Features: Support ASCII text and RTU dual protocol automatic identification, no user setting in required. The meter can display 4 digit of serial port. Wide range of power supply voltage between DC7~36V. Large 0.56inch display area for only 4 digit ,more clear. The baud rate can be 1200bps/2400bps/4800bps/9600bps/19200bps/38400bps/57600bps/119200bps. Specification: Display Digit:4 Display Size:0.56inch Display Color:Red Power Supply Voltage:DC 7~36V Current:30mA Wiring Diagram: V+ :Power positive GND: Negative power supply A: RS485 BUS A B: RS485 BUS B (note the wiring sequence, first connect the power cable to confirm the module works normally and then connect the communication line) Communication interface: non-isolated, 485 bus and GND terminal common ground. If there are multiple devices on the bus, be sure to connect the terminating resistor to the bus end device. Baud Rate: 1200bps/2400bps/4800bps/9600bps/19200bps/38400bps/57600bps/119200bps Size:79 x 43 x 21.5mm / 3.11 x 1.69 x 0.85in Installation Size:76 x 39.2mm / 2.99 x 1.54in Package List: 1 x Meter 1Support ASCII text and RTU dual protocol automatic identification, no user setting in required. 2Wide range of power supply voltage between DC7~36V. 3The meter can display 4 digit of serial port. 4Large 0.56inch display area for only 4 digit ,more clear. 5The baud rate can be 1200bps/2400bps/4800bps/9600bps/19200bps/38400bps/57600bps/119200bps.