Mitsubishi Parameter Mismatch

Apart from bad management of program backups has anyone ever come across a problem with parameter mismatching when attempting to go on line to a Mits A-series or Q-series?

Parameter mismatches used to be a common problem for inexperienced Medoc users but I am not sure whether the issue still exists with GX Developer. The problem occured if someone uploaded a programme from a PLC but forgot to save the parameters before they quit the project. Medoc required you to save the parameters and the programme seperately. As there was alomost no reason for anybody to go into the parameters after the initial setup of the project it was very easy to forget to save this file.

I use Mitsubishi A and Q series most of the time. I have not found any problems with parameters mismatched.

Parameter mismatch occurs when you have set wrong or no parameters in 'parameter setup'

Usually it is the number and type of I/O you have plugged in.

Until you get the program on your laptop to match the program/parameters to the real physical ones - you will get this error.

You can either set them by looking at the rack and entering them in parameters - or by uploading just the paremeters.

This is i my experience a most common problem with them Q series.


I recall having this happened to me many times when I was programming some rack in my shop through a modem (direct to a serial card) or through the transparent port of an HMI (from a PCAnywhere setup) or through an Ethernet card.

Sometimes I had to re-download the hole darn thing.

Seems that 3 way programming capability was tooooo much for them

Sometimes I was loosing the serial card setup parameters and it was giving me these results.