DSP-50 User Manual
Page 14 of 27
DSP50_MAN_A
Figure 4: Outputs with Extension
Normal Sensitivity / Sensitivity Boost (DIP Switch 4)
The detector has a user selectable feature that increases the sensitivity of the detector after initial detection.
This feature is most often used to allow a detector to have a lower starting sensitivity and then increase it after a
vehicle has been detected. This is useful in situations where high-bed tractor-trailer vehicles will be passing over
the loop. With this feature the detector may be able to detect the high-bed portion of the vehicle without
having to be overly sensitive and susceptible to false detections. NOTE: If detection of high-bed tractor-trailers
is required, correctly sized loops must be used.
DIP
Switch 4
Sensitivity Boost
OFF
Disabled
ON
Enabled
Factory Default
Fail-Safe / Fail-Secure (DIP Switch 3)
On the DSP-50, the option for fail-safe or fail-secure only applies to Output A. In general, a fail-safe detector will
activate the output when the loop circuit is failed. This is useful on a safety loop to prevent accidental closure of
a gate on a vehicle. On the free exit loop this will keep the gate open until the situation is fixed. Fail-safe is used
in applications where it is important to allow traffic flow to continue. A fail-secure detector will not activate the
output 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.
Output B is always fail-secure when not in the fail output mode.
These failure modes only apply to the output when external power is applied. That is, the failure output is more
of a loop failure output than a total failure output. When placed in the fail-safe position, Output A will be
activated when the detector recognizes that the loop is somehow compromised, like if a loop wire is
