ST600s | Err.29, what does this message mean, what can be done?

If the display of the frequency inverter shows the error message Err.29, it is a Profibus communication error.


  • There is no data transfer between the communication card and the host computer (or PLC).


  • After switching off the expansion card, insert it again and check whether the error still occurs the next time it is switched on.

If none of these error sources apply, please contact technical support.