Mini 2/15 PLC lost its program

I have a really old machine that was donated to my company.

The PLC is one of the oldest ones I have ever seen. It is a "mini"<-yeah right, 2/15 and came with a cassette tape with the program backed up one it,which undoubtably is useless.

But my question is,do you know if these things have memory or EEPROMS in them that would store the program in it like a SLC 500?If the battery dies and it sits without power is the program gone from these dinosaurs?

And do you know the module needed to attempt to put the program back on it with the cassette tape and any operator instructions?

Yes, an EEPROM chip was an option for the PLC-2/15 controller.

http://literature.rockwellautomation.com/idc/groups/literature/documents/td/1770-td008_-en-p.pdf

My recollection is that there was a 1770-SA tape drive, that was an audio-style cassette. The later 1770-SB used a data style cassette.

These are as obsolete and rare as the PLC-2 controllers themselves. After using mine only once in 13 years, management made me get rid of it.

You could try to find or rent one of those tape drives, but it might be just as effective to reverse-engineer the control program from scratch.

If you do decide to recreate the program then you can get third party programming software and a cable from http://plc2software.com/ for less than $400.

You can read a review of the software here.

In my just in case one day storage of junk
I have a cassette recorder
a T2 terminal that was used for programming
the cables needed
hopefully the manual
and to show my age the knowledge to use them

If you cant find anything locally for you make contact
and we could try to work through a resolution

I do agree with Ken though that a new program from scratch would be best.

Hi I can remember using a laptop as a 'tape unit' for a T3 terminal with software from Taylor. Not much use to your situation but just for info

In my just in case one day storage of junk

Click to expand...

Funny Gil47,
I had a large cardboard box labeled "Mick's to be used some day box".

I never threw things away.

Ken Roach said:

Yes, an EEPROM chip was an option for the PLC-2/15 controller.

http://literature.rockwellautomation.com/idc/groups/literature/documents/td/1770-td008_-en-p.pdf

My recollection is that there was a 1770-SA tape drive, that was an audio-style cassette. The later 1770-SB used a data style cassette.

These are as obsolete and rare as the PLC-2 controllers themselves. After using mine only once in 13 years, management made me get rid of it.

You could try to find or rent one of those tape drives, but it might be just as effective to reverse-engineer the control program from scratch.

Click to expand...

How did the data style cassette look? Mine looks like an audio style but did they look different?

Where would I look for the EEPROM?

Have a look at the first PDF I linked to; there are photographs of the EEPROM installation. These were actual chips with pins; they weren't a socket or a cartridge.

I believe that the 1770-SA was the audio-style tape drive. In theory you could play back your cassette and find some way to extract the digital signal, then decompile it through one of the old software packages.

In practice, throw the controller into a deep scrap bin as hard as you can.

Gil47 said:

In my just in case one day storage of junk
I have a cassette recorder
a T2 terminal that was used for programming
the cables needed
hopefully the manual
and to show my age the knowledge to use them

If you cant find anything locally for you make contact
and we could try to work through a resolution

I do agree with Ken though that a new program from scratch would be best.

Click to expand...

Thats really thoughtfull thank you.

To be honest with you guys I went to school for automation about 4 years back. I pursued engineering school,dropped out and got a music production degree. I just within the last year have been in the industrial maintenance field and just in the last couple of months have I been trying to get back up to speed on the wiring and programming side of things I was once decent at,but it was with RS LOGIX.

The point is that it has been awhile since I programmed a PLC and I dont know anything about the software or program differences with this kind of obsolete PLC. Though if it is gone there is not much for me to mess up its just convincing my boss of a small company to buy the software and putting myself in a position where I am saying I can reprogram may not be wise for me just yet. If I can get this tape machine cheap and restore the program I will be golden. Then when the pressure is off I will convince them to buy the software so it doesnt happen again. Then I can experiment with it and learn it.

So what would it take to get my hands on this machine to try out? I dont even know if the cassette is good anymore. It was sitting in the machine for what looked like a decade under a accessory 120V outlet.

Ken Roach said:

Have a look at the first PDF I linked to; there are photographs of the EEPROM installation. These were actual chips with pins; they weren't a socket or a cartridge.

I believe that the 1770-SA was the audio-style tape drive. In theory you could play back your cassette and find some way to extract the digital signal, then decompile it through one of the old software packages.

In practice, throw the controller into a deep scrap bin as hard as you can.

Click to expand...

Your the man. I just verified that there is no EEPROM in the slot and according to the your link the EEPROM is either faulty or uninstalled if the memory LED stays lit,which mine does. The batteries read 1.47V is that close enough to 1.5V to be good? There were corroded though and the Low Battery light was flashing.

So without power,batteries or a EEPROm how long will the program remain in this unit's memory?

http://literature.rockwellautomation.com/idc/groups/public/documents/webassets/browse_category.hcst

The link takes you to the Literature Library. About halfway down the right side of the page, Click on Programmable Controllers, then, Click on Legacy Products. Next, scroll thru the 4 pages to find manuals related to your PLC.

That's bad news if the Low Battery light was flashing. I don't think these controllers had any memory-support capacitors; the RAM was cleared instantly if the power went out and the battery was low or missing.

This is one of the reasons the late-1980's SLC-500 controllers got RAM support capacitors. You can pull the battery out of an SLC-5/03 for a month and the program will probably still be there.

My recommendation is to see if your local Rockwell Automation office or distributor has a PLC specialist who happens to have one of these tape drives.

If I remember correctly you could use the old Taylor software to read that data cassette. I 'm wagering that you had to use the 1770-SA though. I've actually got an original copy of Taylor software for PLC-2 on the top of my bookcase. I'm kind of short so I can't get it down from there If you need the SA there's one on ebay right now for $175.

Good luck,

(8{)} .)
(Yosi)