DSP-50 User Manual
Page 9 of 27
DSP50_MAN_A
All three LEDs will turn off for 500 milliseconds at the start of the reset event. After that, the Detect A and
Detect B LEDs will flash according to their fail-safe or fail-secure mode of operation. A flash rate that is the same
as the power LED indicates the output is operating as fail-safe. A much faster flash rate indicates that the output
is operating in the fail-secure mode.
Output A will be active if the detector is in the fail-safe mode. Output B is always fail-secure and will not
activate during a reset.
NOTE:
If a vehicle is over the loop during the reset period it will not be detected.
Presence Detection
Presence detection is only available in the loop mode of operation (DIP switch 8 OFF). If the detector is in the
magnetometer mode of operation only pulse on entry operation is available.
While in the loop mode of operation, Output A will always operate in the presence detection mode. Once
activated, the output will remain activated for as long as a vehicle is detected over the loop. After four minutes
of continuous detection, the detector will begin to slowly retune the detector with the goal of tuning out the
vehicle that stalled or parked on the loop over a relatively long time.
The time it takes to complete the retuning process is dependent on the strength of the call being induced by the
vehicle. In the Normal Presence mode usually takes between 15 minutes and about 4 hours. In the Extended
Presence mode the retune process may take over 24 hours. When the retuning process is complete, any loop
area that vehicles can still travel over will still detect the vehicle as expected. Once the vehicle leaves, the
detector will fully recover from the retuning process within 1 second.
Output B can be set to operate in the True Presence mode (not available in the magnetometer mode of
operation). In this mode Output B activates as soon as a vehicle enters the loop and drops as soon as the loop is
no longer occupied. The output will ignore any Delay or Extension features that are currently active.
Pulse Detection
When the magnetometer mode of operation is selected (DIP switch 8 ON), pulse on entry is the only detection
mode of operation and is applied to Output A and Output B. If the detector is in the loop mode of operation
pulse on entry and pulse on exit modes of operation are available.
In the loop mode of operation Output B can be configured for pulse on entry or pulse on exit operation. The
pulse generated by the output will be 250 milliseconds long. Output B will follow any Delay or Extension
features that are currently active. Pulse operation is not available on the A output except in the magnetometer
mode of operation.
In the magnetometer mode of operation Output A and Output B are always configured for pulse on entry
operation. The pulse generated by Output A can be modified using the extension feature. If no extension is
active the pulse will be 250 milliseconds long. If the 2-second extension feature is active the pulse will be 2
seconds long. If the 5-second extension feature is active the pulse will be 5 seconds long. The pulse generated
