We have a devicenet network that consist of a compact 1769-SDN, 20+ PoweFlex 40 drives, and a couple compact I/O blocks. Recently drives have been faulting randomly F71. This has not been an issue in the past. Drives fail occasionally and we swap them with a same HP drive. We use a him copycat to upload and download parameters.
The DeviceNet power supply is separated from other power and has been replaced recently to rule it out. The Network 120 ohm resistors are installed at the network’s beginning and end. The Network wiring has been inspected.
Has any experienced anything similar?
Thanks!