1. Overview PLCopen - IEC 61131 - 3
“There are three classes of people: those who see. Those who see when they are shown.
Those who do not see.”
 Leonardo da Vinci (Italian draftsman, Painter, Sculptor, Architect and Engineer whose genius epitomized the Renaissance humanist ideal )
"Any sufficiently advanced technology is indistinguishable from magic.“
Arthur Charles Clarke 1

2. IEC = International Electro-technical Commission
The goal of this presentation is to provide the attendees with information and a review of the IEC control system automation software standard which is an open (non-propriety) based standard applicable to the implementation of a PLC Open system including the application of Field Bus technology. The attendees will gain knowledge involving the IEC software standard utilizing RTU/PLC/DCS.
IEC = International Electro-technical Commission
A World organization that prepares and publishes international standards for all electrical and electronic related technologies
Founded in 1906 * Over 50 participating countries * Different levels of membership

3. What is the IEC 61131 standard ?
IEC is an international standard for programmable controllers consisting of 5 parts:
Part 1: General information
Part 2: Equipment characteristics
Part 3: Programming languages
Part 4: User guidelines
Part 5: Communication

4. IEC 61131 and PLC Open – Mission
PLC Open is a vendor and product independent world-wide organization that brings greater value to users of Industrial Control Systems through the pursuit of the IEC software development standard

5. Goals of IEC 61131.3 and PLC Open
PLC Open Certification and compliance testing
Definition of several levels of IEC compliance (Base Level, Portability Level, Full compliance Level)
Establish strict test procedures
Establish certification tests at independent test institutes
Ultimate Goal: Portability of PLC programs
Program once run on any hardware platform
not hardware specific or dependent

6. Table of contents Advantages of IEC61131-3 for programmers
History and international standards 1970 to 1995
7 parts of the IEC standard
IEC software models
the 5 languages of the IEC
FBs (Function blocks) and POUs (Programmable Organizational Units)
IEC data types, standard functions and standard function blocks
PLCopen certification

7. Table of contents - continued
PLCopen compliance levels
PLCopen training logo
PLCopen address
"Concern for man himself and his fate must always form the chief interest of all technical endeavors, concern for the great unsolved problems of the organization of labor and the distribution of goods--in order that the creations of our mind shall be a blessing and not a curse to mankind.
Never forget this in the midst of your diagrams and equations." Albert Einstein

8. Advantages of IEC 61131-3 International accepted standard
Step by step all suppliers will support it
Uniform structures, languages, and the way of handling
It saves you time
Unique software model and data/ type concept
You only have to learn it once for different controller types
Reduced misunderstandings and errors
Standard functions and function blocks
Reusability of tested software 3

9. Advantages of IEC 61131-3 Supports safety and quality programming
Easy and comfortable structuring
Data typing prohibits programming errors
Provides the best language for each problem
Consistent specifications of 5 languages
Two textual and two graphical languages
One structuring language, providing an overview
Availability of high level language
Possibility to mix different languages 4

10. International Language Standardization
NEMA Programmable Controllers Committee formed (USA)
GRAFCET (France)
DIN 40719, Function Charts (Germany)
NEMA ICS-3-304, Programmable Controllers (USA)
IEC SC65A/WG6 formed
DIN , Programmable Controller (Germany)
IEC 65A(Sec)38, Programmable Controllers
MIL-STD-1815 Ada (USA)
IEC SC65A(Sec)49, PC Languages
IEC SC65A(Sec)67
IEC 848, Function Charts
IEC 64A(Sec)90
IEC
Type 3 report recommendation
IEC
name change 70 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96
Source: Dr. J. Christensen 5

11. The 7 Parts of The IEC 61131 Standard
Part 1 General overview, definitions IS
Part 2 Hardware IS
Part 3 Programming Languages IS
Part 4 User Guidelines IS
Part 5 Communication IS
Part 7 Fuzzy Logic IS
Part 8 Technical Report
IS = International Standard 6

12. IEC 61131 - Part 1 - General Overview
Definitions and glossary of terms used in the standard
List of related / referenced IEC standards
Principal functional characteristics of programmable controller systems 7

13. IEC Part 2 - Hardware
Electrical, mechanical and functional requirements for Programmable Controllers and associated peripherals
Service, storage and transportation conditions
Information to be supplied by manufacturer
Test methods and procedures for verification of compliance of programmable controllers and associated peripherals 8

14. IEC 61131 - Part 3 - Programming Languages
Software-, communication- and programming-model
Definition of five interlinked programming languages
Syntax and semantics of two textual and two graphical languages: Instruction List (IL), Structured Text (ST), Ladder Diagram (LD) and Function Block Diagram (FBD)
Sequential Function Chart (SFC) for program structuring 9

15. IEC 61131 - Part 4 User Guidelines
Assists the user in:
Utilizing the other parts of the programmable controller standard
Specifying the requirements for applications
Selecting and implementing systems 10

16. IEC 61131 - Part 5 Communication
Based on MMS (Manufacturing Message Specifications) (still in progress) 11

17. IEC Part 7 Fuzzy Logic
Provides the definition of fuzzy control sets 11

18. IEC 61131 - Part 8 Technical Report
Provides guidelines for the application and implementation of programming languages for programmable controller 11

19. IEC 61131-3 Software Model Configuration A
Resource L
Resource L
Task1
Task2
Task3
Task4
Program P1
Program P2
Program P3
Program P4
FB1
FB2
FB3
FB4
global and direct addressed variables
access paths
Task association
Access path association 12

20. OB - Organization Block FC - Function FB - Function Block
Operating System
OB1 FC FB
Other
OBs
OB - Organization Block
FC - Function
FB - Function Block
Memory

21. Definition of Software Model Terms
Configuration
A language element corresponding to a programmable controller system
Resource
A language element corresponding to a signal processing function and its human-machine interface and sensor actuator functions, like a CPU in your system
Task
An execution control element providing for periodic or triggered execution of a group of associated program organization units
Program
Highest level program organization unit, several in - and outputs possible, can call FBs and Functions FB
Program organization unit Function Block, several in - and outputs possible, can call other FBs and Functions 13

22. IEC 61131-3: The Common Elements•
Character set (English )
Data types (BOOL, WORD, INTEGER )
Variables (VAR, VAR_input, VAR_output )
POUs,
Program Organisation Units (Function, Function Block...)
SFC Elements (Steps, Transitions )
Configuration elements :
(Tasks)
Basis for software re-use

23. IEC 61131-3 Elementary Data Types
No Keyword Data Type Bits 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
BOOL
SINT
INT
DINT
LINT
USINT
UINT
UDINT
ULINT
REAL
LREAL
TIME
DATE
TIME_OF_DAY
or TOD
DATE_AND_TIME
or DT
STRING
BYTE
WORD
DWORD
LWORD
Boolean
Short integer
Integer
Double integer
Long integer
Unsigned short integer
Unsigned integer
Unsigned double integer
Unsigned long integer
Real numbers
Long reals
Duration
Date (only)
Time of day (only)
Date and time of day
Character string
Bit string of length 8
Bit string of length 16
Bit string of length 32
Bit string of length 64 32 64
IEC Elementary Data Types

24. Directly represented variables – Hardware Addressable Inputs and Outputs The identifier of a directly represented variable always begins with "%" character. Below are the naming conventions of a directly represented variable for a channel of a single board. "s" is the slot number of the board. "c" is the number of the channel. %IXs.c free channel of a Boolean input %IDs.c free channel of an integer input %ISs.c free channel of a message input %QXs.c free channel of a Boolean output %QDs.c free channel of an integer output %QSs.c free channel of a message output Below are the naming conventions of a directly represented variable for a channel of a complex equipment. "s" is the slot number of the equipment. "b" is the index of the single board within the complex equipment. "c" is the number of the channel. %IXs.b.c free channel of a Boolean input %IDs.b.c free channel of an integer input %ISs.b.c free channel of a message input %QXs.b.c free channel of a Boolean output %QDs.b.c free channel of an integer output %QSs.b.c free channel of a message output Below are examples: %QX1.6 is the 6th channel of the board #1 (Boolean output) %ID2.1.7 is the 7th channel of the board #1 in the equipment #2 (integer input)

25. The 5 Languages of IEC
Instruction List Structured Text Sequential Function Chart
LD A
ANDN B
ST C
C:= A AND NOT B
Step N FILL
Step 3
Step S Empty
Transition 1
Transition 2
Function Block Diagram Ladder Diagram
A B C
-| |--|/| ( )
AND
A C B 15

26. Ladder Diagram (LD)
Standardized, rationalized set of relay ladder programming symbols
Based on well-known US-style of programming, resembling electrical drawing standard
A B C
-| |--|/| ( ) 16

27. -| |--|/|----------------( )
Ladder Diagram (LD)
Ladder Diagram (LD) is a graphic representation of Boolean equations, combining contacts (input arguments) with coils (output results). The LD language enables the description of tests and modifications of Boolean data by placing graphic symbols into the program chart. LD graphic symbols are organized within the chart exactly as an electric contact diagram. LD diagrams are connected on the left side and on the right side to vertical power rails.
A and not B equals C
-| |--|/| ( )

28. Instruction List (IL) Single Accumulator based execution model
Based upon the German ‘Anweisungsliste’, AWL
Only one operation such as storing a value in the accumulator register, is allowed per line
LD A
ANDN B
ST C 17

29. Instruction List (IL)
Instruction List, or IL is a low level language. It is highly effective for smaller applications or for optimizing parts of an application. Instructions always relate to the current result (or IL register).
The processor indicates the operation that must be made between the current value and the operand. The result of the operation is stored again in the current result.
LD IX1 (* push button *)
ANDN MX5 (* command is not forbidden *)
ST QX2 (* start motor *)

30. Structured Text (ST) High level language, block structured
Syntax resembles PASCAL
Complex statements and nested instructions possible
Support for
Iteration loops (REPEAT-UNTIL; WHILE-DO)
Conditional execution (IF-THEN-ELSE; CASE)
Functions (SQRT(), SIN())
C:= A AND NOT B 18

31. High level language, Syntaxed structured
Syntax resembles traditional programming code
such as C++, JAVA, PASCAL
Complex statements and nested instructions possible
Support for
Iteration loops (REPEAT-UNTIL; WHILE-DO)
Conditional execution (IF-THEN-ELSE; CASE)
Advanced Math Functions (SQRT(), SIN())
C:= A AND NOT B
Applications with complex calculations and data processing examples would involve two phase flow calculations, gas calculations, etc.

32. Function Block Diagram (FBD)
Graphical language, widely used in Europe
Allows program elements which appear as blocks to be "wired" together in a form analogous to a circuit diagram
Used in many applications that involve the flow of information or data between control components
AND
A C B 19

33. Most applications apply to analog control
Graphical language, widely used in Distributed Control Systems (DCS) and Analog intensive control systems
Allows program elements which appear as blocks (Function Blocks) to be connected together in a form analogous to a circuit diagram
Most applications apply to analog control
Used in many applications that involve the flow of information or data between control component
Examples include PID and analog scaling
AND
A C B

34. Sequential Function Chart (SFC)
Graphical language which provides a diagrammatic representation of program sequences --> flowchart
Based on the French Grafcet (IEC 848)
Main structure and suitable for rapid diagnostics
The basic elements are steps with action blocks and transitions
Steps consist of a piece of program that is carried out until a condition specified in the transition is met
Programming of complex tasks by dividing in smaller parts
Each element can be programmed in any of the IEC- languages such as LD or ST or IL or FB mix or match any of the languages
Step N FILL
Step 3
Step S Empty
Transition 1
Transition 2 20

35. Step 1 Transition Step 2 Action 1 Action 2
Technological programming language for describing Sequential Controls
Structured program draft
Description of the process with steps
and transitions
Clear, easy to understand by the process, production and operations staff
Application examples
Presses and Packaging technology
Production lines
Process technology (start up – shutdown)
OEM equipment machinery technology
Rotating Machinery e.g. compressors, pumps
Step 1
Transition
Step 2
Action 1
Action 2

36. POU = Program Organization Unit
POU’s enable re-use of software from macro level (Programs)
to micro level (FB and Functions).
A POU consists of a header (variable declaration) and the
body (instructions). 22

37. IEC 61131-3 Standard Datatypes
Bit string types (BOOL, BYTE, WORD, DWORD, LWORD)
Integer types (SINT, INT, DINT, LINT)
Unsigned integer types (USINT, UINT, UDINT, ULINT)
Real types (REAL, LREAL)
Time types (TIME, DATE, TIME_OF_DAY, DATE_AND_TIME)
Character types (STRING)
Vendor and user defined data types are possible
Direct derived, sub range, enumeration
Array, structure 23

38. IEC 61131-3 Standard Functions
Bit string functions (AND, OR, XOR, NOT, SHL, SHR, ROL, ROR)
Numerical functions (ADD, SUB, MUL, DIV, MOD, EXPT, ABS, SQRT, LN, LOG, EXP, SIN, COS, TAN, ASIN, ACOS, ATAN)
Type conversions (e.g. USINT_TO_DINT, BOOL_TO_BYTE)
Selection functions (SEL, MIN, MAX, LIMIT, MUX)
Comparison functions (GT, GE, EQ, LT, LE, NE)
String functions (LEN, LEFT, RIGHT, MID, CONCAT, INSERT, DELETE, REPLACE, FIND)
Vendor and user defined functions are possible 24

39. IEC 61131-3 Standard Function Blocks
Bitable (SR, RS, SEMA)
Edge detection (R_TRIG, F_TRIG)
Counters (CTU, CTD, CTUD)
Timers (TP, TON, TOF, RTC)
Vendor and user defined function blocks are possible 25

40. PLCopen
Mission
We want to be the leading association resolving topics related to control programming to support the use of international standards in this field. 26

41. PLCopen PLCopen was founded on June 15, 1992 in Giessen, Germany.
Target was to promote IEC , inform customers and give
more weight to the IEC standard.
PLCopen
Standardization in Industrial Control programming
TC6

42. The Essence of Compliance without testing there is no standard
The IEC standard gives rules for compliancy
Certification gives guidance for users towards real IEC programming systems (e.g. PLCopen certified list shows compliant products) 27

43. PLCopen Compliance Level
To take away the confusion, PLCopen....
.... has defined 2 levels of compliance with a defined set of features
.... has defined an accreditation procedure
.... has accredited test institutes
.... developed test software, shared amongst members
.... has defined a certification procedure
.... and has members with certified products
This assures compliance now, and in the future. 28

44. PLCopen Compliance Levels
Application Program FB
Variable
Code Body
Conformity Level &
Reusability Level
Re-usability of Function (Block) libraries
Base Level
Portability of minimal systems 29

45. Compliance
Certified products
can use these logo’s 30

46. PLCopen Training Logo 31

47. www.plcopen.org PLCopen P.O. Box 2015 NL 5300 CA Zaltbommel
The Netherlands
Tel:
Fax: 31