: Output Normal State (Max 7 char)

P15: Output Alarm State (Max 7 char)

P16:Set trigger.

P17:Counter reload value



This block can be used to increment/decrement its output(Y) by a user defined step

size(delta Y) during each cycle of block execution. The step size is defined using the

block parameter P03.Increment/decrement action is decided by the value of digital inputs

D! and D2.When D1 is ON, the step size is added to the previous value of the output(Y 0).

When D2 is ON, the step size is subtracted from the previous value of the output. The

output will be reset to the value K1(as defined by the block parameter P04) when the

digital input D3 is ON. The output can be preset to the value K2(as defined by the block

parameter P05) by making the digital input D4 ON.

Inputs

D1 = Digital Input.

D2 = Digital Input.

D3 = Digital Input.

D4 = Digital Input.

Output

Y = Integrated analog output Parameters

P01: Output Low Limit (%)

P02: Output High Limit (%)


P03: StepSize Per Cycle : delta Y (%)

P04: Reset Value : K1 (%)

P05: Preset Value : K2 (%)


This block works as a digitally controlled switch for analog signals. So depending upon

some process conditions you can select the analog signal for computation, processing or

for outputing. There are two constants(Parameters 3 and 4)also provided as parameters

and selection will be between parameters if specified so.

Inputs

D1 : Digital input: Switching Control signal (acts as a control for the switch)

A1 : Analog input : Analog Input 1 (signal to be switched)

A2 : Analog input : Analog Input 2 (signal to be switched)

Output

Y : Switched analog output

Parameters

P01 : Select Analog #1/Const #1(1/0)

P02 : Select Analog #2/Const #2(1/0)

P03 : Const #1 (%)

P04 : Const #2 (%)


P05 : Ramp Rate(%)

5. AINT - Analog Integrator

The AINT block provides an analog output which is the integral of the input signal over a

period of time. It is basically used for computing the cumulative quantity of the material

used over a period of time by totalising the flow rate.

The analog signal corresponding to the flow rate is to be connected to the input A of the

block. Output represents the integrated value. Care should be taken to specify the high

and low range of the input flow rate to be totalised(P04 & P05)and the time base of the

input flow rate(P03) to get the integrated output correctly. The output of this block cannot

be connected to any other block. The tag fixed at the block output can be used for the

display purpose.

The analog output Y will be reset to the value K1(as defined by the parameter P01)when

the digital input D1 is ON. The output Y will be held at the previous value when the

digital input D2 is ON.

Inputs:

A Analog input signal to be integrated.

D1 When this input ON, the integrated output will be reset to a value K1.


D3 When this input ON, the integrated output will be held at the previous value.

Outputs:

Y Analog input signal to be integrated.

d11 This output will be set when the integrated output Y overflows or when it is reset

by the digital input D1.

Parameters:

P01 Reset Value of O/P:K1(engg.unit)

P02 O/P Overflow Limit:K2(engg.unit)

P03 Time Base(1=per Hour,2=per Minute)

P04 I/P(flow rate) High range(engg unit)

P05 I/P(flow rate) Low range(engg unit)

P06 Reset at 6 AM(N=No,else Yes)

P07 Process Maximum Value

P08 Process Minimum Value

6. SQRT-Square Root

Parameters

P01 C BIAS CONSTANT



The FUNC block generates an output which is a function of the input(Y=f(A1)).The

input/output relationship is defined with the help of block parameters in terms of a look-

up table. The output values for intermediate input points are computed by interpolation.

This block can be used to configure look-up tables for split ranging of signals or

linearisation. Linearization of temperature input is one typical application of this block.

The output pf thermocouple or RTD can be linearised with the help of this block. The

percentage temperature for the incoming millivolt signal at 0 tp 100% with an interval of

10% can be calculated and configured as the parameters of the FUNC block. this can

be used to find out the percentage temperature for a given percentage millivolt input.

Another typical application is the ranging of the signal going to the control valves. For

example, if we have two valves, to be operated for different range of flow by the output

of one controller, ie.first valve to operate in the range of 0% to 50% and second valve to

operate in the range of 50% to 100% of the controller output. This can be implemented by

using FUNC blocks.

Input

A1: Analog input


Output

Y: Analog output

Parameters:

P01: OUTPUT AT 0%. Output when input is 0%.










P11: OUTPUT AT 100%. Output when input is 100%

CPID - PID BLOCK


This block performs PID control action depending on the controller mode (P03) and the

values of the PID parameters set by the user. The CPID block is used for the regulation

control of the process variables. This block is normally used in the CINP-CPID-OUTP

combination. The block takes the incoming signal (Process Variable) PV and compares it

with the Set Value (SV) and executes the PID control algorithm and outputs the

Manipulated variable (MV).

Inputs

PV : Process Variable

SV : Remote (Cascade) Setpoint

D1 : Enable / Disable PID operation (0 = enable, 1 = disable)

D2 : Enable / Disable Setpoint tracking

Outputs

Y : PID output

D11 : Cascade mode opearation

D12 : Output High Alarm

D13 : Output Low Alarm

D14 : Deviation alarm

Parameters

P01: Direct/Reverse Acting (1/0)

P02: Set Point Value (%)

P03: Mode (0=A, 1=M, 2=C)

P04: Hysterisis Constant (%)

P05: Setpoint Ramp Rate (%)


P06: Proportional Gain Kp

P07: Integral Time Ti

P08: Derivative Time Td

P09: Output Hi Limit (%)

P10: Output Lo Limit (%)

P11: Deviation Limit (%)

P12: Master PID (1=Y, 0=N)

P13: Deviation Alarm (1=Y, 0=N)

P14: Output Limit Alarm (1=Y, 0=N)

P15: Valve Direction (1=DIR, 0=REV)

P16: Output Ramp Rate (%)

ADSB - ADDITION SUBTRACTION BLOCK

This block computes the arithmetic sum or difference of two or more analog signals. The

maximum number of inputs is limited to 4. Zero value(0) will be assumed for the

unconnected analog inputs in the computation.

Inputs

A1 = Analog input1

A2 = Analog input2

A3 = Analog input3


A4 = Analog input4

Output

Y = Processed analog output signal.

Parameters

P01: constant #1 (k1)




P05: Bias Constant, C (%)

P06: -ve Output Value (0=N, 1=Y)

MULD - MULTIPLIER/DIVIDER BLOCK

This block can be used to carry out multiplication or division operation on two analog

signals. The required arithmetic operation can be selected using the block parameter P01.

Unity value (1) will be assumed for the unconnected analog inputs in the computation.

Inputs

A1 = Analog input1

A2 = Analog input2


Output

Y = Processed Analog output

Parameters

P01: Computation Code (0 = MUL, 1= DIV)

P02: Gain Constant: K

P03: Bias Constant: C (%)

SELH - LOW/HIGH SELECTOR BLOCK

Inputs

A1 = Analog Input 1

A2 = Analog Input 2

A3 = Analog Input 3

A4 = Analog Input 4

Output

Y = Processed analog output signal

Parameters

P01: Function Code: CD (0 = LO, 1 = HI)


MPCG - Multi Point Constant Generator

P01 C1 CONSTANT WHEN D1 IS ONP02 C2 CONSTANT WHEN D2 IS ONP03 C3 CONSTANT WHEN D3 IS ONP04 C4 CONSTANT WHEN D4 IS ONP05 C5 CONSTANT WHEN D1,D2,D3,D4 IS OFF

This block is a constant generator equipped with constants at four points. Any of the

constants can be selected by proper combination of the digital signals D1..D4. If select

commands D1..D4 are not connected ,it functions as a single point constant generator and

outputs C5.D1 has highest priority and D4 lowest.

d11=1 if C1!=C2d12=1 if C3!=C4d13=1 if D1,D2,D3 & D4 are not connected



This block is used to limit the value of an analog signal within the high limit and low limit set by the user. The limits can be set using the block parameters P01 and P02.

Output Y=A if C2 < A< C1 Where A= Input signal =C1 if A>C1 C1 = High limit

=C2 if A< limit C2="Low">


14. GSFG - Gradient Setting Function Generator

P01 CD 0 FOR TIME TO BE TAKEN IN SECS 1 FOR TIME TO BE TAKEN IN MINS 2 FOR TIME TO BE TAKEN IN HRP02 C1 START POINT A1P03 C2 TARGET POINT A2P04 Ti TIME TO BE TAKENP05 ALPHA GRADIENT CONSTANT IF CD/Ti IS CHOSEN, ALPHA IS AUTOMATICALLY FIXED.P06 C2A ALARM OUTPUT ENABLE WHEN SET POINT IS REACHED.

When D1 is ON, output ramps to target point in time Ti specified.(D2 should be OFF)

When D1 is OFF then ramping is stopped. When D2 is ON output is reset to C1.

This is a computing block for generating a function having gradient specified by the

parameters CD and ALPHA. The start point and target point are given by inputs A1 and

A2. If A1&A2 are not connected parameters C1&C2 are taken as start point and target

point respectively.


15. MSFG-Multi Stage Function Generator

P01 CD CODE 0 FOR SEC 1 FOR MINP02 C CONSTANT TAKEN TO BE START POINT IF A1 IS NOT CONNECTEDP03 T1 TIME SETTINGP04 T2 TIME SETTINGP05 T3 TIME SETTINGP06 T4 TIME SETTINGP07 T5 TIME SETTINGP08 T6 TIME SETTINGP09 T7 TIME SETTINGP10 Y1 OUTPUT SETTINGP11 Y2 OUTPUT SETTINGP12 Y3 OUTPUT SETTINGP13 Y4 OUTPUT SETTINGP14 Y5 OUTPUT SETTINGP15 Y6 OUTPUT SETTINGP16 Y7 OUTPUT SETTING

This computing block generates functions with specified parameters when input D1 is '1'.Input A1 is the start point. For time=t1 the output ramps to Y1 and for the next time Y1 to Y2 and so on. If at any time D2 is on, output holds to the previous value.


16. TLDT-Time Lag + Dead Time

P01 T TIME CONSTANT IN SECP02 K GAIN CONSTANTP03 L DEAD TIME

This block computes first order LAG+DEAD time while receiving analog signals A1.

17. DBOG-Dead Band Operator with Gain

P01 C1 DEAD BAND ON +VE SIDEP01 C2 DEAD BAND ON -VE SIDEP03 K1 GAIN WITHIN DEADBANDP04 K2 GAIN OUTSIDE DEADBAND

WHEN INPUT IS WITHIN DEADBAND OUTPUT Y:K1*A1WHEN INPUT IS OUTSIDE DEADBAND OUTPUT Y: K2*(A1-C1)+K1*C1 .....(+VE) K2*(A1+C2)+K1*C2 .....(-VE)


This computing block performs dead band processing while receiving analog signal. It judges

whether input data is inside or outside deadband and provides output with gain specified by a

parameter.


This block provides lead/lag compensated input.

OutputY=K.1+T1s/1+T2s.A Where A=Input signal'T1=LEAD Time Constant T2= LAG Time Constant and T1/T2< 100


19. OUTP - Output Processsor Block

This block outputs the processed analog value to a physical tag (tag representing a

signal physically connected to the Analog Output module of RTU). It converts the

digitised value of the input signal (0-4000 counts) into the range used by the Analog

Output module (0-4096 counts).

Output Y=A.4096/4000 Where A=Input signal

This block can also be used to interconnect two or more loops using Loop-back Tag

(LPB Tag). The LPB tag fixed at the output of an OUTP block may be connected as

input to a block in another loop.


20. PLSR - Pulser Block For Batching Operation

P01 WS WEIGHING SCALE IN KGSP02 SP SETPOINT IN KGSP03 HTL HIGH TOLERANCE LIMIT %P04 LTL LOW TOLERANCE LIMIT %P05 SL1 SLOWING PRESET(00-20) IN KGSP06 SL2 SLOWING PRESET(20-40) IN KGSP07 SL3 SLOWING PRESET(40-60) IN KGSP08 SL4 SLOWING PRESET(60-80) IN KGSP09 SL5 SLOWING PRESET(80-100) IN KGSP10 ESL EMPTY SCALE LIMIT IN KGSP11 FC1 FLIGHT CORRECTION (00-20) IN KGSP12 FC2 FLIGHT CORRECTION (20-40) IN KGS


P13 FC3 FLIGHT CORRECTION (40-60) IN KGSP14 FC4 FLIGHT CORRECTION (60-80) IN KGSP15 FC5 FLIGHT CORRECTION (80-100) IN KGSP16 PON PULSE ON TIME IN SECSP17 POFF PULSE OFF TIME IN SECSP18 BTM BATCHING TIME IN SECS

This block is used for batching and weighing operations.It accepts one analog and

an enable command(D3) to manipulate the digital output Y and the four alarms which

indicate the various states of the batching cycle. The second input to the pulser is the

setpoint in percentage and the fourth ouput is the HALT signal. If the second input is

not connected the parameter specified as the setpoint will be taken for the batching

operation. When the HALT signal is on the pulser will stop the batching operations,

and the halted time will not be counted as batch time. Batching resumes when the signal

goes OFF.

21. BTCH-Batching Operation


This block is used for batching and weighing operations. It accepts one analog input and

an enable command(D3) to manipulate the digital outputs Y1,Y2 and the four alarms

which indicate the various states of the Batching cycle. This block is same as the pulser

block except that it has two control outputs namely FAST(Y1) and SLOW (Y2).

The second input to the batcher is the setpoint in percentage and the fourth input is the

HALT signal. If the second input is not connected the parameter specified will be taken for

the batching operation. When the HALT signal is ON the batcher will stop the batching

operations, and the halted time will not be counted as batch time. Batching resumes when

the HALT signal goes OFF.


A batching cycle starts on the high going edge of the enable input.A bin is considered to

be empty if the bin is less than the Empty Scale Limit(ESL).An empty bin is indicated by a

high signal on 'd13' output irrespective of whether the block is enabled or not.

The following functions are performed only when the enable input is high.

If 'A1' goes higher than the HighLimit(HL),Alarm 'd12' is set.

If A1 could not attain the set value(Low limit in this case)during the Maximun Batching

Time(BTM),alarm 'd14' is set.

Successful completion of the Batching operation is indicated by a high state of Alarm

'd15' (Batch Over).

If any of the above mentioned alarms namely d12,d14 or d15 is high,the block output is

permanently disabled for the current batching operation.

In the absence of any alarm condition ,the FAST outputs are activated until the Slowing

Limit(SL) is attained. At this point the FAST output goes OFF and SLOW output

continues till the Flight Corrected Value(FCV) is reached. FCV should be carefully

chosen so that the input reaches the lower tolerance limit after settling. However no

further action is taken if the limits are not attained.

22. SEQ-Sequencer Block


P01 A/M AUTO/MANUAL mode selector P1=1-AUTO;P1=0-MANUALP02 TE Transition edge selector P2=1-Low to High;P2=0-High to LowP03 OP1 P3=1,d11 enabled;P3=0 d11 disabledP04 OP2 P4=1,d12 enabled;P4=0 d12 disabledP05 OP3 P5=1,d13 enabled;P5=0 d13 disabledP06 OP4 P6=1,d14 enabled;P6=0 d14 disabledP07 OP5 P7=1,d15 enabled;P7=0 d15 disabledP08 OP6 P8=1,d16 enabled;P8=0 d16 disabled

D1 - Input for sequencing.Depending on P2 the sequencing will be done +ve edge -ve edge d11 - Sequence output 1d12 - Sequence output 2d13 - Sequence output 3d14 - Sequence output 4d15 - Sequence output 5d16 - Sequence output 6

This block does the function of sequencing the outputs as per the function of sequencing

the outputs as per the required pattern. The block has one input and six outputs. The

outputs can be sequenced(ie.made '1')one by one according to the parameter entered, on the

+ve/-ve edge of the input. Parameter 02 specifies the required edge for sequencing.

Parameters 03 to 08 are used to specify the outputs to be enabled during sequencing.

Parameter 03 corresponds to output 1 and parameter 08 corresponds to output 6.If the value

of the parameter value is '0' then the output will be skipped during sequencing. When the

mode is manual as set by parameter 01,all he outputs will be set to their respective

parameter value.


23. MLOG-Multiple Operator Logical Operator Block

The MLOG block is similar to the LOGI block, which can be used to perform any

one of the logic functions namely AND, OR NAND and NOR. Depending on the

requirement, the function code can be four digital signal can be connected to the input of

this block.

Inputs:


24. SINT-Sintering Block

P01 MAXIMUM VALUE OF SINT OUTPUTP02 MINIMUM VALUE OF SINT OUTPUTP03 TOTAL NUMBER OF WIND BOXESP04 MINIMUM DIFFERENCE BETWEEN TWO TEMPERATURES

Inputs:A1 - INPUT TEMPERATURE FROM LAST WIND BOXA2 - INPUT TEMPERATURE FROM (N-1)th WIND BOXA3 - INPUT TEMPERATURE FROM (N-2)th WIND BOX

OUTPUTS:Y - ACTIVE LENGTH OF SINTERING MACHINE

This block determine the active length of machine within which sintering process is

distribution curve of the last three wind boxes.Let Xm be the active length of the sintering


process.Suppose tn-2,tn-1,tn are the last three wind boxes,then active machine length Xm=tn-2-tn/2 *

(tn-2 * tn-1+tn)+15

25. AINP-Alarm Checking Input Block

26. MMDET-Maximum/Minimum Detector

P01 CD Control Code


P01 = 0 - Detect Maximum = 1 - Detect Minimum = 2 - Sample & Hold

This block is used to detect the maximum or minimum of an input signal. The block

has 3 inputs and one output.These inputs have the following definition.

D1 - Reset - If D1=1 the block is held in reset condition

and the internal variable are initialised.

ie. Y=0 if CD=0 or CD=2

Y=1 if CD=1D2 - Hold - If D2=1 the output of Y is held to its previous value.For normal working D2=0A1 - Analog inputY - Block Output

Y=0 if (D1=1) & CD=0 Y=100 if (D1=1) & CD=1 Y=0 if (D1=1) & CD=2 If D1=0 & D2=0 and CD=0 Y=A1 if A1>Y If D1=0 & D2=0 and CD=1 Y=A1 if A1< pre Y="A1" CD="2" and D2="0" & D1="0" If>

27. NNET-Neutral Net Block


28. LCON-Loop Execution Controller

P01 CD Logic Control ParameterP02 to P20 Loop No.whose execution is to be nabled/disabled

This is a general purpose loop control block which takes two digital inputs and gives a

digital output. The digital output is used to selectively enable or disable the execution of


a set of control loops. Depending on the inputs can be used for controlling the loop

execution. If the logical output Y=1 then all the loops as specified in parameter P02 to P20

will be enabled for execution. If the logical output Y=0,then all the loop specified by

the parameter P02 to P20 will be disabled.

The logic is defined as follows

IfCD=0 Y=0CD=1 Y=1CD=2 Y=D1&D2CD=3 Y=!D1&D2CD=4 Y=D1&!D2CD=5 Y=!D1&!D2CD=6 Y=D1+D2CD=7 Y=!D1+D2CD=8 Y=D1+!D2CD=9 Y=!D1+!D2CD=8 Y=(D1+Y) & !D2

If Y=0 all the loops specified in P02 to P20 are disabled. If Y=1 all the loops specified

in P02 to P20 are enabled.

29. FOP-First Order Process


Parameters:P01:T,Time constant in no of samples.P02:K,Gain Constant.P03:L,Dead Time in no of samples.

Inputs:A1:Input Signal

Outputs:Y:Block output

This block is used for simulation of a first order process using a time lag and dead time.


Parameters:

P01:DR:CONTROLLER ACTION DIRECT/REVERSE.

P02:MD:MODE 0-AUTO 1-MANUAL 2-CASCADE.

P03:SV:SET VALUE.

P04:HS:HYSTERISIS CONSTANT FOR ALARM.

P05:DH:DEVIATION HIGH LIMIT.

P06:DL:DEVIATION LOW LIMIT.

P07:KP:GAIN CONSTANT.

P08:TD:DERIVATIVE TIME CONSTANT.

P09:TI:INTEGRAL TIME CONSTANT.

P10:DHA:DEVIATION HIGH ALARM ENABLE.


P11:DLA:DEVIATION LOW ALARM ENABLE.

P12:D/M:DEVIATION?MEASURED VALUE INPUT.

P13:MO:MANUAL OUTPUT.

P14:CONTROLLER CONSTANTS INT/EXT.

P15:NUMBER OF LEARNING CYCLES.

P16:CHANGE IN PID O/P.

P17:INCREMENT(forcing in manual mode).

P18:DECREMENT(forcing in manual mode).

P19:VALUE POSITION HIGH LIMIT(%).

P20:VALUE POSITION LOW LIMIT(%).

Inputs:

A1:Measured Variables A2..A4:External Constants P1,P2,P3

Outputs:

Y:Controller output d11:Deviation High Alarm d12:Deviation Low Alarmt d13:Mode

Indication d14:Learning Mode

31. RLS - Recursive Least Square Estimator

Inputs:A1:PLANT INPUT A2:PLANT OUTPUT D1:START ESTIMATION D2:LEARNING MODE


Outputs:

P1,P2,P3 tuning constants for velocity mode PID controller

The RLS block computes the optimum value of the controller constants for a PID controller

based on an estimate of the plant parameters through Recursive Least Squares

(RLS)technique. The outputs P1 ,P2 and P3 can be connected to PID controller which

controls the plant .The plant input and output are connected to the inputs A1 and A2

respectively. When the D1 input goes from LOW to HIGH a fresh estimation cycle starts.

When input D2 is high ,the internal proceeds but the outputs P1,P2 and P3 are held

constants.

32. RND:Random Signal Generator

Parameters:P01:NL,max noise level peak to peak in %P02:C,Bias Constant in %

Inputs:None Outputs:Y : Block Output

This block is used for generating a Random Noise Signal whose amplitude and bias can be set using the block parameters.



Parameters:

P01:EURH:ENGINEERING UNIT RANGE HIGH

P02:EURL:ENGINEERING UNIT RANGE LOW

P03:PHH:PROCESS HIGH HIGH LIMIT

P04:PH:PROCESS HIGH LIMIT

P05:PL:PROCESS LOW LIMIT

P06:PLL:PROCESS LOW LOW LIMIT

P07:PHHA:PROCESS HIGH HIGH ALARM OUTPUT ENABLE

P08:PHA:PROCESS HIGH ALARM OUTPUT ENABLE

P09:PLA:PROCESS LOW ALARM OUTPUT ENABLE

P10PLLA:PROCESS LOW LOW ALARM OUTPUT ENABLE

P11:HYST:HYSTERESIS CONSTANT

The function performed in this block is percentage to engineering conversion.

When an abnormality is detected in any of the limit checks ,the corresponding alarm is

activated.The alarms may be connected to a physical tag,input of another blck or it can be

left unconnected.

d11-process high high alarm

d12-process high alarm

d13-process low alarm

d14-process low low alarm

Y=(EURH-EURL) * A1 / 100 + EURL


34. EUP:Engineering Unit to Percentage

Parameters:

P01:EURH:ENGINEERING UNIT RANGE HIGH

P02:EURL:ENGINEERING UNIT RANGE LOW

The function performed in this block is engineering unit to percentage conversion.

Y=(A1-EURL)/( EURH-EURL) * 100

35. PRDT-Predictor Block

Parameters:

P01:Tp,Prediction Period in secs

Inputs:

A1:Input Signal

Outputs:

Y:Block output,ie predicted value of the input signal

This block predicts the value of the input signal after a time Tp using the method of

least estimation.



Parameters:

P01:TRH:TEMPERATURE RANGE HIGH

P02:TRL:TEMPERATURE RANGE LOW

P03:PRH:PRESSURE RANGE HIGH

P04:PRL:PRESSURE RANGE LOW

P05:C1:CONST FOR ABS PRESS CONV

P06:C2:CONST FOR ABS TEMP CONV

P07:DP:DESIGN PRESSURE

P08:EURL:DESIGN TEMPERATURE

Inputs:

A1:FLOW(%)

A2:TEMPERATURE(%)

A3:PRESSURE(%)

These input terminals should be used only for the designated signals.

This block provides presure and temperature compensation.The pressure compensation

factor is calculated using the relation

PCF=(EU(PRESS)+C1)+(DP+C1).

The temperature compensation factor is calculated using the relation

TCF=(DT+C2)/(EU(TEMP)+C2).

The corrected flow is calculated using the relation


Y=SQRT(A1 * PCF * TCF) * 10.

If the pressure or temperature input is left unconnected,then the corresponding

compensation factor is set equal to 1.If the flow input is left unconnected,then A1 is set

equal to 0.

In the equation for calculating the corrected flow,the resulting value is multiplied by

10.This is done to correct the scaling error.

37. PPC-PID To Pulse Converter

Parameters

P01:Sampling rate the at which the PPC algorithm is to be executed.Normally set to 1 for

exceeding the algorithm every cycle.

P02:Percentage PID output change corresponding to one cycle ON pulse. P03:Settling

time,to be used with process having large response time.

Inputs

A1:Analog input,which is normally the output of a controller.

A2:Analog input giving position of the final control element.

Outputs

Y:Digital signal normally used as the pulse to increase the final control element position

d11:Digital signal normally used as the pulse to decrease the final control element

position.

This block is provided for converting the output of a PID controller to digital signal

to operate final control elements which need pulses to increase and decrease the

controlled variable. For example there are valves with actuators which responds to


increase or decrease pulses instead of continuous 4-20ma signal. This block generates

two different signals or output pulses, with the number of pulses and width being

proportional to the PID output. A second input is provided to read the final control

element position, and the PPC block always tries to match both the inputs by adjusting

the output pulses. In case the valve position input is not available from the field, PPC

will generate pulses as per parameter 02,making the final control element position

match with the PID output.

38. CNTR-Counter

Parameters:P01 Maximum Value of the Counter OutputP02 Minimum Value of the Counter OutputP03 Counter Output ValueP04 Counter up for rising(0)/Falling(1) edgeP05 Counter down for rising(0)/Falling(1) edgeP06 Reset ValueP07 Preset ValueP08 Alarm Enable(I/O)P09 High Alarm LimitP10 Low Alarm LimitInputs:D1 Count Up InputD2 Count Down InputD3 Reset Input


D4 Preset InputOutputs:Y Count Outputd11 High Alarm Outputd12 Low Alarm Output

This block can be used as general purpose counter. This block counts up or down

depending upon the incoming signals at D1 and D2.It counts up for the rising edge or for

falling edge of D1 as per the specification in the parameter P04 and it counts down for the

rising edge or falling edge of D2 as per the specification in parameter P05.D3 and D4 are

used for resetting and presetting the counter output. The high alarm and low alarm limit is

also provided for high/low alarm checking and high alarm(d1) and alarm(d12) outputs are

also provided.

39. RTT-Real Time Trigger

Parameters:

P01 Seconds Trigger Time(00-59)P02 Minutes Trigger Time(00-59)P03 Hours Trigger Time(00-23)P04 Trigger on Time in No of Cycles

Inputs:A1 Seconds Trigger InputA2 Minutes Trigger InputA3 Hours Trigger Input


Outputs:d11 Seconds Trigger Outputd12 Minutes Trigger Outputd13 Hours Trigger Outputd14 HH:MM:SS TriggerThis block is used to co-relate the logic configured in the loop with real time clock.It can

be used to reset/restart the logic/counters/ integrators configured.

A pulse with the width(for no of cycles)specified at P04 will be generated at d11 when the

'seconds' (SS) in the real time(HH:MM:SS) becomes equal to A1 or P01(if A1 is

unconnected).d12 will be ON for no of cycles specified at P04 when the 'minutes'(MM) in

the real time (HH:MM:SS) becomes equal to A2 or P02(if A2 is not connected).Similarly

d13 will ON for no of cycles specified at P04 when the 'hours'(HH) in the real time

(HH:MM:SS) becomes equal to A3 or P03(if A3 is not connected).

The fourth output,d14,will be ON for no of cyckes specified at P04 when all the three ,ie

seconds(SS),minutes(MM) and hours(HH) matches with A1/P01.A2/P02 and A3/P03

respectively.One typical application for this output is the initialization of the counters and

integrators at the beginning of the shift or day

40. MAVG-Moving/Fixed Average

This block computes the average of the incoming signal continuously or for a fixed


number of latest samples. f the parameter 1(P01) is zero, hen the block continuously

updates the average computed with every new samples read. n this case, input 1 can be

used to initialise or reset the output to the specified

In parameter 3(P03).If the parameter 1(P01) is specified as 1, then the block computes the

average of the last few (Parameter 2) inputs. When a new value is read into this queue of

few last samples, the oldest will be ignored.

Input 1 is a digital signal ,which initialise/reset signal for the block.

Input 2 is an analog signal, for which the averaging computation has to be done.

Output, is an analog signal, which is the average or moving of the input signal.

Parameter 1(P01):Set to '0' for continuous averaging and '1' to moving average.

Parameter 1(P02):No of samples to be used for moving average computation.

Parameter 1(P03):Reset/Initialise value.

Parameter 1(P04):Enable/Disable flag.

41. PARA-Parameter Setter

This block is used automatically set the parameters of other blocks to any desired

value. This block gets actuated with a rising edge in the first signal. For example, this

block can be used to automatically change the mode of the controller(which is a

parameter of the PID block) or alarm limit of an incoming signal etc. conditionally. Once


when this block gets actuated, it can be set a maximum of three parameter in other blocks

which may be in different loops. The value to which the parameters has to be set be

decided by parameters P10,P11, and P12 or the input signals 2,3 and 4.

Input 1,is a digital signal ,which is the 'condition' by which the block is getting actuated.

i.e.a rising edge of this input will set the three parameter specified by the parameters P01

to P09 to the values specified in P10 to P12.

Input 2,Input 3 and Input4 are the three incoming values, if connected, to which the

parameters has to be set when the block gets actuated.

There is no Output signal for this block.It only executes the parameter setting job during

the execution cycle in which it detects a rising edge in the input1.

Parameter 1(P01):Loop no of the first parameter to be modified.

Parameter 2(P02):Block no of the first parameter to be modified.

Parameter 3(P03):Parameter no of the first parameter to be modified.

Parameter 4(P04):Loop no of the second parameter to be modified.

Parameter 5(P05):Block no of the secon parameter to be modified.

Parameter 6(P06):Parameter no of the second parameter to be modified.

Parameter 7(P07):Loop no of the third parameter to be modified.

Parameter 8(P08):Block no of the third parameter to be modified.

Parameter 9(P09):Parameter no of the third parameter to be modified.

Parameter 10(P10):Constant 1(To which the first parameter to be changed) .

Parameter 11(P11):Constant 2(To which the second parameter to be changed).

Parameter 12(P12):Constant 3(To which the third parameter to be changed).


42. ABS - Absolute Value Finder

This block gives the absolute value of the input signal, i.e.the output will be equal to the

magnitude of the input signal irrespective of the input signal.

Input1 is an analog signal for which the absolute value has to be found.

Output1 is an analog value equal to the magnitude of the input.

There is no parameters for this block.

43. STL:Statistical Function

This block gives the mean or median of incoming signals. There are four inputs

(maximum) can be connected to this block and it gives the mean or median of the inputs at

the output.

Input1 is an analog signal,one among the signals for which the mean or median of the


inputs has to be found.




inputs has to be foundd.



Output1 is an analog signal,which is the mean or median of the connected inputs.

Parameter 1(P01):Selection between mean(0) or median(1)..

44. LGM - Logarithm

ParametersP01:LOG/ANTI LOG selector P01=0-Log;P01=1-Anti Log

InputsA1:Analog inputs whose log og antilog is to be calculated.

OutputsY:Analog value equal to the log or antilog of the input.

This block computes the log or antilog of the input signal


45. RCL-Rate of Change Limitter

This block limits the rate of change of output irrespective of the fast variations in the input.

The maximum variation permitted in an execution cycle is limited by the parameter P01

specified. There are three inputs provided for this block.

Input 1,is a digital one, which is the enable/disable flag for the rate of change limiting

function. When the first input is 1,the output of the block will same as the second

input,which is the analog signal on which the limiting function is applied.

Input 2,is an analog one, which is the input signal on which the rate of change limiting

function is to be applied.

Input 3,is an analog one, which is an alternative to the parameter P01.ie.if this signal is

connected ,the rate of change limit will be equal to this input instead of the parameter P01.

Output, is an analog signal, which is the second input itself limited to the specified rate of

change limit.

Parameter (P01) limits for rate of change.


46. PLN - Polynomial Line Table For Linearisation

This block provides a look-up table which is mainly used for linearisation of signals from

non-linear transducers such as thermocouple , RTD etc. This provides 9 segment, piece

wise linearisation with ten co-ordinates. Compared to the FUNC block, the flexibility

available with the input co-ordinates makes the linearisation computation very easy. This

block can be used for split ranging of input and output signals, scaling of signals, low

cutting of flow signals, clipping etc.

Input 1, is an analog one, which is the input to be linearised or split.

Output 1 ,is an analog signal, which is the linearised signal.

Parameters:

P01 Input Value(X1)P02 Input Value(X2)P03 Input Value(X3)P04 Input Value(X4)P05 Input Value(X5)P06 Input Value(X6)P07 Input Value(X7)P08 Input Value(X8)P09 Input Value(X9)P10 Input Value(X10)P11 Output corresponding to X1P12 Output corresponding to X2P13 Output corresponding to X3P14 Output corresponding to X4P15 Output corresponding to X5P16 Output corresponding to X6


P17 Output corresponding to X7P18 Output corresponding to X8P19 Output corresponding to X9P20 Output corresponding to X10

47. CMP - Comparator

This block is an analog value comparator.It compares the analog inputs for 'greater

than,,'greater than or equalto','equalto','less than','less than or equal to' and 'not equal to'.

Input 1,is an analog input,which is compared with the second analog input or the second

parameter(P02).

Input 2,is an analog one,which is compared with the first input if connected.

Output 1,is a digital one,will be TRUE(1) or FALSE(0) depending upon the result

comparison.

Parameters:

P01

Logic code which decides the type of comparison.0-greater than1-greater than or equalto2-less than3-less than or equal to4-equal to5-not equal to

P02 Alternative for second input.ie if second input is not connected this parameter will be used for comparison

P03 Hysterisis constant for comparison


Annexure C

Modbus TCP

MODBUS® TCP/IP IS an Internet protocol. The fact that TCP/IP is the transport protocol of the

Internet automatically means that MODBUS® TCP/IP can be used over the Internet! Among other

things it was designed to reach this goal, and as part of this goal the MODBUS® protocol

specification has been submitted to the Internet Engineering Task Force (IETF). In practical terms,

this means that a MODBUS® TCP/IP device installed in Europe can be addressed over the

Internet from the USA from anywhere else in the world.

The implications for a vendor of equipment or an end-user are endless. Performing maintenance and repair on remote devices from the office using a PC and

browser reduce support costs and improve customer service.

Logging onto a plant's control system from home allows the maintenance engineer to

maximize his plant's uptime and reduce the number of times that he is called out from

home.

Managing geographically distributed systems becomes easy using commercially available

internet/intranet technologies.

MODBUS® TCP/IP has became an industry de facto standard because of its openness, simplicity,

low cost development, and minimum hardware required to support it.

At this moment there are more than 200 MODBUS® TCP/IP devices available in the market. It is

used to exchange information between devices, monitor and program them. It is also used to

manage distributed I/Os, being the preferred protocol by the manufacturers of this type of devices.

Combining a versatile, scaleable, and ubiquitous physical network (Ethernet) with a universal

networking standard (TCP/IP) and a vendor-neutral data representation (MODBUS® ) gives a

truly open, accessible network for exchange of process data.


The protocol - Modbus TCPModbus/TCP basically embeds a Modbus frame into a TCP frame in a simple manner. This is a

connection-oriented transaction which means every query expects a response.

This query/response technique fits well with the master/slave nature of Modbus, adding to the

deterministic advantage that Switched Ethernet offers industrial users. The use of OPEN Modbus

within the TCP frame provides a totally scaleable solution from ten nodes to ten thousand nodes

without the risk of compromise that other multicast techniques would give.

Performance from a MODBUS TCP/IP system

The performance basically depends on the network and the hardware. If you are running

MODBUS® TCP/IP over the Internet, you won't get better than typical Internet response times.

However, for communicating for debug and maintenance purposes, this may be perfectly adequate

and save you from having to catch a plane or go to site on a Sunday morning!

For a high-performance Intranet with high-speed Ethernet switches to guarantee performance, the

situation is completely different.

In theory MODBUS® TCP/IP carries data at up to 250/(250+70+70) or about 60% efficiency

when transferring registers in bulk, and since 10 Base T Ethernet carries about 1.25 Mbytes/sec

raw, the theoretical throughput is:

1.25M / 2 * 60% = 360000 registers per second and the 100 Base T speed is 10 x greater.

This assumes that you are using devices that can service Ethernet as fast as bandwidth is available.

Practical tests carried out by Schneider Automation using a MOMENTUMTM Ethernet PLC with

Ethernet I/O demonstrated that up to 4000 I/O bases could be scanned per second, each I/O base


having up to 16 12-bit analog I/O or 32 discrete I/O. Four bases could be updated in one

millisecond. While this is below the theoretical limit calculated above, it must be remembered that

the tested device was running with a lowly 80186 CPU running at 50Mhertz with an effective

computing power of 3 MIPS (compared to the 700 MIPS of a 500MHz Pentium). Also, these

results are nevertheless faster than the proprietary I/O scan methods used to date.

As low-end CPU's get cheaper, Momentum-type devices will chase the theoretical limit, although

they'll never reach it because the limit will be continually pushed further away with 1 Gigabit

Ethernet, 10 Gigabit Ethernet, etc. This is in contrast to other field-buses which are inherently

stuck at one speed.

How can existing MODBUS devices communicate over MODBUS TCP/IP?

MODBUS® TCP/IP is simply MODBUS® protocol with a TCP wrapper. It is therefore extremely

simple for existing MODBUS® devices to communicate over MODBUS® TCP/IP. To do this a

gateway device is required to convert MODBUS protocol to MODBUS TCP/IP.


DNP3

DNP3 (Distributed Network Protocol) is a set of communications protocols used between

components in process automation systems. Its main use is in utilities such as electric and water

companies. Usage in other industries is not common, although technically possible. Specifically, it

was developed to facilitate communications between various types of data acquisition and control

equipment. It plays a crucial role in SCADA systems, where it is used by SCADA Master Stations

(aka Control Centers), Remote Terminal Units (RTUs), and Intelligent Electronic Devices (IEDs).

It is used only for communications between a master station and RTUs or IEDs. ICCP(Inter-

Control Center Communications Protocol) the Inter-Control Centre Protocol, is used for inter-

master station communications.


http://en.wikipedia.org/wiki/ICCP

http://en.wiktionary.org/wiki/IED

http://en.wikipedia.org/wiki/Intelligent_electronic_device

http://en.wiktionary.org/wiki/RTU

http://en.wikipedia.org/wiki/Remote_Terminal_Unit

http://en.wikipedia.org/wiki/SCADA

http://en.wikipedia.org/wiki/Data_acquisition

http://en.wikipedia.org/wiki/Process_automation

http://en.wikipedia.org/wiki/Communications_protocol

http://en.wikipedia.org/wiki/Image:DNP-overview.png

Documents

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