Hi all,

I am trying to control some stepper motors with motor drivers/PTO signal using a Siemens S7-1200 PLC. When I move the axis by enabling it with MC_Power, then MC_MoveRelative I can make it move the way I want, say 45 degrees. If I reuse the function MC_MoveRelative the motor doesn't move however. In other words, if I enable the axis, then put MC_MoveRelative in OB1 I would expect the motor to keep turning with 45 degree increments, but it only moves once.

Do I need to reset a variable? I want to be able to use MC functions with the same datablock multiple times in my program, how can I accomplish this? Does somebody have an example of a PLC program (TIA v14) that control a stepper motor?

Many thanks,

Bnurps

What do you mean by "reuse MC_MoveRelative"? Do you call the same instance of it once again? Show the code as "a line of code is worth thousand words".

Hello,

check your programming and  the error ID.

11.1.6.2 MC_MoveRelative: Funktionsdiagramm V3

https://support.industry.siemens.com/cs/ww/en/view/109739589