Communication-Signal transmission -1.5kM - Better option

I am looking for a method which transmit OPEN/CLOSE signal from "A" Pump Station to "B" Pump Station.

(a) There is no wire connection between two Pump Stations, 1.5km apart.
(b) Ordinary wireless device is prohibited to use.
(c) Mobile telephones work at both Pump Stations.
(d) Internet service is not available at both Pump Stations, but probably set up newly if required.

Thank you!

We use these:

https://www.churchill-controls.co.uk/

Not a particular fan of the solution, but like you I can't run an optical fiber between points.
They seem fairly flexible too, and I believe 1.5km is achievable with the right antenna.

Is there a PLC or RTU capable of communications at both ends? If so, using a radio modem to set up communications is one option. For 1.5km you might be able to use the Schneider Trio JR900 series licence free model, depends on local obstructions and radio spectrum licensing in your country.

If thats a bit over kill, take a look at Elpro wireless I/O

Selk said:

Ordinary wireless device is prohibited to use.!

Click to expand...

Define "ordinary" Is wireless prohibited all together or just certain types?