Omni Flow Computer to AB KE serial comms


Thread Starter

Joel Weder

We've been working for some time trying to find the source of a problem with an Omni Flow Computer. It is being polled by a PLC 5/11 serially through a KE card, 9600, 8N1, BCC, Full Duplex. We find that on seemingly random occasions the Omni's serial port locks up and will not reply to the DF1 MSG's being sent.

The last time we noticed the problem occurring, the Omni's display flipped to the page showing software and hardware installed. Looked like it had perhaps tried to reboot itself? The Omni tech connected on to the port with his laptop then switched it to Modbus and tried talking to it. No go. Some time later it started talking again, apparently shortly after being switched back to RS232 mode. The only hardware issue we've noticed is that the Omni serial port's common is not at chassis ground, while the KE card's is.

Anybody out there doing Omni-KE serial comms who has any experience to share?