What do I need to talk to a AB PLC-3?

As I recall, AB didn't promote the PLC-3 for very long. We were warned away from it by our local distributor at the time. We pretty much went directly from using the PLC-2 to the PLC-5 family.

The local A-B office here has (or at least had as of last year) a T-45 terminal that they used for sucking programs out of PLC-3s for the few local people in Northern Calif. still using them. For liability reasons they would not "fix" them or reprogram them, the only contract you could get was for their Service Techs to retrieve the program during the process of converting to a Logix platform. You might want to contact the local A-B office in Houston and see if they can still offer that service.

For liability reasons they would not "fix" them or reprogram them

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I wish GTS had stood up for me like that. It was falling asleep at the wheel while driving 400 miles between that PLC-3 job and another one they had scheduled me for the next day that made me quit.

I still have my first A-B training certificate. PLC-3 in 1984. PLC-3 was the standard in automotive paint plants with a hot back-up and bubble memory. I spent a couple of years integrating A-B's RFID into PLC-3s. 10,000 words in 10,000 files. Huge.

Wow, this thread got more replies than I expected. I saw some of them before I left this morning. Thanks for the help!

UPDATE:
The PLC did indeed lose its memory; verified by cycling through the front panel keypad/display. And they did indeed have a backup program on a CD from 2006; the last time anyone had been online with it (date also corresponding to the CPU batteries).

The PLC is the main command & control hub for a ship loading dock. It has at least (25) PLC5s networked back to it in one way or another.

There are two XP desktops connected to it (serving as HMIs, running RSView) with the DH+ PCI card going to a KF2 box, back to the PLC3. They are both old as dirt and have floppy drives. They would be perfect machines for online programming but neither have DOS dual-boot or programming software.

Myself and a couple of guys from their IT department spend the day digging through dusty old PC parts, filing cabinets, etc., trying to find the software (they had it on a machine at one point - said machine may or may not have last been seen under someone's desk in or around 2010), trying to find blank floppies, trying to find a USB floppy drive, etc.; it was a really fun treasure hunt.

Downloaded DOS and burned to floppies, found an old IDE HDD, tried to install DOS on it, many errors because of using 25 y/o floppies, but after enough downloads, writes, retries, etc., finally got DOS installed. Found Ai3 on floppies, installed it, no master disk, no activation, but it would allow me into the "AB3" program despite complaining about no activation.

Alas, I found that this program is written in 6200-PLC3, not Ai3. Continue searching for software. Found & installed 6200-PLC5, which does not work with PLC-3 I found.

I left without fixing the problem. I hate that. But I had literally exhausted every possible option. They have a guy coming tomorrow who made the backup in '06. He still has the software. They invited me back to assist him and hopefully learn more about their system (unsure what to expect of the dynamic between us). I think they are shortlisting me as a candidate for hospice on this dying system. I'm not sure how I feel about that.

Thanks for the detailed update. It went better than I predicted !

Upgrades and migrations of big systems are exciting and challenging. Hospice care for dying controllers is less so.

It's been a while since I messed with DH+. It's just a fieldbus, right? Can I download a program from the old desktop the way it's already set up, through the KF2 box? I'm guessing not, but thought I would ask. That would be too easy. Probably need to run a serial cable to DB9 port on the PLC?

Ken Roach said:

Thanks for the detailed update. It went better than I predicted !

Upgrades and migrations of big systems are exciting and challenging. Hospice care for dying controllers is less so.

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Update/ migration is inevitable. So inevitable in fact, that I encouraged them to have a competitor bid it. I told them that I'm not available for a project of that scale at this time, as I already have too many irons in the fire. But if it's still in the same shape 6 months from now I would be happy to bid it.

If someone out there has the AI3 or 6200-PLC software and is willing to send me a copy, I would be very grateful. I don't think I'm asking for anything illegal here; I believe one of those softwares was free to begin with, and the other one is no longer sold. Both have to be long out of copyright by now.

6200-PLC3 was never "free"; it simply was not copy-protected and was widely pirated.

Neither of the software packages is out of copyright protection; in the USA, copyright of a work made for hire is 95 years from publication.

As a practical matter, Rockwell Automation does not pursue copyright violations for unsupported software.

In my opinion, PLC-3 upgrades should be left to companies who already have the experience and tools, or done in cooperation with those companies so that you are the "new local expert" who understands the process and installation and plant, who the customer can rely on for the next 25 years.

Ken Roach said:

6200-PLC3 was never "free"; it simply was not copy-protected and was widely pirated.

Neither of the software packages is out of copyright protection; in the USA, copyright of a work made for hire is 95 years from publication.

As a practical matter, Rockwell Automation does not pursue copyright violations for unsupported software.

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Thank you for the info. I was not aware.

Ken Roach said:

In my opinion, PLC-3 upgrades should be left to companies who already have the experience and tools, or done in cooperation with those companies so that you are the "new local expert" who understands the process and installation and plant, who the customer can rely on for the next 25 years.

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I agree. I was not ready when I first went out there. Walking in blind, I would have caused more problems than I would have fixed. And what you suggest, is what we are doing. I spent all day yesterday onsite with the Rockwell guy who has been servicing this PLC for the past 23 years. He showed me the ropes and told me everything I needed to know. I think he is glad to let it go; he is working on bigger and better things these days (like several million dollar engineering projects) and I imagine coming back out there is a drag for him. The problem is fixed now; he and I are both done out there. This is just for future support. I just don't have the software, so unless I can find it, he is going to be "the guy" each and every time. He told me that would be glad to give me the software himself, except he doesn't have disks anymore and it exists only on his 20y/o win98 local machine.