I am attempting to utilize a AB 1771-SDN scanner in a PLC 5 to read a DeviceNet encoder count and consistently start and stop a VFD via DeviceNet. The VFD basically drives the encoder shaft. I want start the VFD until X counts are reached stop the VFD reset encoder, start VFD until X counts reached stop VFD reset encoder etc. etc. Encoder is reset using explicit msg via Block xfer. VFD start/stop done via DeviceNet as well. Encoder always reaches count "setpoint" but overrun is inconsistent. Expected some overrun but thought it would at least be consistent. Not a high speed app. Any thoughts would be greatly appreciated. AB's answer was to hardwire start/stop to VFD.