HMTL requests -- sensors -- PLC

Looking at pricing of door/window sensors (any kind of sensor really) and it occurs to me that not every sensor needs to be wireless and have it’s own zwave communication. The first thing I thought of was using a PLC to capture all the switch/sensor data and the either send it to vera via HTML or have Vera be able to poll the PLC.
A decent PLC could be set up for $200-$400 and it could do a lot of the heavy lifting that doesn’t make a lot of sense for zwave. For instance instead of the vera polling every window to see if it is closed it could simply ask for window status, secured or not. Most PLCs can be programmed by ladder logic or BASIC and thus could do complicated logic for the VERA. Since PLC’s are made for factory automation you can do everything thing from motor control, complex data collection, temperature control, voltage control, position sensing, etc. Any project that required more than a couple of three sensors would pay for itself. For instance a scene for on the patio at night, adjust lights (based on ambient light), make sure sprinklers don’t come on, turn variable speed water fountain to a pleasing setting…

You could talk to the PLC via serial, usb or ethernet.

Another thought, relays and power switching would be much cheaper…

I think I’m just rambling…

Why not try an integrate an alarm system to do this. All 3 of the alarm plugins will expose the sensors to vera.

Strangley is correct. I work with PLC’s all the time and I know what you are thinking. The plus to the alarm system is the cost, no programing, integrated motion detectors, fire, and more. You are correct in your thinking to remove the load from Vera in regards to polling…it doesn’t have a lot of power, but in this case I would recommend a security system. (Wired always works the best if you can do it.)
Regards
Tim Alls
AllSeas Yachts

That’s a good idea. The only thing it doesn’t get me is outputs to relays, but maybe I can live without that…

What is the application for the relays needed?
Tim

Don’t have anything in particular right now but I was thinking about but I was thinking about doing some automation on my pond. Also would work well for sprinkler control.
If I had the PLC working anyway a $10-$20 relay sounds a lot better than a $40- $50 Z-wave one.