Old PLC5 Question

Hey guys, I've got an easy one for ya, but you might have to wipe the dust off to answer it. I've got an old PLC5 that is running right now. However, we have decided to cease the heating portion, and I have been assigned to eliminate everything possible from the PLC program. However, the hardware will all stay. I've got BTR's and BTW's to and from analog cards, and I'm just wondering, if I delete this, will the processor have any quirks or anything? I guess, should I expect some kind of problems or can I just blow these away. The IO config I will not change, so I'm hoping that the Block Transfers being gone won't cause a problem. Can anyone verify this for sure? Thanks.

Russ

I would tread carefully and do backups frequently. If any code in there is sensitive to scan time, it'll show up eventually. Other than that you shouldn't have any trouble that I can think of.

The frequent backups is a given. Thanks for the input.

Russ

The only thing I can think of is that the controller scan time and the I/O scan time will speed up. If there is code that depends on a particular scan time it might not work as expected.

If any of the BTR/BTW instructions were configured in "Continuous" mode, they might still be executed after the instruction is deleted ! I think that ceases after the next power cycle, and it was specific to an older firmware revision. Continuous Mode is very uncommon.

Otherwise, go ahead and delete the instructions and you won't have a problem. This is a good opportunity to do some backing up of this and other systems if you get the chance.