Beginner PLC questions.

First off, I apologize If im asking questions that are way out of my experience level.


I work for a company who has 5 different owners, in 5 years. We have several plcs across our property. They are all slc500, or the old PC5 systems. Each system only have about 15 inputs, and 15 outputs. Not too complicated.

Since we have been under different management, the guy who used to take care of our plcs has left the company years ago. Now, we need to do a little work on the ladder logic, and the company ask me about it. I have just taken a couple classes over plcs, basic ladder logic, and wiring. No one else has any idea how they work.

I was wondering if i need copies of rslogix 5 and 500, or will 500 cover both ? Also, will it be a problem what we dont have the ladder logic backed up ?

The PLC 5 and the SLC 500 do need separate programming packages. You should contact your local Allen Bradley distributor for pricing etc. You should also tap them for technical assistance.

If you don't have any printouts or saved programs you can upload the logic from the PLCs themselves. However, you will not have any comments or nicknames, which will complicate your understanding the logic. It will be possible, but time consuming, for you to understand the programs from your knowledge of how the machines operate.

If at all possible contact the departed employee. He may have copies in his possession or know of some location for the original programs. He may also be willing, on a consulting basis and for a fee, to help you reverse engineer the logic.

do an EXTENSIVE search through old computer hard drives - desk drawers - and so on ... you're looking for files which end in .RSP (for the PLC-5) and files which end in .RSS (for the SLC systems) ...

note that if your systems are VERY old, then the files might end in .X5 and .ACH ... no matter how much time you spend searching, it will be worth it if you can find the copies that you're looking for ...

another thought ...

your company MIGHT already "own" copies of the RSLogix5 and RSLogix500 software that you need - which MIGHT be "reinstated" by your distributor ... (your distributor should be able to research your company name to find any legal serial numbers) ...

this would be much cheaper than buying new copies outright ... the price tag on that software is likely to make it a lot better for your company to simply hire an outside contractor to come in and make the changes that you're talking about ...

Sorry for the long delay in the reply.

Thanks for all the replies. I have checked all of our pc's looking for any of the ladder logic files. I can't find anything.

Almost all the plc cabinets have schematics that list what every input is, so that will help out a lot.

Here is another question, I had. In our main facility, we use 3 pc's (6 screens) running factory talk to monitor everything. Everything works fine, however, when you bring up RSLOGIX it tells you that it can't find the activations. It says it's using Factory Talk activations.

Schematics are a start, but it could be a very involved process to properly document your program from scratch. Someone will essentially have to use the schematics to document the I/O and work their way backwards to document the rest of the logic to make any changes possible unless the programs are very basic.

I'm not clear on what you mean by bringing up RSLogix on the Factory talk machines. Do you mean that RSLogix5 (for the PLC5) and RSLogix500 (for the SLC's) are also installed on those machines but with no activation? If so then it would be good to follow Ron's advice and work with your rep to determine what your company owns concerning those licenses. With all the changes in ownership, they may be lost, someone may have walked off with them, or the company may never have had their own license. Talking with your rep seems the proper action at this point.

I agree talk to your rep for the software.

But also If you can find any Contractor that has worked on the PLC may have a backup which you.could merge the comments. any new changes will be missed. but it's a big help still... I have had to.do this too many times for clients already... lol

also check for CDS floppy disks. USB sticks as well with the backups on them

If I may jump in, a little bit..

As Mr. Beaufort points towards, your company might actually own the licenses. It is very possible that the old employee "took" the licenses with him, together with all back-ups/original code. Sounds to me he left on a bad note.

even if he "took" the licenses - your company MIGHT still "own" them ... it's sort of like the title to a car ... you MIGHT still "own" it - even if someone else is driving around in it ...

so ...

CALL your distributor (I worked for one for about 8 years) ... you MIGHT be able to have your licenses "reinstated" ... the basic idea is that Rockwell doesn't want to keep the real owner from using the software - just the crooks ... they'll work with you - if it's possible ...

just for discussion - buying the RSLogix5 and RSLogix500 software packages that you're talking about will probably run you something in the neighborhood of $8,000 ... your company might consider that to be incentive enough to check with the distributor about "reinstating" vs. a "new" outright purchase ...

also if your PLC-5 models are "classics" (PLC-5/15 or PLC-5/25, etc.) then you're liable to need about $1,500 worth of Data Highway Plus communications gear to talk to the old beasts ... we still haven't nailed that angle down yet ...

For DH+, we've had good luck using a Prosoft AN-X2-AB-DHRIO module. It connects to the PC via Ethernet. It's a little cumbersome since it needs an external power supply, but it's far cheaper than the $2k+ U2DHP module from Rockwell. Which is also very fragile and tends to fail easily.

Were not needing the software just yet, but i wanted to ask about the options.

However, Im thinking we will be able to call the company and get a license for the software.


Could someone help me understand how the license works ? I come from a network administrator and IT person. I just didnt know if its just a cd that has to be run, or a usb key that needs to be inserted, or does it need to connect to the internet ever so often ?


The computers in our main facility are running Factory Talk, and they are working just fine. I think everything in our main facility is slc500. However, one cabinet looks like it has a Control Logix inside of it. Not sure what it controls. It has no paperwork inside of the cabinet.

If you open up RsLogix500 on any of the PCs that have Factory Talk running, it wont let you go open any file or go online. It just says something about it cant find the activation, and ask you to locate them.

If you have a ControlLogix system you will also need RSLogix5000 now called Studio5000 or Logix Designer. You will need to get the correct version to work with your ControlLogix.

Alan

ps you can use RSLinx to see which version your ControlLogix is.