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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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Slave timeout? #343

Closed RosiersRobin closed 6 months ago

RosiersRobin commented 8 months ago

Hi,

I'm trying to write a slave (client) device, but I seem to have some trouble...

Currently the simple Modbus client example (found here https://github.com/emelianov/modbus-esp8266/blob/master/examples/RTU/slave/slave.ino ) doesn't seem to work for me either? I keep getting "no response from slave".

This CAN be an hardware issue, but not really certain about it...

I'm using a macbook pro M3 with ModbusRtuMaster application.

Any help is appreciated!

emelianov commented 7 months ago

Most likely wiring problem. On esp's rs-485 transceiver side make sure you are using auto rx-tx type or re-de are properly connected. On Mac side check usb-ttl chip is fully supported.