I have a Simatic Project with a S7-1500 CPU and several CU240 E-2 PN used to control the speed of several fans. The speed reference is transfered via Profinet using the Telegram #20.

Currently i don't have any problem with this.

But the client has asked us something:

If the drives lose the Profinet comunication with the PLC they must not go to stop, they must keep running at the last good speed reference before the fault (or at least to a prefixed speed reference).

What they really do not want is the fans to stop.

Could anyone tell me if this is posible and (if it is) which parameters should i look into.

Thank you.

Hello Jaime:

See if the following FAQ provides the information you require:

Micromaster MM4, Sinamics G220: loss of setpoint, wire breakage

https://support.industry.siemens.com/cs/us/en/view/67653743

The document addresses the case of an analog setpoint, you may be able to adapt it to a Profinet setpoint.

Hope this helps,

Daniel Chartier 

Hello Daniel.

It don't help this information

Miquel