Mirx wireless relay boards through metal buildings


I want to use these boards to control an engine driven pump from a tractor that will be in various fields.

My furthest distance is about 4000 feet with clear line of sight, but in some fields, I’m closer at 2500 feet but will have one or two metal clad buildings blocking line of sight.

Will this work and what kind of antenna (Omni directional obviously) should I look for?




It is hard to say with certainty because of the nature of RF, I don’t think it will reliably go through one or two metal buildings over a distance of 2500 feet with the included antenna.

An aftermarket high-gain 900 MHz antenna may work for this, but I don’t have one I could recommend for that particular environment.


Assuming the metal building has electrical service, how about installing a XBee repeater with an external antenna above the roof line ?


Unfortunately that series does not support the mesh protocols native to S3B.


Thanks for the replies.

That’s unfortunate that it may or may not work. Is there a repeater available that would work with these boards?
If there is no repeater, is there a better option? I’d like to have 6 inputs and outputs at each end, minimum is 5 inputs in the tractor with 5 outputs at the pump. Minimum the other way is one input at the pump with an output in the tractor.
The most important feature is a fail safe state if communication is lost for some reason. I plan to build some relay logic to slow the pump down and close the discharge valve. That’s what I like about the MirX products; the relays turn off after 30 seconds of no comms.


Any thoughts? The boards are pretty expensive if they’re not going to work!


Hi Paul,

Sorry for the late response.

There isn’t a repeater option available for this particular series.

Its quite possible that it will work in this environment. My experience is just saying that I can’t guarantee it.

Your best bet to get it to work with the given environment is to use a high gain antenna for the 900 MHz frequency. I would recommend contacting Digi for a recommendation on this as we use their modules for the wireless protocols. Specifically the S3B @900MHz module family which they’ll probably ask.

If all else fails, we have a 30 day money back return policy: https://ncd.io/info/warranty-return-policy/ second paragraph.