Eastron SDM120 energy meter

[PieterS]

My heatpump arrived! So I have to monitor that device too. Good experience with the Eastron SDM630 as 3-fase meter to load the electric vehicle. But the heatpump expects 2 single fase cables. One for the unit outside and one for the boilerheater (only legionella run )

So I am considering whether 2 times the SDM120 with Modbus in combination with Espeasy will also work as well. Does anyone have experience now?

And would it then be possible to read both devices on one bus with one MAX485

Thanks for your input!

Pieter

[TD-er]

Yep, you can run as many SDM devices on the same bus as you would like.
As long as each has its own unique modbus address. and are set to the same baud rate.
So you may want to set the address one-by-one to the meters and then hook them all up on the same modbus-bus.

Don't forget to terminate the last one with a 120 Ohm resistor if you're running longer cables.

I have a unit here with 3 meters.

Only limit is that you can read roughly 10 registers per second, so if you plan on adding several tasks per meter to read each upto 4 registers, you may limit yourself in the measurement interval per meter.

My setup here has a SDM220, SDM120 and T1100 (not Eastron)

[PieterS]

H Gijs,

Nice to read your information. Two sensors on 1 bus will work! That confirmation was what I needed. I do not need to know these kind of readings every second.

I will order them and will show the results of course.

Thanks for reply and best regards!

[PieterS]

A statusupdate about the two Eastron SDM120's in a bus along with Wemos board and ESPeasy.

This afternoon I found some time to configure one SDM120 with ID 2 and connect them together to the Wemos. All close together on DIN-rail with a DIN-rail 5V PSU.
And it works as expected.





No errors in the checksum and all values are there!

Next step was to build the rules to upload all values to Domoticz.

Code: Select all

On SDM120M_L2#All Do  // Receives 4 arguments, 1st one is already sent to the controller, so can be ignored
  Publish,domoticz/in,'{"command":"udevice","idx":2454,"nvalue":0,"svalue":"%eventvalue2%"}' // Current L2
  Publish,domoticz/in,'{"command":"udevice","idx":2457,"nvalue":0,"svalue":"%eventvalue3%"}'  //Power L2
//  Publish,domoticz/in,'{"command":"udevice","idx":2289,"nvalue":0,"svalue":"[var#5]"}'  //Total Active Power
Endon

On SDM120M_L3#All Do  // Receives 4 arguments, 1st one is already sent to the controller, so can be ignored
  Publish,domoticz/in,'{"command":"udevice","idx":2455,"nvalue":0,"svalue":"%eventvalue2%"}' // Current L3
  Publish,domoticz/in,'{"command":"udevice","idx":2456,"nvalue":0,"svalue":"%eventvalue3%""}'  //Power L3
//  Publish,domoticz/in,'{"command":"udevice","idx":2285,"nvalue":0,"svalue":"%eventvalue4%"}'  //Total Amps van 2 fases
Endon

Glad to see it works right away! Thanks a lot Gijs!!

[TD-er]

And soon you can also use formulas on that plugin (has been reported as a bug, will be fixed soon)

[bidrohini]

Hopefully the bug will be fixed soon.