1、Increase the power supply anti‑reverse connection function, the wrong power supply will not damage the module; fault‑tolerant design, the control line is broken, the relay will not act. 2、Relay module uses genuine high‑quality relays, normally open interface load: AC /10A, DC 30V/10A. 3、Using high-quality small two-way isolated optocoupler, strong anti-interference ability, stable performance; trigger current only needs 5mA. 4、The user can select the control level of the relay, which can be high‑level or low‑level pull‑in. 5、Built-in current-limiting resistance, which can be directly controlled by the positive and negative poles of the power supply, or controlled by the /O port of the single-chip microcomputer. Item Type: Relay Board Module Control Terminal: 19-Wire interface, all interfaces have wiring terminals, which is convenient for users to wire 1. DC+: External DC Power Supply Positive (5V, 12V and 24V Modules Available) 2. DC-: External DC Power Supply Negative 3. XM: Common Terminal of Photoelectric Isolation Chip If high level control is adopted: this signal should be connected to the negative pole of the power supply of the user control board If low level control is used: this signal should be connected to the positive pole of the user control board power supply 4. X1-X16: Relay Control Interface, 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 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 Relay Output Terminal: 48-Wire interface, all interfaces have wiring terminals, which is convenient for users to connect 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. 2. COM1--COM16: Relay Common Interface 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. 1 x Module