Simplemodbus -

void loop() { modbus_update(); // listens and replies to Modbus requests } #include <SimpleModbusMaster.h> unsigned int readRegs[10]; unsigned int writeRegs[10];

void setup() { modbus_configure(9600, SERIAL_8N1, 1, 2, 3); // master has no slave ID } simplemodbus

void setup() { // Modbus slave ID = 1, RS485 (or serial) on pins 2,3 (DE/RE) modbus_configure(9600, SERIAL_8N1, 1, 2, 3, holdingRegs, 10); } void loop() { modbus_update(); // listens and replies

void loop() { modbus_update(); // master uses this to send pending requests void loop() { modbus_update()