Item Type: Relay Board_x005f_x000D_ Module Control Terminal: 19-Wire interface, all interfaces have wiring terminals, which is convenient for users to wire_x005f_x000D_ 1. DC+: External DC Power Supply Positive (5V, 12V and 24V Modules Available)_x005f_x000D_ 2. DC-: External DC Power Supply Negative_x005f_x000D_ 3. XM: Common Terminal of Photoelectric Isolation Chip_x005f_x000D_ If high level control is adopted: this signal should be connected to the negative pole of the power supply of the user control board_x005f_x000D_ If low level control is used: this signal should be connected to the positive pole of the user control board power supply_x005f_x000D_ 4. X1-X16: Relay Control Interface,_x005f_x000D_ If XM is connected to the negative pole of the power supply: when this port is high (relative to XM), the corresponding relay is closed_x005f_x000D_ If XM is connected to the positive pole of the power supply: when this port is low (relative to XM), the corresponding relay is closed_x005f_x000D_ Relay Output Terminal: 48-Wire interface, all interfaces have wiring terminals, which is convenient for users to connect_x005f_x000D_ 1. NO1--NO16: The relay normally open interface, the relay is suspended before being closed, and it is short-connected to COM after being closed._x005f_x000D_ 2. COM1--COM16: Relay Common Interface_x005f_x000D_ 3. NC1--NC16: Normally closed interface of the relay, the relay is short-connected with COM before the pull-in, and it is suspended after the pull-in.