The power supply of this product is wide voltage (3.0V ~ 30V), 3.3V system and 5.0V system compatible, 3.3V and 5.0V signals can match. This product with a terminal block and silicone wire, direct wiring use, all imported original chip, powerful, protection design, anti-interference ability, industrial, quality assurance 1 year! This transmission module to achieve the TTL signal and RS485 signal interchange, but we must know, 485 is half duplex communication, this communication can achieve two-way communication, but not in both directions at the same time, must Alternately; that is, each section of the communication channel can be either a transmitting end or a receiving end, but at the same time, the information can have only one transmission direction. To achieve the RS485 signal automatic flow control, send and receive direction automatically switch, use this module with your operation as simple as the serial portBaud rate: 110 ~ 256000bps