looking for plans to construct a simple binary plc that would be able to control about six to ten relays.

 

Just buy a small PLC or programable relay off the shelf.

Rockwell pico realy or Muller easy relay or Telemecanique have small plc's/programable relays that include a programming screen built in.

steve

 

Since the header is PC, I assume you are looking for something that runs on a PC. If that's not correct, I'd advise looking at PIC or Rabbit or Zworld. If you want a simple PLC setup to do Logic on a PLC I have such a setup that I am using in production. It runs under Linux and uses an 8255 (DIO48) card to provide 24 in 24 out at ttl levels. Total cost would be about $100 for the card running on a PC you already have. This card, expecially if you get the H version will drive 5V relays directly. I have designed a companion card that provides optoisolation and high current outputs but if you simply need to drive a few relays you can get by without that. Using voltage dividers will suffice for inputs. If you are interested, email me and I send you the package. The cards can be obtained from "www.computerboards.com":http://www.computerboards.com . I can help you with the logic. (It's not graphical)

Regards

cww