I need to set up a Modbus RTU MASTER communication network and also SLAVE RTU with ESP8266 12E (or F, whatever), but I couldn't find a good Modbus RTU library. It has several pages / blogs / videos referring to the things of the PDA Control or the Trialcommand (which are the same library), but I could not make it work fine. The only one I could keep comunication was the PDA Control, but there were a lot of writing and reading errors, a lot of timeouts, etc., even setting the serial to work at 9600 instead of higher speeds.
Does anyone know of any library that works well for ESP8266? ...or some Modbus RTU routine that works (written in any language) and which I can use to "translate" to the C language used in Arduino?
I've tried using these libraries without success: