PLC Prog. Languages Validation

M

Thread Starter

Marcos Assumpcao

IEC 1131-3 defines some types of languages for programming a PLC, that is, Ladder, Sequential Function Chart, Function Block Diagram, Structured Text and Instruction List. I would like to know, for the same application, which one of the types above it is easier to be validated. Is there a methodology for validating PLC programming languages?

Marcos Assumpcao
 
P
Marcos,

The different languages exist to service different applications, for eaxmple; an application may be easy to code in structured text, but devilishy hard (impossible) to code using function block.

Having said that - the easiest language to validate (I'm assuming you mean verify prior to compile) is either instruction list or ladder - both can be expressed in a very similar format to the orginal assembly code.

Cheers.
 
J
For regulatory type of process control function block diagram are easiest to validate, for logic and sequence it may be something else.

Function blocks are easy to validate for process control because all the complex PID algorithms etc. are encapsulated in blocks already validated by the manufacturer. All you need to do is to validate the links and the parameter settings.

Jonas Berge
==================
[email protected]
www.smar.com
 
M

Marco A. Rodriguez, P.E.

Personally, I find ladder logic the easiest to validate. The animation tools provided by the manufacturers make troubleshooting much more easier. SFC are also easy to troubleshoot SFC are better for batch and sequential control while ladder is more frequently applied in discrete manufacturing.
 
Top