ACQ580 Randomly changes from AUTO to HAND during operation
I have an intermittent fault on an ACQ580 drive which is operated via a PLC. Under normal operation the drive is set to AUTO on the keypad allowing the PLC to operate the drive when required. However I am experiencing an intermittent fault where the keypad appears to be randomly forcing the drive from AUTO to HAND, this means that if the PLC has already started the drive when this random switch over occurs the PLC can't stop the drive. Or if it occurs while the drive is idle the PLC can't operate the drive. The fault is intermittent and the system can operate for several days without problems before it re-occurs. I'm currently looking at any parameter settings that could be the cause, comms faults between the drive and keypad, or a fault on the VSD itself. Any advice with regards to trouble shooting this issue would be appreciated.
Surely this is a very strange mistake to say the least, such a thing never happened to me.
If you are sure that nobody can change the status from the panel, try checking the setting of parameter 19.18 as it was programmed.
I recommend you consult the FW manual first to decide how to set this parameter.
Hope this help you
Source: ACQ580 FW MANUAL