PowerFlex 70

[Gordo26 0]

I had a strange occurrence today where my PowerFlex 70 drive just stopped. It had no faults, it just said Stopped, all I had to do was press the green start button to get it going again but this has never happened before. I did have a DeviceNet error just before this happened. I use DeviceNet inputs into the drive for start/stop/direction. Any suggestions on what the cause could be would be greatly appreciated. Thanks, Gordo26

[Ken Roach 194]

If you have the DPI Fault parameter set to "Stop", and the DeviceNet is interrupted or disconnected, the drive will stop but not fault. Start commands are False -> True transitions on networked A-B drives, so the drive won't start back up without another False -> True transition of the Start bit.

[Gordo26 0]

My apology, I'm not using a DeviceNet communication module on the drive itself, I am using digital inputs to the drive that come from a remote output deviceNet card. I checked my deviceNet error and it does not come from the output card that I'm using to control my drive so I don't think the deviceNet error is the problem. Thanks for your suggestion though, much appreciated! Thanks, Gordo26

[Joe E. 259]

Is there a separate output on the DNET card for "Stop"? Often, the "STOP" signal must be held high (ON) for the drive to run. Some output devices turn off all outputs when they lose comms. Some can be configured to hold "last state". In this case, with what's given, I suspect the DNET card turns off its outputs when it loses comms, dropping the "STOP" command to the drive, which causes the drive to stop as if you had hit the "stop" button. When you hit the "Start" button later, the comms are OK, so the "STOP" command is on.