Paolo_911

Remap I/O addressing

8 posts in this topic

I swapped out an old A-series PLC with a newer FX3U-64MT/ES PLC. The converted program is now in GX Developer, as opposed to an old DOS based system I believe.

My job was to rewire the new I/O and land it on the PLC. The problem lies in the addressing. The old system used hex addressing x0-XF and so forth. Outputs also started at Y020 (instead of Y000).

My question is where in GX developer does it show the module addressing besides the "List of Used Devices"? Can this addressing be changed and manipulated or is it hardset? I just don't want to relabel all the wiring or change the program to accommodate this and have the wire labels be incorrect. What would be your advice as the best solution? 

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  Unfortunately FX's are hardset so there is no way match up input/output #'s. A better solution may have been go to a QCPU. Even with that I don't think GX developer will do a conversion for you, but the addressing will match which would be 1/2 the battle.

  If you must stick with the FX depending on the complexity of the program I would do a bit exchange in the ACPU program from for let's say X**8 - X**F and change them to all M bits with similar addressing to what it will end up as in the FX. For example if the current X bit is X00F and you will land it to X20 on the FX I would replace X00F with M2020 (or anything that ends in a 20). Then after copying and pasting it to the new FX program you can do a batch replace (M2020 --->X20)

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Missed the part where it was a medoc (dos) program. If you can't upload the program with GX developer (try it if you're not sure) the copying and pasting obviously won't work. Still recommend a Q in place of the FX if it's possible to keep from changing labels. I generally go no lower than a q03udecpu that way I have a built in ethernet port, but if your system is that old I'm sure a basic Q01 would be just fine.

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Just remapping the I/O might still cause problems.

The A series and FX series use a lot of different instructions that are not interchangeable.

And a lot of different memory areas and bits.

 

The program will need checking line by line.

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Wow, Thanks guys! I am totally disappointed this morning, but very thankful for your replies. I appreciate the advice. I could technically go with a Q series CPU, but my manager had already given me the FX and I mounted it to the DIN Rail, not to say I can't just swap it out. We do have spare PLCs of both FX and Q. I am still unsure of what I might do and may just spend the time to relabel the wires, or leave it as is for now. I'll have to think about this some more. I suppose I am going to have to look at this program over thoroughly and check it line by line. It is a fairly simple process so I might be able to just troubleshoot it. We'll see. Thanks again for all your help. 

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If you must stick with the FX depending on the complexity of the program I would do a bit exchange in the ACPU program from for let's say X**8 - X**F and change them to all M bits with similar addressing to what it will end up as in the FX. For example if the current X bit is X00F and you will land it to X20 on the FX I would replace X00F with M2020 (or anything that ends in a 20). Then after copying and pasting it to the new FX program you can do a batch replace (M2020 --->X20)

Personally I would do this but leave all inputs as flags within the program and then simply at the beginning of the program map the physical inputs to the ones declared as flags. I'ts then easier to simulate inputs for testing etc. Same if you need to change your IO around. The program becomes independent of it's physical I/O.

 

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The only logic difference I found so far is the use of the BSFL command which isn't supported in FX.

 To replace the logic  ---|| M240 ----------[ BSFL M240 K10 ]

 

could I use ---|| M240 _______________________________________________[ STFLP M240 M240 K10 K1 ]

                                              |______ (parallel branched off same rung)___[ RST M240 }

???

The reason for the reset of M240 is because BSFL places a 0 in M240 after it shifts left one bit. The FX PLC does not support the BSFL command thus leaving me to use the STFL command. Would this work? I am unsure if it will work exactly the same.  

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The STFL would work the same without the reset but you will have to have a different trigger.

 

My suggestion (as I have done often) is write a small test program using the bit shift and see how the bits shift.

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