starze / nilan_communication_bringup

Nilan (R) modbus communication bringup

That project is supposed to provide software for basic communication with nilan heatpumps, containing the cts-602 control board.

Software PreRequirements

pytho packages: pyserial, minimalmodbus

installation with pip: pip install pyserial minimalmodbus

Hardware PreRequiremnts

An RS485 to USB dongle, because Nilan is using modbus on top of the physical RS485 layer.

Connection description

HAZARD NOTE: If you dont know how to carefully deal with electricity stop here. High voltage danger! No warranties.

The cts-602 is inside the heatpump, and the correct connectors are on the lower left corner on the circuit board (see picture). The pins on the RS485 connector have the following order:

Pin 1 12 VDC output Pin 2 COM1- RS 485 A - Modbus Pin 3 COM1 - RS 485 B - Modbus Pin 4 COM2 - RS 485 A - User panel Pin 5 COM2 - RS 485 B - User panel Pin 6 Ground As you would find it in the MOD-BUS-CTS602-GB.pdf manual.

For the modbus connection you need the pins 2,3,6. In the picture pins two and three are not connected.