Hello,

I am searching for water meters and automatic water valves that can communicate using MODBUS protocol. By now I managed to find some water meters by Endress-Hauser, but no luck with valves.

I would greatly appreciate ANY information on the subject. Thanks in advice.

 

You won't likely find a valve speaking Modbus directly, so you want some I/O device speaking Modbus (a cheap PLC or I/O 'block' or RTU). Then use one of the digital outputs to control a valve.

I am not sure your BUDGET, but if you want a very cheap plastic valve (for example to use in garden irrigation), there is a nice $7 one here:
http://www.adafruit.com/products/997

If you have a bigger budget (or want to control say a 2-inch pipe), I am sure there are lots of simple valves which can be controlled with a powered Digital output.

 

Valves are machined chunks of metal or plastic that don't talk Modbus. But the positioner or actuator that drives the valve might talk Modbus.

A Google search for
valve actuator Modbus
will bring up a number of hits for actuators that talk Modbus.

I suspect you're looking for a smaller valve, so you might look at Belimo. Mfgs like Rotork build big boy actuators.

 

I see. Thanks for your reply, I'll dig in this direction then.

As for the needs, it's more about 2-inch tubes - the idea is to control university's water system.

The budget is not in question yet, right now I have to find as many different solutions as possible. Could you name some actual devices or companies that produce them? Or maybe some sites such stuff can be found at?

 

> As for the needs, it's more about 2-inch tubes - the idea is to control
> university's water system.

If you are controlling the 'life blood' of a university's toilets and drinking fountains, then you especially don't want a flaky solution.

Unfortunately, just a web search for 'modbus plc' brings up more data-comm companies than suppliers. I'd look at the mainstream players like Schneider-Electric, GE IP, Automation-Direct. I know Ge Ip sells the Nano as about $100 with Modbus comms. Don't forget the programming software. Some vendors give free (getting profit from hw), while others charge a $100-200 fee for the programming software.

Control by a simple PLC means a crash/reboot of your code won't cause the water system to 'hiccup' or glitch.