DSP-10 User Manual
Page 9 of 26
DSP10_MAN_C
frequencies to operate within. If there are suspicions that one of the two loops are interacting, simply change
one of the two unit’s frequency settings.
DIP Switch
Frequency
9
10
OFF
OFF
High
OFF
ON
Medium High
ON
OFF
Medium Low
ON
ON
Low
Fail Memory (DIP Switch 8)
Normal operation is that during a loop failure, the green Power LED will indicate what type of loop failure (open,
short, or large ΔL/L). During the loop failure the red Detect LED and output A will be active for fail-safe
operation or inactive for fail-secure operation. If the loop recovers from its failure, the red and green LEDs,
along with its two relay outputs, will operate normally again. However, when Fail Memory is enabled, the green
LED will continue to indicate a previous failure by blinking 1850 milliseconds on, 50 milliseconds off, 50
milliseconds on again, and then 50 milliseconds off. This blinking sequence will repeat until a reset or power
cycle occurs. Note that the red LED and relay outputs will continue to work normally.
Extended Presence (DIP Switch 7)
Under normal conditions, the DSP-10 will hold a vehicle presence for a reasonable amount of time. If a vehicle
parks over the loop and the detector measures a 1% ΔL/L, it will slowly tune that vehicle out over a period of
about one hour. For those instances where a longer period is desired, extended presence will hold that same
vehicle for about 19 or 20 hours. This is quite a long time, but it isn’t infinite. The DSP-10 does not have infinite
presence.
Output B Selection (DIP Switches 5 and 6)
Output B can be programmed to operate in one of four different modes that are selected using DIP switches 5
and 6. The following table identifies these four modes:
DIP Switch
Output B Mode
of Operation
5
6
OFF
OFF
True Presence
OFF
ON
Pulse on Entry
ON
OFF
Pulse on Exit
ON
ON
Fail
True Presence:
The B output will be energized whenever a vehicle is present over the loop detection area. The
A output can be modified by the delay and/or extension timing settings. The B output will not use these timing
settings. For example, if 2 seconds of delay is set, output B will energize as soon as the vehicle is detected, while
output A will wait for two seconds of continuous presence prior to energizing.
Pulse on Entry:
Every time the loop is occupied, a single 250 milliseconds pulse will be output on the B output.