Mitsubishi Q Series Error

[EBLenny]

Hi all, new member here.

I have a problem with a mitsubishi q series plc (Q00UJCPU) which is used to control a filter cake press cycle.

Every now and then - usually 3-4 days apart, it will stop its process at the same position around 3/4 of the way through a cycle. The error code is always the same - "unit verify error" slot 3.

Now having exhausted all external fault finding, I changed the QY10 output card at slot 3 but yesterday the error came back with the same code.

According to the the software (GX-IEC 7.04), the only option left is to replace the entire PLC??

Would any members with more experience of the q series agree with this or is there another avenue of fault finding to pursue??


Thanks in advance.

 

[dploof23]

This is really just a shot in the dark, but it is possible the problem lies on the backplane. You could replace just the rack for much less $ than the entire PLC.

Just a thought.

Dave

 

[EBLenny]

Thanks for the reply Dave.

I have a base & psu on order anyway as the spares stock here is pretty dreadful, I haven't worked for this company long so am building things up as budget allows.

 

[EBLenny]

An update.

I replaced the whole Plc & backplane last night and it went through one cycle perfectly and without fault.

I've just come in to check on it this morning and the unit was in error again with the same code "unit verify error" slot 3.

I made sure the slot references match both on the Plc and the program file and they do.

I'm at a bit of a loss here now can anyone help at all.

Thanks.

 

[Badger]

http://www.accs.cz/Files/FA/PLC/Q_Hardware_Manual_EN.pdf

Use this link Go to 11.2.20 follow the steps. Hope it helps as I have not come across this before.

 

[Ronnie Sullivan]

Have you tried setting parameters in 'module verify error' to 'continue' rather than stop.

 

[nehpets]

This turns on special relay M9002 when the status of I/O module is different from entered status, when power is turned on. It remains on if normal status is restored. Reset is enabled only when special registers D9116 to D9123 are reset.

This relay remains "on" if normal status is restored. Therefore, to turn this "off", use the following method.

1)Method by user program Insert the circuit shown at below into the program and turn on the reset execution command contact to clear the special relay M.

| Reset execution order |
+----| |------- -[RST M9002]-+

| | |
Write special relay that will be reset

2)Perform forced reset by use of the test function of peripheral devices. For the operation procedure, refer to the manuals for peripheral devices.
3)By moving to the RESET position, the special relays are turned off.

This is taken from the GX Developer help files, it may help.

Steve

 

[dploof23]

You have probably already been here, but here is the troubleshooting methods for your error.

 

[EBLenny]

Thanks all for your input.

The fault now seems to have evolved slightly in that yesterday evening when I went to the presses to view status etc, the press had just stopped at a different part of the way through its cycle but the plc showed no error of any kind.

I manually operated the press to get it back to the stage it was at and set it off again and it ran for 20 minutes or so passed the stage it previously stopped at and just stopped again but with no error code at the plc.

I'm starting to think it may be a field device (input) that is slowly wearing out and causing voltage fluctuations that may be raising or lowering the card voltage outside of allowable tolerance causing outputs to switch off/cycle unintentionally.