AB Ultra3000i error E27

Hi everyone, I'm looking for some help with a 5kW ultra3000i. I recently replaced a drive which was around 6 years old (version 1.16) and recieved a service exchange, version 1.52. Initially the drive worked fine but after an hour or so it faulted out with E27, "axis not homed", after homing it would continue to do this every 30/60 minutes. I was sent another service exchange unit (1.52) but this was the same, while waiting for the 2nd unit we had the 1.16 unit repaired, this has been fitted and is running fine.....?

Rockwell weren't sure why both units faulted out and said there was no reason why E27 should come on on this version and not the original ?

Any help or advice welcome

Kind Regards

CB

The E27 error occurs if you try to initiate an absolute motion profile and the axis has not been homed. I haven't seen this happen while a machine is running but we did have an issue where the E27 was popping up on a certain Ultra every time the main power was switched on. This particular servo had an incremental encoder so the axis had to be homed at every power-up. The PLC would set the home axis command and wait for the axis homed signal, then start the first motion profile. Well after much screwing around I discovered that the Ultra had a faulty output and the axis homed bit was flickering before the servo had actually been homed. Bad transistor maybe? Rather than repairing the drive I just put a timer on the corresponding PLC input to filter out the flickering.