PLCs are very powerful hardware systems for controlling various classes of control systems. would like to search for validation and checks that can be applied on the PLC program to capture the errors and get a user agreement before producing the code and relying only on tests or animation.

I would like to share some issues that may be applied before constructing the ladder diagram to ensure the ladder diagram will be user-agreed, consistent, complete, and reachable from the control point of view.

would like also to discuss possiblities to automatically generate PLC block diagrams. hence, there will be a need for a language (textual form) to represent the PLC diagrams.

would like to map some of my work on control system dealing with developing software controllers towards PLC, but waiting for answers about this two issues:

1 - available validation, consistency, completence checks for PLC?
2 - existence of textual represntation for PLC.

kind regards
islam

 

Look at http://www.plcorg.com IEC 1131 part 3 standard that specifies also textual PLC programming languages.

In my opinion, for the moment, PLC programming languages implemented by PLC manufacturers are very specific to their hardware. Two ladder diagrams constructed for different PLCs (sometimes even from the same manufacturer) can not be interchanged.

cghaba

 

I believe that the link provided should have read plcopen.org

Cheers from: Jeremy Pollard, CET The Crazy Canuckian!
Integration and Automation Training, Consulting, and Software
http://www.tsuonline.com