EM-18 is a nine pin device. Among nine pins, 2 pins are not connected, so we basically have to consider seven terminals.
|Should be connected to positive of power source.
|Should be connected to ground.
|Should be connected to BUZZER
|SEL=1 then o/p =RS232
|DATA is given out through TX of RS232
|WEIGAND interface DATA HIGH pin
|WEIGAND interface DATA LOW pin