Mitsubishi PLC

[MS10]

Hi everyone, I am new to Mitsubishi PLC and having a bit of difficulties with the device memory. I am currently modifying a previous project written by my colleague. There are some values previously saved in the device memory and I have downloaded these to the PLC. The problem that I'm facing is, I can't seem to write a value to these device (for e.g. from the HMI). I am pretty sure it is due to the device memory that I have downloaded but I can't seem to erase this values either. I have tried using 'clear PLC memory' and 'format PLC memory' and monitor them at the same time. The devices values went to 0 after clearing (PLC is in STOP mode because I can't clear the memory when it is in RUN mode). Once I switch the PLC to RUN mode, the previous values came back. I have also tried clearing all the device values in the device memory to 0 and re-write it to the PLC. It says writing is complete but did not seem to write the 0 to the PLC. I double check by using 'read from PLC' and the old values are still there. My colleague once told me that Mitsubishi PLC does not seem to be happy with 'partial download' of the program. This is what I did - I only downloaded 5 out of the 20 program that I have in the project. I wonder if this is the cause of the problem? I can't download them just yet as I have to make sure that all the device is within the range, etc (as mentioned before I am modifying an existing project). I would appreciate if anyone of you can help me with this problem. Thanks, MS10

[Crossbow]

I replied to your other post on the same topic.

[Gambit]

I take it you are using a system Q CPU. I don't think your colleague is to familiar with Mitsubishi PLC's either. You will need to download all the programs which are selected to run in the PLC paremeters if you don't the PLC will go into error because it can't find the program to run. Would be a strange PLC if it didn't. When you format your PLC everything is gone. It looks like your downloading a Device memory file which has the old values. You should change this file or not download it at all. Check your device memory and your Device init settings