IEC Basics. Presented by. Bill Lydon, Director PLCopen North America Automation Industry Consultant

Transcription

1 IEC Basics Presented by Bill Lydon, Director PLCopen North America Automation Industry Consultant Page 1

2 Why standard software? Standardization Improves Productivity Quality & Reliability Page 2

3 Percentage of Software development costs in production systems (source: McKinsey) 100% 80% 60% 40% 20% 0% Mechanic Electric Software Page 3

4 Software Functions Increasing Complexity Increases Exponentially Page 4

5 the never ending story of software enhancements.. new requirements... new functionalities. new wishes... Typically software enhancements & maintenance cost are 2 times the initial development investment. Page 5

6 Standard Software Advantages Conceptual Design Maintenance Specification Commissioning Functional Design Refining Testing Coding Verification Page 6

7 Standard Software Advantages Improved Software Reliability Common Design Architecture Improved Productivity Common Base of Understanding & Training Improves Maintenance Efficiency Emergency Bug Fixes & Corrective Bug Fixes Adding Features & Functions Mandatory Changes ( Law, Safety,...) Enhancements Studies show software maintainers spend about 50% their time understanding the code. Lifecycle Maintenance = 2 X Initial Development Page 7

8 What is IEC ? IEC International Electrotechnical Commission (IEC) Open Programmable Logic Controller Standard 1st published rd edition published 2013 Defined application program development environment Strong data typing for error prevention 1 Structuring Tool Sequential Function Chart (SFC) 4 programming languages: 2 Textual & 2 Graphical Program Organization - Program Structuring & Reuse Page 8

9 IEC Strong Data Types BOOLEAN REAL INTEGER STRING TIME ARRAY STRUCTURES USER DEFINED Page 9

10 Languages Instruction List (IL) Structured Text (ST) Ladder Logic/Diagram (LD) Function Block (FB) Sequential Function Chart (SFC) Page 10

11 Ladder Diagram (LD) Standardized set of relay ladder programming symbols and terminology Electrical Flow Large base of users Boolean equations Function Blocks Easy rules A B C - -- / ( )---[Function[--- Page 11

12 Ladder Diagram (LD) Page 12

13 Instruction List (IL) Single statements, or instructions, written and executed in a line-by-line format. Single accumulator based execution model Low Level Programming One operation such as storing a value in the accumulator register, is allowed per line LD A AND B ST C Page 13

14 Instruction List (IL) Page 14

15 Structured Text (ST) High level language, block structured Syntax resembles PASCAL, C, C+ Complex statements and nested instructions possible Support for Iteration loops (REPEAT-UNTIL; WHILE-DO) Conditional execution (IF-THEN-ELSE; CASE) Functions (SQURT(); SIN()) C:= A AND NOT B If A = FALSE THEN... CASE Select OF... Page 15

16 Structured Text (ST) Page 16

17 Function Block Diagram (FB) Graphical Language Program elements appear as blocks to be wired together A B AND C Function Examples: ADD, SQRT, SIN, COS, AND, OR, CASE, etc. Page 17

18 Function Block Diagram (FB) Page 18

19 Function Block Self Contained Building Blocks Inputs Function Block Explicit Data Variables Tag Names Logic Actions/Calculations Outputs Inherent Data Integrity Checks Page 19

20 Function Block Self Contained Building Blocks Function Examples AND, OR, XOR, GATE Inputs PID, SELECT, LIMIT SQUARE ROOT, COS ADD, SUB, DIV, MUL Outputs Page 20

21 Function Block Self Contained Building Blocks Inputs Send/Receive Serve UP WEB Pages Send Messages (SMS) Send SOAP Messages Send XML Messages OPC UA Communication PEER to PEER Outputs Page 21

22 Function Block Encapsulation BUILD YOUR OWN FUNCTIONS Page 22

23 Function Block Encapsulation Inputs User Created Object Outputs Built from standard blocks... Page 23

24 Function Block Ladder Logic Instruction List Structured Text Inputs Build your own function blocks with Ladder Logic, Instruction List, or Structured Text Your Own Function Block Outputs Standardization Reuse Tested Code Easily Understood Self Documenting Password Protect Page 24

25 Sequential Function Chart (SFC) Sequential Controls Procedural Controls Structured Describes Process Logic Driven Partition Control Functions Rapid Visual Diagnostics Step 1 Transition Step 2 Transition Action 1 Action 2 Action 1 Page 25

26 Sequential Function Chart (SFC) Serial & Parallel Processes Process Synchronization Application examples Startup Sequences Shutdown Sequences Presses Productions Lines Process Automation Packaging technology Machine tools Batch Process Control S88 Flexible Manufacturing Page 26

27 IDE - Integrated Design Environment (IDE) Multiple Automation and Control Disciplines Process Design Logic Simulation Automatic Documentation Engineering Tools Online Debug Environment Breakpoints Watch Windows Strip chart Recorder Integrated HMI IEC Controller Page 27

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29 PLCopen Extensions Vendor Independent, Not for Profit Organization Extends IEC Functionality Page 29

30 More Information... Electronic Newsletter Application Examples Specifications Compliant Products Bill Lydon, Director PLCopen North America Automation Industry Consultant Page 30

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