DONT LAUGH !! Getting back to DOS and PLC2.

Forrest Gump liked to say “My mama always said, ‘Life was like a box of chocolates. You never know what you’re gonna get.'”

I think his mama was saying, life is full of circles. Circle of life that is. I started out with PLC 2, 3, 5, .... and now I am back with the PLC 2 machines.

Gone are the days with T2, T3 industrial terminals, the lunch box, the T45, T47 laptops..... and oh yeah, the cassette tape recorder.



Imagine that carry one of those to the airport nowadays, they may think it contains some sort of explosive device :=)

[To be continued]

A substitute for the cassette tape recorder these days is using the sound card and Audacity software. Audacity will record or playback as a .wav file. To save to the computer, plug the audio cord into the Mic input and to save to the PLC, plug the audio cord into the audio output of the sound card.

Over the past 15 years or so , a few had tried to upgrade the machines, none succeeded yet. Now, it is my turn unfortunately. I've had all the designs and developments done ( a new CompactLogix couple with AAHMI), just waiting for them to be wired and tested.
These machines are a little bit complicated, besides the usual IOs, VHSC, a 1771-KA2 is DataHighwaying to a KE module then RS232C to a DOS PC. What impressed me most is these 1980s DOS machines are able to access PLC's data address and communicate with the plant network onto a SQL DB.

Trivia Time: How does a DOS PC access PLC data?

[To be continued]

I would not take that as hand luggage on a flight indeed.

BachPhi said:

Trivia Time: How does a DOS PC access PLC data?

Click to expand...

Individual lines in a parallel port connected to digital I/O's on the PLC? Some kind of RS232 connection? At least the DOS machines could talk RS232 reliably (I see more problems with that on current Windows machines).

BachPhi said:

Trivia Time: How does a DOS PC access PLC data?

Click to expand...

As a Gen Y Ethernet fanboy, my answer is just going to be:

"very slowly, very reliably, and in a completely undocumented way."

I did work on Siemens S5 PLC's and MS-DOS early in my career, so I can at least appreciate the robustness and reliability of the old gear, and the sheer ingenuity of older programmers at making such a limited system do such complex things

i even had to switch it on at airport, the S5 can still be programmed with the PG95, it has floppies (5.25) so is this old?

Ten years ago, I had to adopt a policy that I'm not going to talk about anything but the weather to a PLC-2 customer until they write a purchase order.

No guessing. No "just for old time's sake". No "I'm sure you've got one back there someplace". No "don't you like a challenge ?".

And definitely no "but it's so old, software should be free".

S5, lol. I had S3, now one number come to my mind , PG675. I just googled it, Yup I was right, darn , not bad for my memory.

Back to my story, a term that was popular: "Terminate and Stay Resident" driver is loaded in Config.sys , the software was made by AB I think and is called Interchange. It enable DOS PC to access PLC2 address directly.

Now on to the fun of getting connected to PLC2:

1. I built an XP laptop with a real 9 pin serial port and used it with a "smart" cable. I know Rockwell has a smart serial cable, 9399-L2103, but I am not sure what mine is.
It's a black cube with 15 pin on one side and 9 pin on the other side. If you can identify what it is let me know.



The software I am using is AI-2 6.25. AI-2 is made by ICOM I think, they were later bought by AB. Being able to run it on XP is nice, it's still a DOS software but able to run on XP.

The other day, it stop communicating, and I was pulling my hair out, I then tested the serial port itself. sure enough, my port is bad. It can receive but not sending.

I was thinking that I have to buy another old laptop that has a real serial port, but decided to try with a USB to Serial adapter. I have a really good USB serial adapter. XS880 made by USConverter. AI-2 software allow to change between COM1 and COM2, I force my USB adapter to get COM2. Sure enought, it's working good for me.

Next I thought, I dont really need a laptop with a real serial port, matter of fact , I am going to build a VM machine and host piping the serial port. Sure enough, it is working for me as well. That's bring up a really good potential here, where I can bring a VM machine anywhere at any time.... !!! that is not limited to an old laptop!!

[to be continued]

2. The second option to connect to PLC is to use a PCMK/B card along with 1784-PCM2 15 pin cable. From what I read, It seemed that if you have KA3 card, you can connect with it using XP, but since I have a KA2, there is no chance for it to work in XP but only in Win98. I did not want to have a specific machine tie down to Win98, so I built a win98 that boot and run on a USB thumb drive with AI-2 software. After some challenges, I managed to load the driver for PCMK card in win98 and from there I was able to go online with PLC2 controller.!!! I now have a USB thumbdrive at disposal that I can take it with me and go online with PLC2 controller :=)

http://infiniteautomation.com/ has a capable free edition and partly open source product if you want something web based

BachPhi are you porting the PCMK car to you Virtual machine?

No, there is no driver for PCMK in a virtual machine

V0N_hydro said:

http://infiniteautomation.com/ has a capable free edition and partly open source product if you want something web based

Click to expand...

Seriously?? more like you just want to advertise about your product.

I have one of those digital cassette recorders and a T50 terminal. Both still work.

jvjr said:

I have one of those digital cassette recorders and a T50 terminal. Both still work.

Click to expand...

T50? oh wow!! that thing is heavy and big! It used KT card , right?