At start up the
controller goes immediately to BØ and extends to maximum.
2
Controller can rest in
either BØ or DØ.
PHASE OPERATION
PHASE CHANGE PRIORITY
CURRENTPHASE
PRIORITY
COMMENTS
AØ
1. BØ
Unconditional
(i.e. Controller must go to BØ after AØ)
1. CTO Phase
Controller will go BØ ® CTO phase immediately, provided
BØ minimum has expired.
BØ
2. CØ
If the controller is going BØ ® CØ then BØ must extend to at
least the maximum extension green.
3. AØ
Controller will go BØ ® AØ immediately, provided BØ
minimum has expired.
CØ
1. DØ
Unconditional (i.e. Controller
must go to DØ after CØ)
1. CTO Phase
Controller will go DØ ® CTO phase immediately, provided
DØ minimum has expired.
DØ
2. AØ
If the controller is going DØ ®AØ then DØ must extend to at
least the maximum extension green.
3. CØ
Controller will go DØ ® CØ immediately, provided DØ
minimum has expired.
CTO Phase
AØ or CØ (Dependent on previous
operating phase before CTO phase)
·
If the previous phase (before going to the CTO
phase) was BØ, then the controller must go to CØ.
·
If the
previous phase (before going to the CTO phase) was DØ, then the controller
must go to AØ.
CONTROL TAKE OVER PHASE (B PHASE)
The CONTROL TAKE OVER (CTO) PHASE (i.e. BØ) is controlled by a 2
position switch in the Telstra Hatch of controller (If provided). This switch
is connected to Detector No.3.
The operation of the switch is summarized in the table below:
SWITCH POSITION
DETECTOR 3
POSITION
OPERATION
ON
SHORT CIRCUIT
CTO phase is
demanded and extended for as long as the switch is in the ON position
OFF
NORMAL
Normal
operation
OPERATION WHEN CTO PHASE IS DEMANDED
For each phase, the following table describes the priority for
servicing any demanded phases:
If the controller is in AØ when the CTO phase is demanded AØ is
first allowed to gap out or extend to maximum before going to the CTO phase.
(Note. The controller actually goes through BØ to get to the CTO phase).
If the controller is in CØ when the CTO phase is demanded CØ is
first allowed to gap out or extend to maximum before going to the CTO phase.
(Note. The controller actually goes through DØ to get to the CTO phase).
If the controller is in BØ when the CTO phase is demandedthen remain in BØ (which becomes the CTO
phase)
If the controller is in DØ when the CTO phase is demandedthen DØ is allowed to run its minimumbefore going to CTO phase
The CTO phase operates for at least the time specified in Special
Purpose Timesetting No.13.
DETECTOR OPERATION
Detector
4
Detector 4 position
OPERATION
SHORT CIRCUIT
A permanent
demand is placed for AØ and CØ.
NORMAL
Normal Operation
CALCULATION OF BØ AND DØ ALL RED TIMES
BØ and DØ are the ‘all red’ phases which are used to clear traffic
across the bridge after a vehicle phase.
The clearance time required: 131metre/11.11m/sec (40km/hr) = 11.79
(say 12).
BØ and DØ minimum green = Clearance time - AØ or CØ all red - BØ
or DØ yellow.
= 12-2-3 = 7 seconds.
OPERATION DURING FLEXILINK PLANS
During the period that Flexilink plans operate, substitute Special
Purpose Timesetting for AØ and CØ maximum extension green as outlined in the
table below: