Great thanks. I have worked out that if you don’t use “write multiple holding registers” you get very strange results. Either nothing, or the value not updating.
After writing as directed in the manual, I seem to be getting [near] real time data from the flow sensor.
The manual states “If there are multiple functions to add, they must be written all at once using command 16 (Write multiple holding registers)”
I saw in your code [EmonHubMinimalModbusInterfacer.py]. You only write 3, and there is a 0.5 second gap between writes. You may want to write all 8 using command 16 and see if the reliability of the flow sensor readings improves.
I will run for 24 hours and compare with the flow sensor in the pump. My quick tests showed that when I changed the pump speed the reported flow rate changed. Readings below are at 10 second intervals as I dropped my pump from 100% to 90% power.
|[87]: |265|
|[87]: |265|
|[87]: |261|
|[87]: |261|
|[87]: |261|
|[87]: |261|
|[87]: |234|
|[87]: |234|
|[87]: |234|