I dont think FC 17 is implemented in the underlying Modbus library (jsmodbus) - well it isnt stated as NOT being supported but there is this issue that speaks of adding FC 17 (the item remains unchecked)
So, your options are:
- Raise a "Feature Request" on the github repos + cross your finger
- Create Pull Requests to both jsmodbus and node-red-contrib-modbus to add FC 17 support
- Fork both jsmodbus and node-red-contrib-modbus to add FC 17 support and start using it / publish own package.
- DIY the protocol in Node-RED.
DIY* It is not that complicated. The CRC calcs are well documented (there are even examples on this forum)
If you want a starting point, I wrote a simple demo you could build upon.
To aid you in this, there is an online modbus decoder. Here it is decoding the data in the github repo you linked:
