PLC2 to PLC5 Conversion

I am working on a PLC2 to PLC5 conversion. It appears that most everything converted ok but I am getting lost with all the math conversions. In the PLC2, I see alot of hundreds, thousands, etc.. math conversions. The PLC5 added a Bit Field Dist function in the new code.

Also, there is a thumbwheel which uses Binary so i am guessing I have to do a TOD FRD instruction to take care of that..

This is my first conversion and I am not familiar with PLC2. I started writing code with PLC5's..

Does anyone know if the conversion is rather painless. I just opened the project with RSLOGIX5 and it asked me a couple of questions, then converted it.. Is there some "Gotcha" involved with these conversions?

Thanks,

plcengineer said:

I just opened the project with RSLOGIX5 and it asked me a couple of questions, then converted it...

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I've never heard of that. I'm going to have to give it a try. As far as I know its not done that way.

AB has a program that will translate PLC/2 to PLC/5, but its very expensive to purchase. However they also offer a a conversion service; You send them the file, they run the traslator, and send you back a PLC/5 files. Check with your distributor.

Yes, you are correct.. The code was converted before it was sent to me. But, it was in A.I. and I was seeing that conversion take place from A.I. to RLSOGIX5. I didn't see the PLC2-PLC5 Conversion.

Sorry to be misleading but I found out what was going on..

Do you know if this conversion works well or are there issues???



Thanks,

That makes sense. I think the conversion software outputs 6200 format files.


I dont think that I would trust any conversion to be perfect - there will undoubtedly be some issues. This will depend a great deal on the application. Keep in mind that PLC2 did BDC math and spoke Octal. The PLC2 required GET instructions to do math and thats probably why got all those extra math instruction. Review it thoroughly. If it used any zone control you will have to change that logic to a conditional sub-routine. There are probably other gotchas so you need to check the program.

Here is the programming manual for the PLC2. Good luck.
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1772-um006_-en-p.pdf

conversion

You lucky SOB......(maybe) The conversion has been done for you. The conversion you talk about is translating AI into Logics. This is painless. I do not have that kind of luck. I have, and will be, for some time, rewritting PLC2 logic to PLC5. (4 down 2 to go). One warning... make sure the conversion was tested after the conversion, before you translate into RSLogics. If there was a problem, (and there very well could be) it will be easier to trace before the second step of translating to LOgics. If software was used to convert the program to AI, you want to make sure it is tested carefully. I am not sure about recent versions, but as recent as last year, the software gets confused on complex programs.
Have a good week!

plcengineer said:

Do you know if this conversion works well or are there issues???

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I've done a couple of these, but it's been a while. A couple of things I remember:

There should be a report that lists every thing that the converter could not translate correctly. You will need the old PLC2 program to help figure these out. (Either a printout or access to the files and programming software)

If the first few rungs look really weird with a bunch of get instructions that don't appear to do anything useful, it's the PLC2 version of a message instruction. Refer to the PLC2 programming manual to decode it.

PLC2 did not allow immediate constants (i.e. EQU N7:0 100) everything had to use an address. You may not want to continue this in the PLC5 version. All these values are 3 digit BCD. Watch out, they may not all convert to the PLC5's integer format automatically. I'm pretty sure it handles timer and counters pretty well, but watch out for comparisons.

You probably have already seen it, but just in case... Check out knowledge base document "A16647 - PLC-2 to PLC-5 Conversions" for hardware considerations.

Good Luck,

PLCengineer,

Another problem I had with a PLC2-to-PLC5 conversion, made with the A.B. conversion program, was that the I/O addresses do not convert correctly without some human intervention. If your Inputs and Outputs must be at the same rack and slot locations, then someone must enter the correct offset in the conversion program to make that happen. For my program, on the first trial, the I/O addresses were shifted by down by two whole slots. I had to ask for a second conversion (from a company who did this for hire).

I've got one of these conversions left to do here myself. This one has two analog servo drives on it. Thanks for bringing it up and reminding me of that looming future project which I am so excitedly looking forward to doing.