techem radio 3 - how to read a techem radio 3/vario 3 water meter by radio?

Hello,
i am fresh from installing new radio read water meters.
Up until now I've been entering everything into a table for myself manually (yes, I keep an excel of my water meter readings ), however it would be silly not to take advantage of the potential of radio read water meters. I just have no idea how to tap into the signal. I don't know if the reading is on demand or if the signal is spread every so often? is it bluetooth or some other protocol? what frequency?


techem radio 3/vario water meter - anyone know anything??? how to get to the signal?

I am refreshing the topic because I am also interested in this issue

It is secret knowledge and there is nothing strange about it, but what I have learned....

The controller, which goes with the meter reading instrument, sends a radio signal to the radio module of the water meter and this sends data with the status of the meter in response. There is a fair sized lozenge battery built into the module (about 15-20mm in diameter and about 8-10mm in thickness) I don't know what frequency the device operates at, but judging by the size of the antenna in the module (I have such an "old" module) I can guess that it will be about 1-2GHz. Commands can be sent by various protocols so without knowing the protocol it will not be easy to access the module's memory. You would need a spectrum analyser and controller instrument as well as a water meter module to get anything going.

When replacing a radio water meter, the old radio module is deactivated by the fitter (at close range with an infrared device to the diode in the module) and he activates the new water meter in the same way.

Off topic...
As you can read from the specifications of this water meter (publicly available pdf) "recognition of interference by a permanent magnetic field" so I warn possible savers otherwise....

I'm digging a bit but I think I know the solution:
Repo: https://github.com/weetmuts/wmbusmeters supports protocols:
- Techem MK Radio 3 and 4 (mkradio3,mkradio4) (non-standard protocols)

All you need is a simple rtl-sdr some software and that's it. I read my Multical 21 meter this way.