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Guest mwatkins

Plc2 upgrade to slc5/04

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I have been given a project to change out a PLC2 (I never programmed a PLC2) to a SLC5/04. Where can I find definitions for the instructions used in a PLC2. I don't have the software for the PLC2. Example FWM (file to word move) and SQO (sequencer output). Which SLC instrunction should I replace these with. Thanks for any help given.

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Why try and figure out the command conversions and give your self a headache , if you know what the PLC is going  to do then make the most of the new PLC be use of a structured programming approach and rewrite the software to match the new hardware.

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Wise advice!  

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The memory structure of the PLC-2 family is quite different than that of the SLC.  Also the instruction sets of the two platforms, while similar, are different in many respects (math functions especially).  I/O is completely different.  With your lack of experience with the PLC-2, a rung-by-rung manual conversion would be frustrating and time-consuming, but not impossible.  Although not knowing details of your workplace, I don't know that it would be worth the effort to backtrack and learn the PLC-2 system just for this conversion.  A PLC-2 to PLC-5 (similar memory organization to the SLC) converter is available from AB but beware ... it is not (necessarily) 100% effective.  A manual check would still be in order (IMHO).  I, too, am about to enter a project which will require this conversion (actually a PLC-2 to PLC-5) and I will be doing it by hand.  Bottom line: find someone with the experience to assist you with the conversion (email me if you'd like - I'm available) or start from scratch (as has been suggested to you earlier) yourself.  Either way, good luck!

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I used to work on plc2 and we used those instructions in one of our programs.  I just took a look at the Manual for PLC5 and SLC.  I think PLC2 was the same instruction as these show except for the addressing.  Look in Chapter 6 SLC500.

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I have changed a PLC 2 to a PLC 5. I rewrote the logic. It is a good time to look at what the logic does and rewrite sections of it. The PLC 5 or SLC 500 have some additional instructions which were not available in the PLC 2, which may simplify the job. I'm sure you can come up with a better way to do it. An added benifit of the PLC 5 is that the PLC 5 can also use the same rack and same cards as the PLC 2. Makes for an easy swap.

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