Hi there i was going to redo my hydronic heating system this spring and I was wonder if anyone has used one of these before: did not cost much $50 on sale on aliexpress which if you add everything together is cheaper then me building the same [DSC05010] it has RS485 on it and I am a little uns…

so having failed with two dongles and a long-distance discussion with the meter vendor in China, they confirmed that the meter I had has not got modbus software installed in it. (eyerolls!) so I bought a Kamstrup 603 with Modbus and 230v mains modules. Works a treat! What do they say…’buy cheap, bu…

Another couple of links that may be of use. https://code.google.com/archive/p/iotsys/wikis/MBusConnector.wiki#M-Bus-Master_for_Raspberry_Pi https://openenergymonitor.org/forum-archive/node/1944.html

okay since I am lazy somedays – would you think this would work for communication they have the same chipset tss721– <a href="https://www.aliexpress.com/item/USB-to-MBUS-Slave-Module-Discrete-Component-Non-TSS721-Circuit-M-BUS-Bus-Monitor/32917153031.html?spm=2114.search0104.3.15.5ab84a5c6spYBF&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10130_10068_10547_319_317_10548_10696_453_10084_454_10083_10618_10139_10307_537_536_10902_10059_10884_10887_321_322_10103,searchweb201603_59,ppcSwitch_0&algo_expid=936b92ed-549e-4aaf-9b03-a076d27cddfe-2&algo_pvid=936b92ed-549e-4aaf-9b03-a076d27cddfe&transAbTest=ae803_4" class="onebox" target="_blank" rel="noopener nofollow ugc">https://www.aliexpress.com/item/USB-to-MBUS-Slave-Module-Discrete-Component-Non-TSS721-Circuit-M-BUS-Bus-Monitor/32917153031.html?spm=2114.search0104.3.15.5ab84a5c6spYBF&ws_ab_t…

I’m afraid my Mbus experience is almost non-existent, I wouldn’t know for sure. Hopefully someone else can jump in and advise you better.

no worries I will chance it - $19.00 total for 2week shipping… it not going to break the bank … now with the use of mbus I found the docs for chipset tss721a.pdf (261.2 KB) oops I see I had to order master and not a slave so I ordered the master as well for a couple dollars more

HI pb66, I am interested in your experience with the heat meter interface. I have a chinese model, exactly the same as the one pictured but it is a 4-wire RS485 interface but I can’t get any response from it. The documentation I was sent (in Chinese) does not exactly match my device. Do you have a…

Hello, is there any news on this topic? I bought the same heatmeter and a usb2MBUS master from Aliexpress. But I can’t get any communication between the two. I also don’t know if the Modbus master is working properly. I would be grateful for any help.

I used a modbus explorer with the following. I think the issue is the default address, mine was 34. Black – 0V Green – RS485 (B) Yellow – RS485 (A) Red - +5V Device ID = 34 9600 Baud 8N1 Read Holding Register (4x) Offset 1, length 28.

Hello, So how did you get on or anybody else? I have bought also an energy meter, supposedly Mbus and when I asked seller for info he sent Modbus then later Mbus, on the PCB it is marked Mbus and has the two wire connection red and white. I have tried communicating with the meter using a Mbus to US…

Hi there. Did you actually get the meter to respond in the end? I’ve bought a similar one and have spent most of the afternoon trying to get it to speak to me! The docs say slave 1, 2400, 8E1 but nada. Cheers Tim Robinson

Two things to look at: It’s not unknown for the two legs of the bus to be swapped. MBus and Modbus are different protocols, and they don’t talk to one another. I write that because this Topic discusses both.

Ultrasonic heatmeter and Modbus

Sustainable Energy

glyn.hudson (Glyn Hudson) 16 February 2026 19:22 31

For anyone still looking at this thread, I’ve just managed to read data via modbus from the zpmeter. Here’s the emonhub interface: