Real time systems + .NET

Lately I've been doing a lot of PLC interfacing with .NET. It poses an interesting challenge. On one side you have a highly scalable web/windows systems with multi users sending many requests. On the other side you have an extremely solid system with a very finite series of states. Making the two talk together nicely is quite an interesting and fun challenge.

One of the problems that we were having last year was the state of the PLC getting out of sync with the application system. PLCs are not meant to respond to multi requests. One idea I'm implementing to fix it is a super-singleton like object to queue incoming request and send them out to the PLC in series.

So far it's turning out okay, but I'm looking forward to production system "hum". That will put a huge smile on my face :)


I was looking at some smaller PLCs for home use. I was thinking of automating my sprinkler system with one. The MicroLogix 1000 looks about the right size. Here's some of the features:

- 24V dc inputs and relay outputs with a 24V dc power supply
- RS-232 communication port configurable for EtherNet/IP communication thru an EtherNet/IP-to-RS-232 interface
- controller contains the power supply, processor, and all its I/O circuits packaged in a single unit

I found one on ebay for 125 bucks. Not bad.

One wild idea I have is to use it to program Christmas tree lights. Ahhhh...maybe then I'll be motivated to hang the lights ;-)