PC control

Hi all,

At my work I have been requested to retrofit an old pc based system. This system is about 20 years and the old hard disk is u/s. I want to first of all install a new motherboard + ssd which is no problem. The problem is to write a complete new program since the old program is not recoverable (so i've heard). This program is not all that long or complicated although there are about 6 dc servo drives to be controlled + temperature control and 8 pneumatic valves. The screen is used as a simple non graphic HMI.

What is the easiest/cheapest way to do this? I am completely new to this kind of programming but like a challenge. Do I need to install windows + programming softwear?

Thanks for any input.
Eric.

Sounds like a job for a PLC rather than a PC. How are the field devices being physically controlled by the PC? If there's some form of IO card in the original machine, that's probably well obsolete as well and you'd have little hope of finding a modern driver for it.

Sounds like this job needs a full functional specification to be developed and some design work done before you jump into this!

Hi Saffa.
Thanks for mentioning the driver problem.
I could leave the motherboard in but that still wouldn’t solve anything as the drivers were no doubt loaded onto the old hard disk.
Which brings me to your PLC solution, something I wanted to do, but the MD thought it would be easier the way I suggested earlier.
The good thing about asking here is that I now feel stronger when arguing my case for a PLC.
Many thanks,
Eric.

What kind of interface do the servo drives and temperature controllers currently use?

I am a big advocate of PCs, but I very very seldom recommend using PC based control in place of a PLC. Typically by the time you purchase an industrial grade PC system that you can rely on, you are not far from the cost of a PLC and standard PC.

If you lose the argument of PC based control, one system to look at is Beckhoff TwinCAT. You can develop and run your PLC program on a PC, then if it doesn't work out, you can transfer to a CX based controller with quite often no program modifications.

Hi Archie,
I’ve got no idea about your interface question if I have to go the PLC way I will need to look into that. Thanks for the Beckhoff tip.

You might want to look into doing a complete revamp as well. Trying to make new stuff run 20 year old drives might keep you busy for a good while.
Perhaps it might be time to redo the whole deal, that might actually save you some money.

build complete new, with a new small PC, for display and /or codesys programming like archie says.
also have a look at the arduino, maybe it will do the same job for less money.