Hello everyone,

I'm currently working on an electrolyser project and need to measure the power it consumes. We have a Sonnen WM271 power meter, which has an Ethernet port (marked as #9 in the attached photo). I’m trying to figure out if it’s possible to connect the power meter directly to my laptop via Ethernet for monitoring purposes.

Is it feasible to connect the meter directly to my laptop, or would I need an additional device or hardware to facilitate this? If it is possible, what kind of software would I need to properly monitor and record the data?

I’m quite new to this field, so any guidance or suggestions would be greatly appreciated.

Thank you in advance for your help!

here is the link of the full manual
https://www.sonnensupportaustralia....-_manual_-_power_meters_-_kd-401_en_22118.pdf

 

From the text on page 20 on using "a jumper between pins 6 and 8" for the last power meter, one can infer that the power meter uses Modbus RTU with an RS-485 electrical bus, not Ethernet.

The power meter would be a Modbus RTU slave.

A Windows Modbus Master/client (or an HMI program with a Modbus RTU driver) is used to talk to a Modbus slave/server.

It would be possible
- to use a USB/RS-485 converter (recommend an FTDI chipset) to talk over RS-485 to the power meter.
- to use an Ethernet/RS-485 gateway WITH MODBUS firmware to talk via Ethernet to the power meter. Generic Ethernet/RS-485 gateways have problems with the Modbus RTU timing, the gateway MUST state that it is for Modbus.

Most Windows Modbus Master/client software like Modscan, Open Modscan or Modpoll can use either a virtual serial port or Ethernet, depending on their configuration. I think Simply Modbus uses a separate app for serial or Ethernet.

It will be a challenge to figure out which registers to poll and what the number formatting is because that information is missing from the linked manual.