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emelianov / modbus-esp8266

Most complete Modbus library for Arduino. A library that allows your Arduino board to communicate via Modbus protocol, acting as a master, slave or both. Supports network transport (Modbus TCP) and Serial line/RS-485 (Modbus RTU). Supports Modbus TCP Security for ESP8266/ESP32.
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modbusRTU issues #347

Closed janniebunny closed 6 months ago

janniebunny commented 6 months ago

Hi there, I have been using serial and ESP32 IP modbus for this library for years. Now nothing works. I am not an expert, simply a maker. How is it possible that it is somehow better when I have tried everything to make it work? It is really frustrating. I am not a power user and simply want to communicate with my hardware the way I used. No fancy stuff. I find it near impossible to even try and find the issue.

All I want to do is setup registers and read/write them.

If I use serial, I use USB-serial, no TxRx pins.

Can anyone show me a sketch for Serial modbus WITHOUT tranmission pins? Thank you.

Regards Jan

emelianov commented 6 months ago

USB-Serial should be used with Serial-RS485 modules with auto RX/TX switching.