A hitch with 1395 drive

Hi guys,
I am facing a peculiar problem a 1395 dc drive, make- alllen bradely.
When I issue a jog command to the drive via PLC it works fine , but when I impart a run reference to the drive it fails to produce any output.The drive receives the reference from the PLC but fails to produce an output voltage inspite of the fact that its output contactor is energized.
What could be the cause?

pls help guys!!
take care

Does the panel indicate that all the permissives are made?

yes ,all the permissives are made. The plc issues the run command to the drive along with the speed reference , but no output voltage is recorded.

I had an issue similar to this with a 1395 a while ago, it eventually stopped altogether (every time we would get to the machine it would jog then start back up and run for a few hours). The problem ended up being a relay that was going and finally just failed completely. I don't remember if it was internal to the drive or external but I would start there.