Robo

Well have fixed this issue. Mitsubishi supplied another CPU but this was 3 years old. Didn't work either and had the same errors. After more discussions, Mitsubishi agreed to supply the latest CPU (Q04UDH). I converted the program as before and the download worked OK. No errors anymore. Thanks to those that responded.

Thanks for your reply. Appreciate it. The PLC is not local so I am unable to access as I would like. Your suggestion was to be my "last resort" if we can't get to the bottom of this. We are currently waiting for the local Mitsubishi support (if there is such a thing) to get back to us. Will post the "fix" when I know.

Thanks Gambit for your reply. Have attached a file with all in case I missed anything you need. Did find some other CPU requirement but not sure it is relevant.   PLC configuration.pdf

Well a newer CPU didn't work. Network settings are 'normal' and should work according to the book? Q04UDHCPU is universal and should work according to the book? Does anyone have any further ideas? I think that the * (point) under the IP address is only for built in ethernet ports.

Thanks Guys for the response. I'm currently looking into both options. I'll post the outcome so we can all learn from this. Can't believe they sold me a "new" CPU that could be 8 years old?

Thanks Gambit, the CPU was just purchased in April 2017. I didn't consider the version as I assumed it would be the latest. I am unable to physically check this at the moment but have attached the box it came in. From this can I assume the manufactured date is 14th June 2009? If so, I imagine that this age may be the problem?

Needed to upgrade my CPU to a bigger memory. Have chosen the Q04UDH to replace the Q03UD. Ran the 'Project...Change PLC Type... and also changed the PLC CPU parameter. Compilation reported no errors. However, when downloading the attached error comes up? The PLC layout includes CPU, Ethernet Card, CCIE field Master Card, various DI/O and analog. All other settings have not changed. Does anyone have any ideas where to look next? This should be straight forward exercise.    

No. Using start/stop does not re-initialise the PID. It just turns off the PID function leaving the autoMV where it was prior to the stop function. So the next time you use the PID function it resumes at a point you stopped last time. This causes a major malfunction with our process.  I've just had a colleague tell me that the auto/manual selection bit can be used to move the manMV (writeable) into the autoMV(read only), so by toggling the auto/manual and writing '0' to the manMV should do the trick.

Q03UD GXWorks2 Version 1.499V

Does anyone know how to reinitialise the PID function on 1 loop only. I am using 3 loops and don't want to use the PIDINIT command as this will perform an initialise on all loops while they are running OK. I am using the PIDRUN/PIDSTOP commands for loop 3 and this is causing the next PID process to use the "old auto mv" it had stored prior to the PIDSTOP command for the 2nd and subsequent processes. All loops run in auto only. I have used PIDPRMW but this doesn't work.

Thanks again kaare_t. The process is a chemical exothermic reaction and we have only 1 shot at it because the cycle time is too short. We also cannot have any major overshoot as it can start a thermal runaway reaction. In essence we can only make small changes to the PID, start the process, log the results and repeat for the next cycle. Very long winded and costly. No option to autotune either even if we had an autotune feature. I managed to get the P & I set manually to a figure that has resulted in minor oscillation but not what is needed as a completed process. I will followup on your advice as I believe this is the only option open to me.

Thank kaare_t   Is there any info on manually tuning the PID loop or getting software to calculate the PID parameters once we have all the log files graphed to show response etc?

Thanks, this worked.

Thanks Kaare_t,   Have already tried that but my PLC comes up with " Local device file does not exist in connected PLC" I have the latest serial number PLC supported?

Can anyone tell me how to upload from the PLC a selection of eg D areas 0-1000, and save to a file (*.csv?) for future reference as commissioning files. Have tried 'Online-Monitor-Device/Buffer Memory Batch but doesn't seem to work?