Chain Steps Again

ABB PLC

There are 5 types of variables in the user program:
The chain steps: a chain step enables running sequential operations. Each chain step enables de definition of a step. One single step may be active at a time.

Anybody to explane this?

Regards

Hello isis;

As suggested in your original therad, this sounds like SFC/Grafcet transitions.
Look at the following link for details on the programming of sequential processes:
http://www.urswriter.com/SFCDraw/sfc_links.html

Hope this helps,
Daniel Chartier