Altivar drives on profibus network. Profibus master able to read data of drives but writing value to the CMD [Control word] in the sequence of 6, 7 & 15 according to CiA402/ Drivecom profile doesn't change drive state from Nst to Rdy. Drive is programmed for 3-wire control. Active command channel is Net [ Com. card]. What could be reason
When Altivar drives are programmed for 3-wire control, LI1 - logic input 1 is exclusively assigned as Enable input. This assignment can not be modified.
it is mandatory to make LI1 logic input ON before applying value 6,7 & 15 in sequence to CMD [Control word] rom profibus master while starting drive.
If LI1 is OFF, values 6,7 & 15 to CMD from Profibus master will have no effect.
So, make ensure that LI1 is ON before attempting to start drive with witting values 6,7 & 15 to CMD