Our client's DeviceNet network is cmposed of a CompactLogix PLC and a DeviceNet Scanner with 3 Danfoss VFDs. DeviceNet communication is only used for reading data from the VFDs. Problem arises whenever any of the VFDs are stopped. Fieldbus fault error appears on the VFDs and the corresponding DeviceNet nodes of the VFDs are not seen by the DeviceNet scanner. Any suggestions on how we can avoid this problem?

 

Hi,
I would suggest that you check the grounding of the newtork is done at only point.

other things i would suggest is to chekck the 60ohm resistors at the ends of the netwrok.
route the devicnet cable away from power cable of the drives and dont let the cable touch the drives.

some times harmonics may cause these kind of problems. chek the vfd panel grounding as well.