s7-graph sequences

[abdel89]

Hi dear programmers,

Im a newbie in plc programming, i start using s7-graph to program a palletizer i wrote a typical program but im facing a little problem :

I wanted to use the OFF_SQ input from the called block wich is generated by s7-graph compiler, i used it to stop the sequence once the emergency button or the stop PB are pushed but it seems that once the OFF_SQ input is active the whole seuences are desactivated and if i wanna go back to the normal executing i have to INITIALIZE the graph with the INIT input.

I wish i could go back to the step wich at it the EM or STOP PB were pushed so the sequences could continues normally.

If its not possible pls advice the best way to do this and what is the better method of writing sequential programs if s7-graph not highly recommanded.

Best regards,

Abderahim

 

[TurpoUrpo]

Just put it on man.

 

[abdel89]

U mean instead of triggring the OFF_SQ input when EM or STOP-PB are pressed i should trigger the MAN input. Is that what u mean ? And this will let the graph just wait for the operator signal to reactivate again the process?


Thanks for the answer .

And by the way what are tips to do sequential programs in STL?

 

[TurpoUrpo]

For stl sequencers use JL instruction, its much like CASE in SCL.

For graph you can also use halt_sq input to halt sequencer according to help.

I have just put them to man as i never use outputs inside graph block, so i can interlock outputs elsewhere. Naturally we do remove energy from system in case of e-stop.