Hi @TrystanLea ,
Could you provide any guidance on how I might diagnose the connection. I have discussed the problem at length with the Sontex distributor but I am getting no further forward.
Brian
@Brain1000 I spent many hours trying to get data from my 531 and never got further than “no reply received”. So just following along here to see if there are any new ideas.
Hello @Brain1000 @knightian. Sorry for not getting back to you sooner on this.
@paul_tanner also had trouble reading from the Sontex 531 using our MBUS reader and in the end went for a different brand that seemed to work without any issue. Paul suggested the issue may be due to the voltage produced by our MBUS reader being too low.
I have a Sontex 531 myself and it’s working fine and I tested another 3 of our MBUS readers this morning and they all worked fine as well. I’ve got a relatively short run of cable to the MBUS meter, it may be that the voltage drop across that is low enough. My Sontex is mains powered and I thought that was a factor but now Im not sure if that’s right.
Glyn has been testing another MBUS reader that has a better hardware design and we’ve decided to swap over to these instead of continuing to produce our own. We’d be happy to send out a couple of these new readers to see if that solves the issue for both of you. I will check with Glyn when we can get these for you.
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I’ve just ordered more of these new MBUS readers and put them in the shop:
I’m afraid there’s a 30 day lead time to get more stock of these new readers.
Please could you send the shop a support email so can get a pre-order placed for one of these new readers: [email protected]
Hi Trystan,
It’s good that this is a minority issue.
I’d be happy to test your alternative solution and return it afterwards.
I can’t really say why I went for the battery-powered Sontex. That
may have been a bad idea.
Best/ Paul
Quoting Trystan Lea via OpenEnergyMonitor Community
[email protected]:
@TrystanLea Many thanks from me too. My cable was quite long, so I tried shortening to just 10cm and unfortunately still nothing.
I’d be happy to try the new reader - perhaps I could exchange it for the two existing ones I’ve tried? I’ll message the support email. 
Did you mange to resolve this? We’ve now got stock of the mbus readers:
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Nothing wrong with battery powered Sontex,. When connected to M-bus reader the power for the meter is supplied via M-BUS so battery life is not an issue. Battery is just used for backup.
@glyn.hudson @TrystanLea
Hi, Many thanks for the new M-BUS reader. I have fitted it and it worked immediately. Many thanks for the great assistance.
Best regards,
Brian
(M-BUS corrected)
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Could we please be consistent and use the correct abbreviation on the Shop and Guide.
It is M-Bus not MBUS - both are used which will end up causing confusion
Yes, we should try and be more consistent. I’ve corrected a few strays on the shop.
Even though I know the difference between them, I always get muddled between Modbus and M-Bus.
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Hi Trystan,
Many thx for this. Sontex Page3 is just what I need (pun intended).
I was hoping to grab the command from your code bu noticed the link is now broken.
/Paul
That was an older tool for an arduino based MBUS reader and is not compatible with the more recent RaspberryPi implementation. That specific tool has moved to: https://github.com/openenergymonitor/HeatpumpMonitor/tree/master/HeatpumpMonitorTH/Firmware/Arduino/MBUS_Reader.
@paul_tanner Here is the section of the emonhub MBUS code that sets the pages for the Sontex emonhub/src/interfacers/EmonHubMBUSInterfacer.py at master · openenergymonitor/emonhub · GitHub
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