User's Manual

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Figure 2.12 – Click! 112/114 Menu
The rack cards are also fail safe. This means that when a sensor does not receive
communications from a sensor within 10 seconds the rack card outputs will all
active. Normally, a SmartSensor Matrix unit will send 10 contact closure messages
per second. In other words, the rack card will go into fail safe mode after 100
messages have gone undetected by the rack card. All the detection channel LEDs
on the faceplate will also light up when a rack card is in failsafe mode.
For additional information about Click! 112/114 rack cards consult Appendix D.
Once the Click! 112/114 rack cards are installed, you will need to make sure that
each detector rack channel is properly mapped to correct traffic phase in the traffic
controller. The general NEMA standard for 8-phase numbering is presented in
Figure 2.13. In practice, many intersections will not have 8 phases and in some
cases they may not even follow the NEMA convention. Check the plans in the traffic
signal cabinet to verify how the phases are numbered at each intersection.
Note
Detection call messages are sent by SmartSensor Matrix 10 times per second.
The latency from transmission by the sensor to actuation on the backplane of
the rack card is less than 3.5 milliseconds.