Mitsubishi programming help.

I have a Mitsubishi Q06UDEHCPU PLC with it being programmed in GX Developer. This is running a new Aida press in our facility. I was trying to track down the feed bar sensor. I found a wire number on the plug labeled X6D5. When I searched for that input in the PLC I found it is not used. I figured it was maybe a part of a word. So I looked up where in input was on the HMI to see if it had a different address. Sure enough it did. It was labeled MW27531. I have tried to find that in the PLC with no luck. I am relatively new to Mitsubishi PLC’s and HMI’s so I am not sure how to find this sensor. Any help explaining this would be greatly appreciated.

Hi
I expect the inputs are being mapped to M bits somewhere in the code

This is usually a move insturction to copy the input card word data directly to the M word data and means the M word is the same value until it is next mapped regardless of any 'do io'
type instructions

That is what I thought as well. But I can't find any reference to it anywhere in the code. I tried a cross Reference looking in all of the programs with no luck. I am sure I am missing something. But I just can't figure out what it is. In the HMI, Is the MW27531 a word bit? How would I search for that in the PLC? If I type in the exact number it says the syntax is incorrect.

For each input card find the address for the very first input, say X20 for example, and search that

Look for an instruction that is either a MOV or a FROM instruction

It maybe 2 or more cards are mapped in one MOV or FROM if the cards are next to each other so you would need the address of the first bit of the first card