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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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strange code received by ESP32 #328

Closed marcovilla118 closed 6 months ago

marcovilla118 commented 10 months ago

Hi,

I tried to run esp32 as modbus slave.

MASTER send:

01 03 00 00 00 0A C5 CD

SLAVE (esp32 with basic RTU sketch) send back:

7F 7E FF FF EB 75 19

This is really strange and I tried to modify the slave address and other parameter but with no success. Do you have any idea about this code, thanks!!!

marcovilla118 commented 10 months ago

here the part of the code:

define RX 36

define TX 37

define SLAVE_ID 1

//#define MODBUSRTU_REDE ModbusRTU mb;

void setup() { Serial.begin(9600,SERIAL_8N1,RX,TX);

after some tests I found that changing the PIN number (rx, tx) doesn't change the output. So it looks like the hardware pin I have assigned are not used by the software.

I don't have idea where the problem can be.

emelianov commented 7 months ago

https://github.com/emelianov/modbus-esp8266/blob/master/documentation/README.md#modbusrtu