What are the supported Modbus function codes of the M171 HVAC controller?

Search FAQs

Issue:
M171 supported Modbus function codes

Product Line:
M171, EcoStruxure Machine Expert HVAC

Resolution:
Below is the list of supported Modbus function codes of Modicon M171’s Modbus RTU master
- Read Coils – Function 01 (0x01): reads one or more 1-bit read-write objects;
- Read Discrete Inputs – Function 02 (0x02): reads one or more 1-bit read-only objects;
- Read Holding Registers – Function 03 (0x03): reads one or more 16-bit read-write objects;
- Read Input Registers – Function 04 (0x04): reads one or more 16-bit read-only objects;
- Write Single Coil – Function 05 (0x05): writes a single 1-bit read-write object;
- Write Single Register – Function 06 (0x06): writes a single 16-bit read-write object;
- Write Multiple Coils – Function 15 (0x0F): writes one or more 1-bit read-write objects;
- Write Multiple Registers – Function 16 (0x10): writes one or more 16-bit readwrite objects