This is a very specific IoT module being used to communicate to solar power controllers branded EPever of EPsolar. The RS485 to Serial module is shown connected to a RJ45 plug with standard ethernet cabling colours.
The unit used here is a MAX485 based module which converts RS485 to serial. The MPPT controller connects over an RJ45 connection shown in the picture, with green as A+, white as B-, and black as common ground. The ground isn't essential but does help significantly with noise suppression.
The software only polls the solar power controller and receives back data on the status of battery, solar panels and load outputs, measuring input and output currents and voltages which is published to MQTT. The option to set parameters, including the time, or turn on the load, has not been implemented.
Below are reference materials associated with this interface