PLC quandry


Thread Starter


Several years ago my company purchased a piece of used paper converting equipment made in Italy. It's Approx. 10 to 15 years old, and uses a
Siemens S5100U (CPU103) PLC control. I'v been told we did not purchase the control program "ladder logic" with this machine. It was a $2000.00 extra!!! I'm wondering what the options are should we decide to have our own technitian reinstall the program, should it become necessary. I was told the program will fit on an average floppy. Dosen't 2K sound a little high for this little program? Assuming we get the program, how difficult is getting the software to install it with? Is it free? cheap?
or outta sight? Would an ordinary Lap-Top do the job? Would the OEM normally keep this program available? What would be a normal service
charge for reprograming this PLC?
Any replys appreciated.
Thank You

Zan Von Flue

I program the S5 100U (103). About the ladder logic for 10-15 years, I don't know. I use the programming software from IBH. It can switch
between the 3 programming types, if the original programming was not programmed directly in SCL(AWL). The LAD module is extra. Even if the
program was in LAD or Function blocks, the working program language is STL.
About the program size. 2k is ok. The S5-100 has about 20k.
Installing/changing/diagnostic(ing) the software and CPU is very easy.
I don't know the price of the IBH software(the company bought the program). The Demo can't make a CPU connection.
I use a normal laptop. With 1 serial connection.
I believe they keep the program for 10years, then I don't know.
Cost, I don't know. The S5 is very easy to understand and change. If the program is still in the CPU, you can do it yourself. There is no
S5-software protection. That means getting the s5 program out of the CPU is easy.
If wanted, I could help more.
just contact me at the e-mail address.

Michael Griffin

Siemens has a "mini" version of their "Step-5" programming software which will handle the S5-103U CPU. I believe that it is about a third of the price of the full package. It is similar to the regular Step-5, but only handles the range from S5-90U up to S5-103U (i.e. S5-90, 100, 102, 103, 95) and not any of the larger models (S5-115U, 135U). This software will run on a lap-top. You will find this software to be rather user-hostile. You will also need a programming adaptor cable which plugs into the serial port.

I would recommend that you at the least get someone to make a PLC program back-up for you. You can install an (expensive) EPROM module in the rectangular hole in the front of the CPU to keep the program for you if the battery dies. You should also download the manual for this CPU from the Siemens web site (this is free).

If this is the only S5 PLC in your plant, you might consider replacing it with whatever type of PLC you are using elsewhere in your plant. This approach is sometimes cheaper than buying new programming software and training people to use it. Whether or not this is a good idea depends upon a lot of factors not mentioned in your e-mail.

The 103 has 20k of memory, so this may be a fairly complex system (and so expensive to replace). Some types of I/O modules (e.g. servo module, etc.) can have programs of their own which also need to be backed up. Some of these modules require their own programming software which is separate from Step-5, so you should have a look at what is plugged into the rack as well. If you have any more questions, please let us know.

Michael Griffin
London, Ont. Canada

Donald Pittendrigh

Hi All

No programmer or program is required to load the PLC, the program should be supplied on an EPROM module which is transferred into the PLC by manpulation of the switches on the front panel of the CPU.

2K is possibly not a bad price to re-write the softrware, I would certainly be interested for this price. I would rather pay 2K to re-write the program and break all ties with the guy who sells a machine without the software, it sounds like he is trying to hold you to ransom, he wouldn't live long in my country with such an attitude.

Donald Pittendrigh