Hello guys, just had a few questions, wanted to get your opinions on addressing in RSLogix5000 on a CompactLogix L36ERM. So, a little background, we have around 40ish die cast machines in our facility. Up until recently they have all been run by PLC5/30s running RSLogix5. We recently have upgraded 4 of them to CompactLogix L36ERM. For the very first one that I did, I used the program conversion tool so that I could keep the same logic. I had to make lots of tweaks to it and finally got it working correctly. We used direct addressing for that, as in if I have a "Die Open Limit Switch" wired to input module 1, input 5 I would address it in the program as Local:1:I.Data.5 rather than making a tag called "Die_Open_LS" and aliasing it to that address. So, everything was direct addressed, got it running fine, then did the next machine. The next machine had some different i/o so we had to change the addressing a little, maybe now the die open ls was wired into module 3, instead of 1, etc. All of the machines are a little different setup, but mostly the same logic so we just use the last program and make any necessary changes to it and then download it into the newly upgraded machine/plc. So my thinking is that we should just make tags of all of the inputs/ outputs and alias them to whatever address that they are wired into and then address them as the aliased tags in the program. That way whenever we move onto a new machine upgrade we only have to specify the aliased address in one spot, rather than all over the program, and it would be a lot easier. I figure I can even export the tag database and open with Excel and create new tags in there, which would be faster. My question is what are the advantages of using tags/aliases vs direct addressing, other than when the wiring of an input/output changes? Thanks!
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