1. RS485 communication interface: A+, B- are connected to the 485+, 485- interfaces of the inverter respectively 2. DC8-36VKF128 terminal power supply port: 8-36V, GND are connected to the 24V, GND interfaces of the inverter respectively 3. SIM card slot: supports the installation of IoT traffic cards or ordinary mobile phone cards, supports full network access, the metal side of the card is facing down during installation and pay attention to the direction of the card notch 4. Type-C USB 5V power supply interface: KF128 terminal power supply and USB power supply can be selected either 5. IPEX antenna interface: It is recommended to use an antenna with a gain of about 5DBI SMA antenna interface: You can choose either IPEX or SMA antenna. SMA antenna is suitable for occasions where an external antenna is required. It is recommended to use an antenna with a gain of about 8DBI Color: As shown Material: plastic Package Contents: 1 x frequency converter board