PLC-5 Chassis and Compadibility with PLC's

Hello everyone!

I recently acquired some old PLC-5 Chassis and IO modules. The one chassis is a 1771-AB (8 slots) and the other is a 1771-A4B (16 slots). I was wondering if I moved the power plug in the smaller, 8 slot unit, if the processor would function in it. It seems the way it is built that it is only meant for remote IO and not to operate completely on its own. 8 slots is a lot better size for any project I would be doing.

Thanks!
Weston

What exact power supply module part number do you have ?

The 1771-AB was an "Original" chassis, built in 1979. It's identical to the 1771-A2.

Those were built for the PLC-2 controller and its old RIO adapters, so the power supply that's in it will probably not fit a 1771-A4B chassis or support a PLC-5 controller.

Years ago on a test bench I was able to get a PLC 5/15 to run in one of the older style chassis by building a "jumper" cable out of the bottom of the chassis to the power supply cable. I think the main problem is that the power supply plug with the cable plugged in physically interferes with the the processor. The original adapters that were intended for this slot had a cut out in them to allow for cable clearance. I think a slot mounted power supply would probably work assuming the processor and whatever other cards in the chassis dont overload it.

It is a "Bulletin 1771 I/O Chassis" Catalog number: 1771-AB Series: J The power supply is a 1771-P2, and I have connected the cord to the molex connector on the A4B chassis to power it.

Remrun: Yes! That seems to be the problem here. I was wondering if I moved the power cord to the bottom if it would really work, or is a waste of my time.

The 1771-P2 was built for the PLC-2 family of controllers from 1978 until about 1992. The fact that it was mated to a 1771-AB chassis suggests it's an early one.

For those of you who are reading along, it's a power supply that is bolted to the side of the chassis and connects with a Molex-to-Molex cable, part number 1771-CD or 1771-CE.

It will work with the 1771-A4B chassis, but only to host a 1771-ASB Remote I/O adapter, or a PLC-2/xx Mini PLC2 controller.

I can't speak to what might have worked with a jumper modification.

I've done a handful of PLC-2 upgrades that used the 1771-P2 power supply, and we replaced them all with 1771-PS7 supplies.

The power supply did work for me with a PLC-5/11 processor in the A4B chassis. Are you saying the processor will not work in the 1771-AB chassis with a modification to the molex connector?

It was never designed for this. You run the risk of damaging the components in the chassis. Are you comfortable with that possibility?

OG

I don't know if I am really comfortable with those odds, I'm thinking it might be a better idea to find a used one on ebay or something like that.