Open source windows software for logging data from electricity meter (rs485 modbus)

New here, and wanted some pointers on setting up monitoring/data logging system for my electricity meter (rs485 output) and my windows 10 laptop… Just want the basic data (kwh usage throughout the days/weeks) to be sent to my pc for easy analysis. Is there any recommended free software out there to help me do this?


The biggest issue will be getting a definition of the data protocol for the RS485 interface. Do you have that?

I have found the modbus registers map for my meter: Eastron (SDM630) data logging. MODBUS registers map.

is this what you mean?

Here’s a link that should help you find something you can use:

Do you have an RS-485 interface for your laptop?

I use this interface

as well as this one
with good results.

There are several posts on the forum that deal with reading an Eastron SDM 220.
That should help get you started.
(Search the forum for eastron)


I have one of the USB adapters @Bill.Thomson pointed to (from China IIRC) plugged into an OrangePi talking to a MHRV via a Python script. Assuming you don’t want your laptop tied to a plugged in adapter hardwired into your meter, you might be better looking at a Pi based solution possibly via Node-Red and pass the data to EmonCMS via HTTP or MQTT.

Absolutely and a link to get you started Read the SDM220 modbus with the minimalmodbus python module. :grin:

I also found a node-red flow although this is for an SDM120

Thanks, hadn’t found that site, added to favorites…
Got one of these coming snail mail from china:

(only one i could find with windows 10 in title…)

cool, thanks for link…
Actually was planning on tying up the old laptop to this one job. Not quite ready to dive into raspberry pi and learning python, although it does seem pretty cool… its a time thing for me at the moment.