Hello,

I am commissioning new equipment utilizing S120 Booksize system. I have 4 CU320-2PN control units distributed among the drives. 3 work just fine, but I am having problems with one. After running for say maybe 10 minutes the control unit becomes completely unresponsive. RDY LED is solid red, COM is solid green, BOP does not show any errors. The control unit becomes unresponsive to ping and can not go online with starter, and the BOP buttons do not do anything. Removing and reinstalling the BOP causes the BOP to not turn on at all. This particular Control Unit is in the middle of a profinet daisy chain, 1 control unit before and two after - the other control units still communicate and work fine.

The control unit in question is v 5.2.3. System utilization (p9976[0]) is 72.85%. The control unit operates 3 double motor modules, 6 motors in total, all six extended setpoint channel feature enabled, closed loop speed control.

Power cycle allows the control unit to communicate again and BOP is operational, and drives/motors run as expected until issue happens again.

Since I am not able to see the fault through starter or through the BOP I am at a loss as to how to proceed troubleshooting.

Hi,

you can lock on this post

CU 320-2 hanged after 6 min of all three servo motor enabled