
48900 INTERLOCK CONTROLLER USER MANUAL 1.10.0
Rev 11/19/2021 Page 9 of 16
PROPPED DOOR TIMER
The Door Propped timer, when enabled, begins counting down as soon as any door is open. If the door is
open when the timer expires, the door alarm output relay energizes. Use the rotary control to set the time
delay to any value between 15 seconds to 5 minutes.
EMERGENCY UNLOCK TIMER
The Interlock timer, when enabled, begins timing when the Emergency Unlock input is activated. All doors
remain unlocked and automatic doors remain enabled or open (see page 8) until the timer expires. Set to
any value between 30 seconds and 10 minutes. Emergency unlock overrides System Pause and unlocks all
doors. Door/lock lights go green.
UNLOCK PAUSE TIMER
This is typically used when a momentary REX device is located some distance from the door. The timer
allows the user time to get to the door and open it after making a request for access. The Pause timer,
when enabled, determines the time a locked door remains unlocked after a valid request by access control,
a pushbutton, motion detector or similar device. This only applies to doors that are set as normally locked.
Use the rotary control to adjust the unlock time between 2 and 30 seconds.
DOOR STATUS OUTPUTS (S)
Door Status relays are energized when the associated door is closed. Contacts are dry.
INPUT STATUS INDICATORS (C)
When an input is grounded the input is active, indicated by a lighted LED. The inputs for the 48900
programmable controller are opto-isolated for protection against interference.
Door Position Switches, Magnetic Bond Sensors and similar devices communicate door status - when the
door is closed the switch contacts are closed.
When a door is closed the red input LED for the door will be lighted. This makes it easy to verify interlock
operation and to troubleshoot a new installation. When the door opens, the LED should turn off.
For other REX devices such as Bio-sensors, card readers, motion detectors, pushbuttons, pneumatic
switches and the like, the green input LED should be on when the REX is active.
LOCK RELAY STATUS INDICATOR LED (J)
LEDs indicate that an output relay is energized. With the output set for FAIL SECURE, the relay energizes
to unlock or enable the door. Set for FAIL SAFE the relay energizes to lock or disable the door. Make
connections accordingly.
For verifying desired operation, compare lighted inputs to the lighted relay indicators.