help regarding programming

[aakash 0]

hi i was checking program there a certain bit (q4.2) is getting ON but i cant locate the way how that bit is getting activate i tried searching in program .PLEASE tell me what can i do to check that

 

Regards  

Aakash

[Bryll 31]

If you are using Step 7 Classic, locate the tag and select it, then press "ctrl"+"alt"+"Q".

Then you can see where in the program the tag is used for reading and/or writing.

 

In TIA Portal, locate and select the tag, press "shift"+"F11".

The cross-ref. for the tag will pop up and show you where the tag is used for read and/or write access.