newb here. feasibility of detection of two-wire dry contact alarm?

I am totally new to this so please bear with me.

I have a piece of equipment at work that has an audible alarm and alarm port. From what I understand, it's a standard, two-wire dry contact that is OPEN when the audible alarm is off (no alarms or silenced alarms) and CLOSED whenever the audible alarm is activated. It does not have voltage i can detect in either state (alarm or not) I confirmed the system closes when the alarm is on by measuring the resistance using the ohm meter.

My question is: would it be possible to detect the alarm, and via wifi relay the alarm notification thru text, email, tweet?

My very limited understanding of arduino says...maybe.

This is how i think it might be done using an arduino uno, wifishield and voltage sensor module I'd have to do something like this: 1 have some low voltage applied to the alarm port 2 monitor voltage using one of those voltage sensor module 3 if circuit closes (alarm), the voltage increase is detected 4 if voltage increases: have a command send a message thru wifi to email address, tweet....

Is this more or less how it could be done? or is this a completely wrong approach?

I have been reading a lot, but have not come up with a real answer yet.



Attach one lead from the dry contact to an arduino pin configured as INPUT_PULLUP. Attach the other lead from the dry contact to Arduino ground. When the alarm is off, the Arduino input will read HIGH. When the alarm is on the input pin will be pulled LOW. The current draw is very low when the alarm switch is closed. The coding is similar to all the common push button sketches.

Indeed, sounds like it's basically just a button in an odd shape. Treat it as such. Look for how to handle a push button and you'll find lots of examples on how to deal with them.