Mitsubishi FX-16MR communication

[bboddy]

I have several of the older FX model programmable controllers along with the two dozen that we are using. Having problems communicating with the extension input or output modules - just starting this post and can provide more detail - just fishing to see if anywhere has had issues with the FX series. thx.

 

[twocozz]

We have found the FX series to be pretty much bullet proof (we have several hundred on site). Never had a problem with digital I/O extension units as they just map automatically into memory. Are you referring to Analog I/O?

 

[bboddy]

Thx. two - we are connecting to digital I/O extension units. The specific problem is that the OEM stored the memory in the FX RAM and I am copying the program to FX-EEPROM-4 cassettes to prevent loss of program and ease for our technicians. The data is being transferred by using the Mitsubishi FX-20P handheld programmer. I copy the program, program check, and verify with no problems. The issue is that I have 7 FX controllers - 3 of them will not show communication to the extension modules and 4 of them have varying degrees of output issues. I know that you would need to know more specifics about our system but is their something I am missing when copying these - I have the Mitsubishi info and it shows this as a simple operation. thx again

 

[twocozz]

Sorry to say I haven't seen this issue before. The procedure is straightforward like you say and you must be doing the transfer correct for the verification to work. It's just a stab in the dark but how big are the PLC programs and will they fit into the 4K EEPROM (do you need the FX-EEPROM-8?). You could look in the program to see how big they are (searching for the "End" instruction is quickest).



My weak theory is that the code that drives outputs on the extension module are in a part of memory that is not saved (>4K) and the verification procedure works because the 4K uploaded is the same as the 4K in the PLC (you just need the rest of it).


Other than that I would give Mitsubishi a ring (but if they are anything like the UK their support is dire).

Regards

 

[bboddy]

Good info two! The rest of the story is that we have 8 of these machines running and I was able to copy and install 6 of the 8 with no problems. Now I am assuming that with the EEPROM installed, that this is the first path that the PLC will reference for instructions. Also the original EEPROMS that the vendor provided were 4K EEPROMS. Still looking into this.