Please Add SWAP function for Modbus RTUoverIP CRC

Feature Requests
1

I tried to connect my Marstek Venus Home battery trough modbus using rtuoverip.
The modbus request was created correctly by home assistant.
Request: 01037dc800011d98 Analysis with: Online Modbus RTU Parser & Modbus TCP Parser

Read1
Read1733×650 81.5 KB

The reply from the Marstek has the Data in the correct order but swaps the order of the CRC.
Marstek Modbus RTU Reply cannot be passed because of the swapped CRC: 01030208ccd1bf
This is indicated by the Rapid Scada Modbus parser.

Swap
Swap718×528 73.9 KB

When I manually correct the CRC the answer parses correctly:
Corrected
Corrected722×641 89.6 KB

In my search for the answer I see other problems related to Modbus CRC errors, some are probably related to the (reverse) order of the CRC.
Maybe it can be implemented like this?
fix

Kind Regards,
Hayo

2

Hi,
There has been a firmware update of the Marstek that resolves this issue.
Modbus is now working with HA.

3

What kind of data is available via modbus in Marstek? I’m thinking about purchasing one of Venus and trying to understand possible integration options. Do you have any link? cc @Superduper1969

4

Generic Marstec Venus Topic: https://gathering.tweakers.net/forum/list_messages/2262054

Marstek Venus Modbus Topic: https://gathering.tweakers.net/forum/list_messages/2282240

5

Woo-hoo! Nice stuff, thanks for sharing!
Everything is controllable without their app