LED Indicators: The green Power LED blinks once per second to indicate the detector is operating and powered.  The red Detect LED will turn on when a vehicle is over the loop detection area.

Loop or Wire Failures: In the case of a loop circuit failure, the green LED flashes slowly (twice per second) for anopen loop circuit failure.  The green LED will flash fast (10 times per second) to indicate a shorted loop circuit.

Fail Safe vs Fail Secure: A fail safe detector will output “detect” when the loop circuit is failed.  This is always useful on a safety loop.  On the free exit loop this will keep the gate open until the situation is fixed.  This is useful in applications where it is important to allow traffic glow to continue.  A fail secure detector will never output “detect” when the loop circuit is failed.  This will keep the gate closed.  This is useful in high-security areas or installations where containment is needed.  The DSP-7 is a fail safe detector.  Note:  Never use a fail secure detector on a safety loop.

Connector: Removable 7-pin terminal block.
Pin assignments shown below (from left to right).
1: Relay Normally Closed (NC) – contact opens for detect
2: Relay Common
3: Relay Normally Open (NO) – contact closes for detect
4: Power common
5: Power in (10 to 30 Volts AC or +DC)
6: Loop
7: Loop

Size: Height: 1.52″    Width: 2.9″    Depth: 1.56”