IMSA Traffic Signal Technician 2
In a TS2 cabinet, how many times can the MMU experience a "Port 1 Fail" in a 24 hour
period before
the fault is latched? - answer1
On a 2070 MMU monitor unit, how does the field tech program allowable phases? -
answer Remove diode on program card for allowable phases
On an MMU, is it possible to tape the reset button to prevent the traffic signal from going
into flash? - answerYes, it by-passes the conflict feature and will not flash
On a NEMA CMU program card, how does the signal tech program allowable phases? -
answerInstall copper jumpers and soldering them on the program card
According to best maintenance practices, how often should CMU/MMU be tested? -
answerAnnually
The MMU indicates a RED-FAIL fault on phase 6. Why? - answerThe load switch/switch
pack produces no outputs.
The purpose of the controller CVM (Controller Voltage Monitor) output is to allow the
CMU/MMU to
monitor the - answerController health
When a Technician is recertifying the CMU/MMU at an intersection, what should the
technician do to have the intersection exit flash? - answerReplace the CMU/MMU with a
newly tested unit
Absence of all colors on a load switch will be indicated by what fault on an MMU or
MMU2? - answerRed Fail
Which of the following can be programmed on an MMU to latch after a fault occurs? -
answerField check
How often is an MMU's clock updated from the controller? - answerOnce a second
In a signal cabinet, on the signal monitor, what does a field check indicate? - answerThe
signal indications don't match the controller output for a phase
A NEMA CMU/MMU uses a program card to tell the monitor which phases are permitted
to run together. Which answer is CORRECT? - answerNEMA monitors have wire
, jumpers missing in all positions, the tech solders the ones in that allow phases to run
together.
When the controller timings DO NOT match the timing sheet, who should be contacted
for correct
times? - answerTraffic Engineer
An older TS1 cabinet experiences a flash condition but the signal heads are also
showing active green, yellow, and red indications. What is the MOST COMMON issue?
- answerThe mercury contactor is stuck in the normal position.
In a Dual-Ring, 8-phase traffic signal controller, how many phases can run in each ring
at the same
time? - answer1
Observations indicate that vehicles are being detected in one lane and that this is
shown on the detection interface unit. However, the controller does not show any
detection for that phase. This could be caused by - answerImproper detection phase
assignment programming in the controller
As soon as vehicles leave the detection zone of an approach that has met its minimum
green time, a signal immediately goes to yellow from the green display. This could be a
result of - answerno extension time programmed.
What is one reason the phase interval may change even though there is still vehicle
demand? - answermaximum green time has been met
A signal tech is reviewing the controller logs and continually sees a cycle fault error.
What does that
mean? - answerThe CU has not serviced a call in two cycles while in free mode.
A coordinated corridor is working well except at one intersection where a platoon of
vehicles is being stopped. The MOST LIKELY problem is the - answerclock has drifted
affecting the offset and needs adjusting
Observations indicate that right turning vehicles approach the intersection on the side
street, stop and then make a right turn on red. When this happens the signals cycle to
the side street even though there are no longer vehicles present in the detection zone.
This could be caused by - answerthe detection being set to locking detection
Of the following, which answer MOST LIKELY would require a controller database be
verified to be
correct? - answerWhen a controller upgrade has been performed
Which offset mode is the easiest way to view progression in a coordinated corridor? -
answerBeginning of green
In a TS2 cabinet, how many times can the MMU experience a "Port 1 Fail" in a 24 hour
period before
the fault is latched? - answer1
On a 2070 MMU monitor unit, how does the field tech program allowable phases? -
answer Remove diode on program card for allowable phases
On an MMU, is it possible to tape the reset button to prevent the traffic signal from going
into flash? - answerYes, it by-passes the conflict feature and will not flash
On a NEMA CMU program card, how does the signal tech program allowable phases? -
answerInstall copper jumpers and soldering them on the program card
According to best maintenance practices, how often should CMU/MMU be tested? -
answerAnnually
The MMU indicates a RED-FAIL fault on phase 6. Why? - answerThe load switch/switch
pack produces no outputs.
The purpose of the controller CVM (Controller Voltage Monitor) output is to allow the
CMU/MMU to
monitor the - answerController health
When a Technician is recertifying the CMU/MMU at an intersection, what should the
technician do to have the intersection exit flash? - answerReplace the CMU/MMU with a
newly tested unit
Absence of all colors on a load switch will be indicated by what fault on an MMU or
MMU2? - answerRed Fail
Which of the following can be programmed on an MMU to latch after a fault occurs? -
answerField check
How often is an MMU's clock updated from the controller? - answerOnce a second
In a signal cabinet, on the signal monitor, what does a field check indicate? - answerThe
signal indications don't match the controller output for a phase
A NEMA CMU/MMU uses a program card to tell the monitor which phases are permitted
to run together. Which answer is CORRECT? - answerNEMA monitors have wire
, jumpers missing in all positions, the tech solders the ones in that allow phases to run
together.
When the controller timings DO NOT match the timing sheet, who should be contacted
for correct
times? - answerTraffic Engineer
An older TS1 cabinet experiences a flash condition but the signal heads are also
showing active green, yellow, and red indications. What is the MOST COMMON issue?
- answerThe mercury contactor is stuck in the normal position.
In a Dual-Ring, 8-phase traffic signal controller, how many phases can run in each ring
at the same
time? - answer1
Observations indicate that vehicles are being detected in one lane and that this is
shown on the detection interface unit. However, the controller does not show any
detection for that phase. This could be caused by - answerImproper detection phase
assignment programming in the controller
As soon as vehicles leave the detection zone of an approach that has met its minimum
green time, a signal immediately goes to yellow from the green display. This could be a
result of - answerno extension time programmed.
What is one reason the phase interval may change even though there is still vehicle
demand? - answermaximum green time has been met
A signal tech is reviewing the controller logs and continually sees a cycle fault error.
What does that
mean? - answerThe CU has not serviced a call in two cycles while in free mode.
A coordinated corridor is working well except at one intersection where a platoon of
vehicles is being stopped. The MOST LIKELY problem is the - answerclock has drifted
affecting the offset and needs adjusting
Observations indicate that right turning vehicles approach the intersection on the side
street, stop and then make a right turn on red. When this happens the signals cycle to
the side street even though there are no longer vehicles present in the detection zone.
This could be caused by - answerthe detection being set to locking detection
Of the following, which answer MOST LIKELY would require a controller database be
verified to be
correct? - answerWhen a controller upgrade has been performed
Which offset mode is the easiest way to view progression in a coordinated corridor? -
answerBeginning of green
