Troubleshooting RS485 communication on the 4 pin COM port

Created by Roberto Hernandez, Modified on Wed, Jan 15 at 5:37 AM by Roberto Hernandez

This port is a green port located externally on all Solis inverters on the bottom of the inverter.

Pin 1 = +5 volts DC

pin 2 = -5 volts DC

Pin 3= +RS485

Pin 4 = -RS485

Checking the voltage on pins 1 and 2 with a multimeter will ensure power is provided to the communication device (ex: wifi datalogger. The voltage reading should be 5V on DC.

Checking the voltage on pins 3 and 4 with a multimeter will ensure RS485 signal between the inverter and the communication device. RS-485 voltage should read ~1.7Volts on DC