Overview

The Local Door Alarm Tailgate with bounce back sensors or active reflective door frame mounted pedestrian counting
sensor (TG-L-BB) monitors persons walking through a controlled door or hallway and an access control card
reader system to ensure that only authorized persons pass through that secured area. The advance sensor
technology uses only one housing and requires no alignment which simplifies the installation process.
The TG-L-BB will generate an alarm if a person walks through the secured door or hallway without an access
granted signal from the card reader system.
The system provides a lock output relay. This feature requires only one output for each card reader from the access
control system to grant access to the tailgate system and unlock the door.

Features:

- Doorway mounted active reflective directional sensor (bounce back sensors)
- Lock Output Relay
- Card In / Free Exit or Card Out operation
- Optional Local Warning Alarm
- Optional Door Held Alarm
- Optional Forced Door Alarm
- Optional System Bypass
- Tailgate Alarm or Count Violation Alarm Relay Output
- Display includes Access Granted and Secure LED’s and Sounder
- Available with industry standard proximity card reader mounted on display plate

Operation
ENTRY GRANTED - A person presents a valid card to the entry reader at the door, and the access control system
provides a normally open 1 second momentary ENTRY GRANTED relay to the TG-LDA control board to signal that
access is granted.

EXIT GRANTED - If the system is card in and card out operation, then a valid card must be presented at the exit
reader at the door and a separate momentary relay for EXIT GRANTED from the access control system is required.

FREE EXIT – If the system is card in and free exit operation, then no exit granted signal is necessary from the
access control system and persons may exit through the sensing area without causing an alarm.

CARD STACKING - The TG-LDA board counts the number of access granted signals that are received from the
access control system and will allow that number of persons to pass through the sensing area without causing an
alarm.

LOCK OUTPUT RELAY - When an access granted signal is received from the access control system, the TG-LDA
board activates the lock output relay to unlock the door. The lock power supply should be separate from the tailgate
system power supply.

DOOR MONITORING - The TG-LDA board monitors the status of the door using an isolated normally closed door
contact. If the access control system is required to also monitor the door, then a double pole double throw door
contact is necessary.

PEDESTRIAN COUNTING - When the door is opened, then the TG-LDA board counts the number of persons
entering or exiting through the active reflective door frame mounted sensor area, and matches that count with the
number of access granted signals received from the access control system.

TAILGATE ALARM - If a person walks through the doorway without an access granted signal, then the TG-LDA
generates a TAILGATE ALARM. The local sounder activates so that the alarm is annunciated at the door. The
normally closed alarm relay opens. The alarm is reset after about 4 seconds.

OPTIONAL FORCED DOOR ALARM – If the door is opened without an access granted signal, then a FORCED
DOOR ALARM happens. The sounder is turned on and the alarm relay activates. The alarm is reset when the door
is closed.

OPTIONAL DOOR PROP ALARM – If a door is left open for longer than 20 seconds after a valid entry or exit, then
the LOCAL WARNING ALARM happens. The sounder beeps to warn persons in the immediate area that the door
is open. If the door is left open for longer than 20 seconds after the warning alarm starts, then the DOOR PROP
ALARM happens. The sounder is turned on and the alarm relay activates. The alarm is reset when the door is
closed.

OPTIONAL SYSTEM BYPASS - A normally open system bypass input is available. Closing this input will bypass
the tailgate and door alarms.

ALARM OUTPUT RELAY – The normally closed alarm output relay opens when a TAILGATE ALARM or DOOR
ALARM happens.

Technical Specifications

1 normally open momentary (1 sec max) exit access granted relay from access control system.

Required only for card in / card out systems. Not required for card in / free exit system.

1 normally open maintained system bypass.

Active reflective door frame mounted pedestrian counting sensor

Alarm automatic reset fixed at 4 seconds. System resets 4 seconds after a count or tailgate alarm
is detected.

Optional Door Held Open Warning fixed at 20 seconds. System will generate local warning alarm
if door is held open for 20 seconds after the last valid passage is detected.

Optional Door Held Open Alarm fixed at 20 seconds. System will generate a door held alarm if
door is held open 20 seconds past the start of the warning delay.

LDA circuit board is mounted next to the card reader interface module, either in a makeup
box or in the equipment room where the card reader system is located.

Sounder and LED Trim Plate may be mounted at the door mullion, 1 gang box near the
door, or in the ceiling above the door.

Door Frame Mounted Sensor Housing – 4” tall x 2” wide x 2” deep

Sensing area – single door or double door.

Display plate – single gang electrical box.

Display plate with integrated industry standard proximity card reader – double gang electrical
box