A new fossil record

[Ken Roach]

Yesterday I added a new entry to the "oldest PLC I've worked on" record.

It's an original PLC-2, part number 1772-LN, Series A Rev B, in an 8-slot 1771-A2 Series A chassis. Manufactured in 1979, and running flawlessly until yesterday.

When I got the call, the owner said he had Apple computer based software that used to work to re-load the PLC-2, but that his technician hadn't been able to get it to work.

No way, I said. There was never an Apple-based tool for the PLC-2. The only Apple software I ever saw from A-B was a Macintosh Classic version of GML for the 1394 motion controller.

He was true to his word: In 1982, Yancey Machine Tool Works of Portland, OR built a PLC-2 memory upload/download utility that booted and ran off a 5 1/4 inch floppy in an Apple II. The computer and the disk still boot and run, but the serial card (there's a box of them, most marked "BAD") and the RS232/PLC-2 converter don't work.

I spent yesterday manually re-entering the program into AI-2 software (thank goodness they had a printout) and am building a DOS computer this morning to try to download the program.

Yesterday definitely brought back memories.

 

[mordred]

its amazing whats still out there makes yu wonder when you'll run across vacuum tubes.

 

[rootboy]

I've worked on a PLC-1, but that was years ago, so I'm not sure that it counted as archaic back then.

When we decommissioned it, AB took it back in trade for some free training for the plant.

The plant also had an old PLC that you programmed by way of changing wirewrap connections, is that old enough?

As for tubes, the lads called me out to help them service an old Monarch lathe one night.

I knew something was up because of the S***-eating grins on their faces, and sure enough, when we opened the panel, I saw that the drive was an old vacuum tube type drive.

The prints were actual blueprints (meaning that they were blue, not white paper with blue lines on it), and were originally drawn up two weeks after I was born.

But all it took was a couple of measurements, and I found that the tube for the field winding to the motor was bad. I had them rob a rectifier off of a DC motor disconnect and install it in place of the tube and they were back on business.

 

[PeterW]

PLC-1, never heard of that, I thought the first was the 1774 PLC (or was it 1776 ), big black box.

That was the only PLC I've ever used that could use the same Timer as many times as you like, saving and restoring the individual time base and accumulated values.

 

[mordred]

Ken from your pic it looks like you scrounged up an old 8086 PC where did you find that devil? Now I know I'm old if I can recognize it from the motherboard layout

 

[mordred]

scratch that looking at your post thats prob the apple series probably apple 3+

 

[OZEE]

Ken from your pic it looks like you scrounged up an old 8086 PC where did you find that devil? Now I know I'm old if I can recognize it from the motherboard layout

Nope - that's an Apple, so it would have a Motorola 6502 chipset, not Intel.

 

[David_Emmerich]

Maybe its not in the same class, but the concrete block plant down the street, where I used to work, still has some vacuum tube thermal time delay relays running part of the batching system....and my old Heathkit with the 8086 still boots and runs ok. Its funny, when I moved to BG in 1990, that old Heathkit was the fastest unit in our plant at a whopping 3.7 meg/htz ...

David

 

[John Hawkins]

got one

I have a 10" Monarch EE lathe with the vacuum tube DC motor drive. 1959 model. Still runs great. Looks new.

 

[Plastic]

AB is junk!

It only ran 30 years? AB needs to rethink it's quality standards. This product seemed to oultast only the 8-Track, Casette, CDROM, DVD, and MP3.

When I install a PLC, I expect it to last until we are all flying around in Nuclear Powered flying saucers.

 

[Alan Case]

Also why didnt AB design the PLC-2 so it could easily be programmed by a Vista computer?

 

[Operaghost]

Using a USB 3.0 connection

OG

 

[JeffKiper]

I didn't get to work on it but did get to see it running. They called it CardLock it had logic cards and all connection where wire wrapped. Looked cool they said that it was the starting point of the modern PLC.

 

[robertmee]

Ken, I knew of a GE Logitrol still running not too long ago. Circa 1973.

 

[bernie_carlton]

I'm waiting for: "I had to repair a Jacquard Loom the other day ..."