Stanalone access controller support 1000 users build-in EM,Mifare one proximity metal standalone Stanalone access control system controller 1. Product SpecificationItem specificationpowerDC12V+ ... , exit button, bell, door sensor, alarm3. the LED and Buzzer3.1Normal working status3.1.1. Valid command: short beep ... 2 + TT; TT stands for the delay time, such as door open time is 3 seconds, then TT=035.9 ...