Looks like this thread might be a bit stale, but I just implemented an Allen-Bradley network using their ethernet Point-I/O solution. Very slick architecture. The remote I/O network can be optionally setup as a redundant ring. The remote I/O blocks and ethernet adapters are very cost...
Thanks everyone for some really good suggestions. At this point, I am inclined to agree with Gunnar's and Ozmosis' assessments of the situation. The smaller Square D VFD's are not as robust in their EMI attributes as the larger unit, so RFI noise is probably the culprit.
Disconnecting the...
We have 3 Square D VFD's (10, 15, and 40 HP) on a CANOPN network connected to a PLC. Whenever we start the 10 or 15 HP motors, our CANOPN network drops out. The drives begin to start up then fail. The 50 HP VFD/motor does not exhibit this behavior.
If we disconnect the leads from the VFD to...