Node Red - Modbus Custom FC

[Steve-Mcl]

I don't think any of the modbus nodes are developed to support custom function codes.

I have previously done a POC, custom parsing that could be modified to use the serial nodes and support any FC - it is after all just simple ASCII codes and checksums.

How to create an Modbus-TCP alarm status dashboard

Slight update: Added header checks - works quite nicely reading 350 registers... [image] [{"id":"f77e01bf.42f16","type":"inject","z":"5e6c8b.7f38b374","name":"FC4: Read 50 from address 100","props":[{"p":"topic","vt":"str"},{"p":"sid","v":"1","vt":"num"},{"p":"pid","v":"0","vt":"num"},{"p":"len","v":"6","vt":"num"},{"p":"uid","v":"1","vt":"num"},{"p":"fc","v":"4","vt":"num"},{"p":"address","v":"100","vt":"num"},{"p":"registerCount","v":"50","vt":"num"}],"repeat":"","crontab":"","once":false,"…