Old PLC

What is the oldest plc do you know or have you worked?
In spain till the end year´s 80, plc wasn´t very used.
There were allen-bradley (plc-2) and modicon (a-145). What kind of plc´s there were in other countries?
regards.

I think you a little bit off, I would say 70s instead of 80s:

It was a lot of PLCs in early 80s in Europe:
Siemens was one of biggest (S5 as I remeber),
PLC (1778) and PLC2 started in 70s.
Many Japaniese PLCs were is use that time.
PLC5 was introduced in Mid-80s.

Hmm... The venerable GE Series One?

TI-500 series

Well, its not really a PLC, but it was a DEC PDP-8A set up with several interface boards for machine control.

The first PLC I ever encountered was a TI.

Next was the GE Series One. I was working with one of those just last week. But the GE Series One can still be purchased brand spanking new as the DL305 from Automation Direct.

My first "PLC", in the sense that it was a programmable (sort of) controller that used boolean logic was the Allen Bradley Cardlock product. You mounted a bunch of cards with different logic gates on them and wirewrapped the gates together. Cards included multi-input AND and OR gates, one-shots, time delays, etc. This was late 1970s.

Almost as much fun as analog computer lab in college.

I think Cardlock was around in the late 1960's.
The first plant I worked in after tech was using Norbits - anyone heard of them? Philips had stopped manufacturing them before I got there (1968) so they were making their own. Simple RTL using discrete components. From memory, I think AB's Cardlock used the Motorola HTL IC's.

Down here in NZ there was a locally made system called HiLog that was popular in the 1970's. A lot of it was sold into Aus as well.

The first PLC I got hands on with was th AB 1774 (around 1978).

First one I ever got my hands on was the 5TI by, well, who else, TI. That would have been mid-80's for me but the PLC itself was no youngster then.

When I used it there was an I/O family called 6MT-xxxx which was 4-channels per module (digital only, no analogue), but previous to that it had used the 5MT with, wait for it, 1-channel per module.

The main thing I remember of PLCs in those days was the weight of the "portable" programming units, the VPU200s. I think that accounts for why my right arm is still about 3 inches longer than the left.

regards

Ken

first plc

1983 -Out of college ,started working on the AB-1778.
(I think that was the model no.)After a few months started the first projet on PLC2/30.
2005 -started first project with contrologix

The oldest CPU's I have ever used were these things:

HP2100A

I used to look after a bunch of them being used in Paper Machine Measurement and Control systems (Measurex) for about 7 years.

I believe they were the first generation of computer made by HP and a derivative of them were used by NASA in the Appollo missions. Those guys were a LOT braver than we know.

I have worked in 1980 some AB's with ferrite core-meory and Simatic S5-110A/130A-K with EPROM and external timers.

Relience Automate 35

I wondered that no body has mentioned the Automate 35 of Relience, that was a real good PLC at that time.

However the programmer device ( Haziltine 1500 if I still remember) would for sure elongate your right hand by 3 inches long.


Cheers
Hagos

Square D class 8881 PLC. True boolean logic, Magnetic memory standard, 2 "working" math registers only if you order them as an extra. I remember when a "computer based" programmer was introduced in the late 70's. At that time programming using relay elements (ladder logic) was not available.

Steve Bailey said:

Almost as much fun as analog computer lab in college.

Click to expand...

Most "big" electronics parts mail order companies in the 60's had an analog computer in their catalog.

I remember Olson, McKee?, Burnstein-Applebee, and many others. And you had to have an Allied and Lafayette catalog, too! Even Radio Shack, who was privately owned out east (Massachusetts?) had one, and may have been up to 3 stores.

I was trying to explain the old analog computer recently. I was using my "circular" slide rule from electronics class as an example. Well, when dealing with these young whipper snappers, circular don't make sense, and they had never seen the "slap stick" version either.

Back to PLC school.

Draw a sketch of a simple circuit, with a NO switch, NC switch, relay, and light. Now, convert this into logic. Now, go to plcs.net and ask someone to write ladder loggic for you!

regards.....casey

BTW: The first plc I ever saw, back in 1988, was my first plc project, a new AB PLC2. The oldest I saw a few years ago, was a GE proto-type. The boards were a quarter inch thick. These may have been made around 1965. Did see some of the original modicons, during a retrofit/upgrade. Technology was slow coming out here to the cornfields, and even bigger places, like Caterpillar.

My company was still using ISSC plcs until about three years ago. They were 8 point cards with a parallel bus I/O layout. It had specially designed monotor/loader that used a tape drive. A real pain to program. I think Honeywell took over the company around 1979. Our books were printed in 1977. The units weren't bad for their era. We had analog i/o, all types of discrete I/O, integer math instructions, sequencers, subroutines, a hardwaired watchdog relay module, and more. The biggest problem was the fact that an I/O bus (ribbon cable) problem could actually corrupt the program memory. It wasn't unusual to find a machine literally going nuts with all the output addresses randomly flickering, motors jumping around, cylinders cycling back and forth. I used to fix them with a good thump and well placed pieces of folded paper to keep the connections made. I was relieved to see them gone for the sake of operator safety, although the processor failures never caused any injuries, it was just a matter of time.