AB PLC2 Program Conversion

[The Plc Kid]

If RA had made a Logix CPU for the 1771, no-one would buy anything else.

Now there's an idea.

I 100% agree it is real hard to kill plc 5 hardware. We have had coils short on outputs that were not fused and still lived.

On a slc that would take out the whole module in many cases.

 

[jude]

As has been said we converted 4 5 unit printing press,s from plc2 to plc 5 they run independantly or in combinations of 2 or 3 with a plc 5 as a supervisory been running like this for more then 10 years the only components we changed were power supplies in the racks,recently the engineers considered upgrading to 5000 but decided that doing that would not gain them anything.

 

[TConnolly]

One really big thing to consider in favor of a PLC/2 to PLC/5 conversion is that if you biff it big time on the program conversion (and hopefully improvement) and if you have to go back to the drawing board its easy to undo - just slip the old PLC/2 processor back into the chassis and production is back up and running while you head back to your desk to fix the PLC/5 program.


If you have any ControlLogix equipment and Logic5000 already then Jesper's suggestion of using a CLX processor and a 1756 DHRIO card in a 4 slot CLX chassis and a 1771-ASB in the 1771 chassis is a solution that is well worth considering. It also has the same advantage that if you need to go back to the drawing board you can unplug the ASB and put the PLC/2 back in and production can be back up and running while you rework, yet when you are done you have a CLX system with all the power and features.

 

[mellis]

Just swap processors to change a plc2 to a plc5 will only work with some PLC2 processors. I've done a few plc2/30 conversions, it's a bit more complicated.

Another hardware issue to watch for: Some really old 1771 racks won't work with a plc5.

I also am not generally in favor of the conversion program. I've used it effectively, but it takes a lot of work to get usable output from it. Trade off is eliminating typos from reentering the program vs extra time to make the converter output useful. With a big enough program, I'll use the converter.

There are some areas that will not convert at all and may take a bit of detective work to convert. Messages are done in a very peculiar manner. If you see rungs at the very beginning of the program full of GET instructions that seem to make no sense, that's probably a messge.

 

[TConnolly]

IIRC, the 2/30 used an external memory board. And as already mentioned the mini requires a power supply swap.