Hello
I’m a beginner with openhab2 and would like to integrate my Techem meter for heating, hot- and cold-water. All three have a M-Bus interface which allows Techem to measure my usage remotely. Is there an openhab2 binding which supports this M-Bus?
Has anyone experience with integrating these meters?
Thank you very much for your help.
Manuel
Hi Manuel,
I have no experience with the Techem devices and as far as i know there is no native M-Bus Binding existing currently.
Anyways you could check if there is a Gateway that fits your needs and translates to a protocol openHAB can understand.
For example Wachendorff is offering several M-Bus Gateway solutions.
Ethernet, MQTT or BACNet translation are only a few examples.
Always worth to mention with m-bus is “Relay”, who ware offering hardware and diagnostic software like mbsheet to have a direct look on the m-bus.
Maybe you can also find some information about the topic an adfweb.com.
(I think Wachendorf is the main distributor for adfweb in germany.)
What i found with a quicksearch is https://www.packom.net/ who seem to offer a head for raspbery pi.
This may be a low cost solution but needs some work and effort from your side.
I had some experiences with Wachendorff/ADFWeb Hardware in the past an the device configuration is straight forward after getting some knowledge about the envioronment and topology
Hello Jerome
Thank you very much for your detailed answer. Unfortunately this seems to be not very easy. Is there a chance to have a M-Bus binding some day? Are there any intentsions?
Either way I have to check with Techem first because all M-Bus wires are sealed for security reason so the customer can’t manipulate the meters. What a cheek! This are my data.
Greetings Manuel
I can’t tell you much about this.
If yomeone who is able to program it has the need and puts in some effort, there wil be some.
I have seen some libs for mbus durig a quick search, but the main effert seems to be getting the hardware connected and talking to openHAB.
Hello Jerome
Thank you very much for your answer. I think Techem just made it impossible anyway for me because they won’t give me access to the M-Bus interfaces. In my installation at home all meters are sealed with lead and I won’t break them up. Otherwise Techem will make me responsible for the whole M-Bus in the building block if I break something.
Of course they have an own Smart Metering solution which they are trying to sell to the customers. I would prefer to have my data on my openhabianpi and not somewhere in the cloud.
Greetings Manuel
There is a wireless m-bus binding which you can check out New Binding: Wireless M-Bus / Techem heat cost allocators 
Based on the story from above thread you can find that Techem uses its own coding and in case of radio frames simply reports one big binary blob. Normal devices report measurements in separate fields according to european norm (heat usage, flow temperature etc)
The “security reason” argument they have is one thing, however lack of information from them how to get permitted to read such a thing is other.
For my own setup I’ve chosen different manufacturer which is aligned with standards.
I have a plan (among many others) to work on m-bus integration, however my chronic lack time is a blocker. I already have rs232/mbus master adapter and heat meter with m-bus output and hope to get it covered at some point of next year…
The bright side - depending on your technical abilities - the jmbus lib used in wm-bus binding supports also serial communication and it is compatible with m-bus as well. Thus adopting the binding should be possible.
Thre is a M-Bus Raspberry Pi HAT M-BUS RPI HAT - Zihatec GmbH
probably this should be an way to connect up to 6 units
is there a library for gateways?
btw. this m-bus master M-Bus Master Hat – The Original and Best – packom.net supports 3 units
Hello @Martin_N, welcome in the topic! 
I haven’t looked for mbus equipment beyond USB adapter from relay (which I confirmed to work). I attempted once to use RS232 to M-Bus adapter and I lost bunch of time (and money on it), since I was not able to get it working properly with any tool.
Anyhow - main point for M-Bus masters is power supply, because as far I remember, meters might be permitted to power themselves from the line. Effectively it puts constraints on how many devices you can have on the bus and also imply electronics design. I think 3-6 units is usually sufficient to cover most of single family buildings/apartments.
With regard to libraries - not sure what you mean by gateway. In context of M-Bus I’ve made an unofficial binding which acts as a master to meters and supply readout request within configured period. You can download KAR file from here: https://repository.connectorio.cloud/#browse/browse:co7io-public-snapshots:org%2Fconnectorio%2Faddons%2Forg.connectorio.addons.kar.mbus. There are some caveats to jmbus library and integration of serial ports.
If you have an equipment to test with - I recommend first playing with jmbus alone to see if it is able to gather data. Then, openHAB part, is just mapping of M-Bus registers to channels.
Cheers,
Łukasz
I read out an M-Bus (wired) subscriber as follows.
Hardware Raspberry Pi with USB M-Bus adapter, on the Pi is running software according to instructions from here:
I have created a generic MQTT Thing on openHAB:
UID: mqtt:topic:73089d4ec9:WatermeterMQTT
label: Watermeter MQTT
thingTypeUID: mqtt:topic
configuration: {}
bridgeUID: mqtt:broker:73089d4ec9
channels:
- id: Data
channelTypeUID: mqtt:string
label: Data
description: ""
configuration:
stateTopic: mbusmeters/360295669215FF16
With channels:
The data is then read from the items using JSONPath:
