Modbus settings
Modbus TCP and RTU
- Modbus TCP is used for communication over LAN - functions FC: 1, 2, 3, 4, 5, 6, 15, 16
- Modbus RTU is used for communication over RS485 - functions FC: 3, 6, 16
Modbus register map
Modbus register map structure
- Each Modbus register consists of 2 bytes (16 bits).
- Ensure that values are written to and read from the least significant byte to avoid data misalignment.
- Only the least significant byte (LSB) is used to store values.
0 - bits 0-7: relay outputs 1-8 1 - bits 16-19: relay outputs 9-12 2 - bits 32-39: digital outputs HSS 1-4, LSS 1-4 3 - LSB: HSS PWM value 1 (0-255) 4 - LSB: HSS PWM value 2 (0-255) 5 - LSB: HSS PWM value 3 (0-255) 6 - LSB: HSS PWM value 4 (0-255) 7 - LSB: LSS PWM value 1 (0-255) 8 - LSB: LSS PWM value 2 (0-255) 9 - LSB: LSS PWM value 3 (0-255) 10 - LSB: LSS PWM value 4 (0-255) 11 - LSB: analog output 1 12 - LSB: analog output 2 13 - bits 208-215: digital inputs 1-8 14 - bits 216-223: digital inputs 9-16 15 - bits 224-231: digital inputs 17-24 16 - LSB: analog input 1 0-1023 17 - LSB: analog input 2 0-1023 18 - bit 288: reset (bit 0) 19 - LSB: 1st DS2438 Temp (value multiplied by 100) 20 - LSB: 1st DS2438 Vad (value multiplied by 100) 21 - LSB: 1st DS2438 Vsens (value multiplied by 100) - 46 - LSB: DS2438 values (up to 10 sensors) 47-57: DS18B20 Temperature (up to 10 sensors) (value multiplied by 100)
Loxone Modbus TCP settings
Insert new Modbus server and set IP and port "502" in the Modbus server settings
Create new Modbus device - and set/leave the address "1" of the Modbus client (Railduino module)
Loxone Modbus RTU settings
In the Modbus extension settings set the baudrate "115200", stop bits "1" and parity "none"
Create new Modbus device and set/leave the address "1" of the Modbus client (Railduino module)
