Raw RS485/Modbus logs from SofarSolar and Growatt meters in Zero Export context?

[peufeu]

How can an address be 0? Shouldn't all these addresses be like 30001, 30002 etcetera.?

Register addresses start at 0
a bit of info about the protocol https://www.fernhillsoftware.com/help/drivers/modbus/modbus-protocol.html

 

[1Watt]

I've built an ESPhome SDM230 emulator but I don't have an inverter to test it on right now. It's working in so much as I can use a laptop to poll it with the requests from an inverter and it replies with ~valid results.

If anyone wants to give it a try and offer feedback I'd be grateful.

GitHub - That-Dude/esphome-fake-eastron-SDM230: ESPHome Modbus Server component to fake the Eastron SDM230 smart meter

ESPHome Modbus Server component to fake the Eastron SDM230 smart meter - GitHub - That-Dude/esphome-fake-eastron-SDM230: ESPHome Modbus Server component to fake the Eastron SDM230 smart meter

github.com

 

[1Watt]

How can an address be 0? Shouldn't all these addresses be like 30001, 30002 etcetera.?

Is there a website where I can enter like:
02 04 24 43 65 C3 A2 43 66 2F 1B 43 63 52 78 00 00 00 00 00 00 00 00 3E 67 71 5D 00 00 00 00 00 00 00 00 42 4B FC 43 18 CC
And it shows me all the data? I'm struggling with learning Modbus.
I know that 02 is the address of the slave and 04 is the read function, but other than that I'm a little confused :D

I've been using this to decode the packets

Online Modbus RTU Parser & Modbus TCP Parser

rapidscada.net

 

[NullByteZero]

OK I'm pleased that your mentioned the issue of too many writes to the EEPROM as I was planning to use this approach! I will try this anyway for a short time, just to see if it works.

I now have access to the inverter RS485 modbus using this project, I flashed a D1-Mini with the sketch, plugged it into the inverter's USB port and can read/write the registers successfully via MQTT, it works perfectly.

I will build a modbus interface for the export controller inputs and dump the registers, they may be very simple. Or did you do this already?

I have one other question. In the screenshot above it looks like you could enable register 122 option 3 "Enable CT clamp export limit" and directly attached a CT clamp to pins 5 and 6 to get realtime export control. But I'm not sure what the Growatt CT clamp specs are?

CT clamps can output voltage or ampage of different ranges. I wonder If we can directly control the input voltage to these pins and gain control over the export control by emulating the CT clamp.


View attachment 109025

If I'm not mistaken you could just set the register 02 to the value 0 (default) and settings of registers 3,4,5 would't save to flash/eeprom. ?

 

[niko23]

Hi guys, I might have solved the issue have a look here:
An SDM230 meter emulator with an ESP8266 that communicates with a Growatt inverter via RS-485 enabling power export limitation functions

https://github.com/alessandromatera/SDM230-emulator-growatt-esp-mqtt

 

[010011010010]

Hi guys, I might have solved the issue have a look here:
An SDM230 meter emulator with an ESP8266 that communicates with a Growatt inverter via RS-485 enabling power export limitation functions

https://github.com/alessandromatera/SDM230-emulator-growatt-esp-mqtt

Hi,

So, I want to try this with an sofar inverter - as this seems to send messages back regardless of IDs or ModBus protocol, will it work as is also with sofar?
Any risks involved (I only have superficial knowledge about rs485/modbus...)?

Thx!

 

[curto]

Hi,

So, I want to try this with an sofar inverter - as this seems to send messages back regardless of IDs or ModBus protocol, will it work as is also with sofar?
Any risks involved (I only have superficial knowledge about rs485/modbus...)?

Thx!

Did you try this ? I assume that you have a single phase Sofar as the Eastron 230 is a single phase meter only ?

Craig

 

[010011010010]

Did you try this ? I assume that you have a single phase Sofar as the Eastron 230 is a single phase meter only ?

Craig

Not yet. I was missing some parts. Now, I dont find time and motivation...

 

[jtdaling]

Hi!

I am looking into a possibility to limit the power output of a second inverter when power is not needed because I am not allowed to feed into the Grid.
Previously the option to control the power production via DRM was discussed.
Are DRM settings written on to the eeprom or can I update DRM settings as often as I wish without wearing out the inverter's memory?

John