Hello

I have a problem with a Siemens 840D NCU573.5 plc 

I get the folowing error on PLC and cant figure out what is the problem.

The PLC stays in stop mode!

Hello,

Since this issue is related to NCU you should have open this topic inSINUMERIK CNC automation systemsproduct conference.

Now to your topic, the significance of attached snap is PLC is in STOP mode due to alarm 400110. Since the language in attached snap is not English, could not help you. Please attach the snap shot of alarm/fault displayed on OP & seven segment LED status of NCU.

Hope this helps.