Analog limit alarm or comparator

[RyreInc]

I'm not sure of the best subforum to post this...

We are looking for a comparator, preferably DIN-rail mountable, that will turn on a digital output when a 0-10V analog signal reaches a certain configurable threshold. The goal is to turn a linear potentiometer into a switch so that we can interface to a digital input in order to save money, since digital inputs are much cheaper than analog inputs.

I have not found much at all, partly because I'm not sure what search terms to use.

I've found a few options from Phoenix Contact that are almost cheap enough, and have seen some fancier options from other manufacturers but these are much too expensive.

 

[itsmoked]

You may find after all the klutzing around that the analog input is cheaper.

Phoenix Contact is the typical place to go for what you're looking for.

You may also find an in-the-panel knob to be less expected and an operational issue. Any chance you can ditch the whole analog thing and put a cheap magnetic switch somewhere to detect The Point as operationally everyone can "see" what's set and how it's expected to work.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[danw2]

They're called DC alarm modules, sold as I/O modules, like the one below.

I think Keith is right, that multiple input AI's are probably less expensive than multiple DC alarm modules, unless the Chinese are making 15USD versions.

 

[RyreInc]

Thanks for the replies. In case anyone comes across this thread in the future, Wago and Murr Electronik also have solutions for these, all around $100-130 or so. And all are more expensive than an analog input, at least once you need ~3 or more.

 

[itsmoked]

Hi RyreInc.

Just today I found out my favorite supplier carries these. I was trying to remember where someone needed them. Your comment today was timely.

Analog_Input,_Relay_Output

And, they come with free 2-day shipping.

Keith Cress
kcress -

http://www.flaminsystems.com