I am looking to integrate several green systems together and will need to both control and monitor the systems.  I would prefer to work with a quality PID system that has a lot of expandability but most of all, I need to source sensors and such or a system that can be configured with either digital or analog inputs or standard thermocouple inputs. 

Sensors required would be standards pressure, temp, flow rate, etc.  I would also like thermistor options which require scaling.  I also need interface with meteorological sensors but I may be able to just directly interface with a PC for that. 


I need all this to be configurable via PC.  I have used PID systems recently that are all setup with included PC software but are WAY too pricey for my residential setup.  

I would also be interested. In my previous life, 35 years ago, I designed and installed these for industrial and commercial buildings and then latter for weapons testing with price tags to match. In my spare time I've played around with some Arduino and PICAX applications which could easily be used as front ends. I have yet to find a flexible and inexpensive turnkey solution though.

We use Programmable Logic Controllers (PLCs) for our integrated Passive Solar and Hydronic Radiant Floor heating system designs. Most PLCs these days have PID control methodology built in. We have become very fond of the Allen Bradley (Rockwell Automation) Micro800 family of PLCs as they only cost a couple hundred dollars. These PLCs can be programmed from a PC using free software available from Rockwell Automation. The sensors that you can hang on them is nearly endless (i.e., via expandable module approach) and they are commonly used for very complicated industrial control processes (i.e., they are robust and fault tolerant).  However, you still need to understand ladder relay logic and you also need to be competent with programming in general.  There are some good PLC programming books to help you master this.

The Micro850 also has an ethernet port that can be used to connect the PLC to the internet. This allows us to remote access our customers control systems (i.e., for setup monitoring and easy troubleshooting) and also allows us to host some of our more sophisticated control algorithms on the cloud (i.e., our file servers) to offload the storage from the PLC. I’ll post a photo of a Micro850 PLC and some of my recommended PLC programming books when I can get a chance.

Yes, we are big fans of Arduino too. We use these for many of our home hobbies/projects.  However, we would be very hesitant to use one for a customer control application.

Here's the promised photo...