EM-18 is a nine pin device. Among nine pins, 2 pins are not connected, so we basically have to consider seven terminals.
|VCC||Should be connected to positive of power source.|
|GND||Should be connected to ground.|
|BUZZ||Should be connected to BUZZER|
|SEL||SEL=1 then o/p =RS232
|TX||DATA is given out through TX of RS232|
|DATA1||WEIGAND interface DATA HIGH pin|
|DATA0||WEIGAND interface DATA LOW pin|