# Omron Sysmac C20

J

#### Jody Gallant CET

We have been asked to bring an older lift station into a SCADA system we designed. Problem is, the old PLC that is in the station is Omron Sysmac C20. Are there any serial interface ports on these? where can I get info on this old unit? What software and cable is used to program.

It will probably be easier for us to pull this controller out and install a new one that I know will work. But we will still need to get the program out to make sure we keep the same functionality.

Thanks
Jody Gallant CET

G

#### Greg Goodman

> It will probably be easier for us to pull this controller out and install
> a new one that I know will work. But we will still need to get the
> program out to make sure we keep the same functionality.

I agree that you need to preserve necessary functionality, and that the existing control code is a good reference point. But I'd take the
opportunity to re-evaluate the system's control requirements, reconsider the design of the control code, and be willing to write new code for the new controller that meets your understanding of the requirements. I have, on a number of occasions, found that the code running in an existing controller needed significant pruning and, on occasion, a complete rewrite. If the system has been in place for awhile, and
undergone any sort of evolution, the existing code may include no-longer-necessary calculations, kludges around shortcomings that are
no longer an issue, implementations that reflected an imperfect understanding of the problem, disabled logic that has since moved
elsewhere or been obsoleted (or obsolete logic that has *not* been disabled, but whose results are now ignored) ...

The real requirements of the lift station control system today may not coincide exactly with the requirements as perceived when the old system
was put in. And the perception of the requirements then may not have coincided perfectly with the real requirements.

Greg Goodman

E

#### Eric Nelson

Hi Jody,

I agree with Greg's comments, but I think the changeover would still be a lot easier if you at least have a hardcopy of the existing program. You
can't plug directly into the 48-pin connector on the front, so you need either an Omron Programming Console (3G2A6-PRO15) to access the program and document it manually, or an Omron Host Link Unit (3G2C7-LK201) to use their
software on a PC. The Host Link Unit provides the RS-232 port that you could use to connect to your SCADA system. The bad news is that any of these
solutions requires finding the hardware. Before you ask..... I'm sorry, but no, you can't buy mine! ;oP

E-Bay <http://www.ebay.com> is a great source for finding obsolete equipment. I don't see any Host Links available right now, but currently,
there's a Programming Console for sale (as a package with a bunch of other hardware), bidding at $122.50 (US$). The seller has eight of these systems available. Of course they're used, but you're not going to find new stuff at that price! Here's the link:

<http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=590011492>

The good news is that Omron <http://www.omron.com> still has the manuals

http://oeiweb.omron.com/oei/TechManuals-PLC.htm
Hopefully this information will at least let you figure out what options you have.....

Good luck!,

- Eric Nelson
[email protected]
Controls/Software
Packaging Associates Automation Inc. [email protected]
Rockaway, NJ, USA

C

#### CK

Check with your local Omron office. I used to work for Omron, and most of their regional offices should have this equipment they can loan you to get a copy of your program. The LK201 mdule should still be available, at least it was a few months ago. Your local Omron office should have an application engineer who can assist you with this.

CK