Specifications
ST900 Family General Handbook
667/HB/32900/000 Issue 11 Page 139 of 265
Note that the demand confirm bit for the pedestrian stage on a stand-alone stream is
usually named ‘WI’ and returns the state of the wait indicator, see section 15.3.6.
15.3.5 Hold Pedestrian Stream Vehicle (PV)
The ‘PV’ control bit is used on a stand-alone pedestrian stream to hold the vehicle
stage at right of way. See section 27.3 for the description of the similar ‘PV1’ local
link input.
When the ‘PV’ control bit is de-activated, the UTC Inhibit Extension window time is
started. During this window period, even if the ‘PV’ bit is subsequently activated, the
controller will inhibit vehicle extensions and will move to the pedestrian stage if
there is a pedestrian demand is present. The UTC Inhibit Extension window time
can be viewed and modified using the UIE handset command.
15.3.6 Pedestrian Stream Confirms (GX, PC, WI, PR)
To meet UK requirements, the following UTC reply bits should be used on a stand-
alone pedestrian stream:
GX
- Open circuit when the vehicle is at right of way
PC
- Open circuit when the pedestrian is at right of way
WI
- Open circuit when the wait indicator is illuminated
PR
- Open circuit during the Puffin clearance period (see CMX in 6.11)
Unlike other reply bits, the above are required to be closed circuit when the signals
or the controller is switched off, see section 15.2.
The ‘GX’ and ‘PC’ confirm bits can be configured as normal stage confirm bits (see
section 15.3.2) but instead of being named ‘G1’ and ‘G2’ are named ‘GX’ and ‘PC’
(assuming stage 1 is the vehicle stage and stage 2 is the pedestrian stage). The
condition ‘no lamp power’ should still be configured to affect the ‘G’-bits, but in order
to meet UK requirements, the first two stage bits for a stand-alone stream are not
set by the firmware; both reply bits are de-activated.
15.3.7 Switch Facility (SF1 and SF2)
An ‘SF’ control bit may be programmed to simulate any one of the facilities provided
by the Event Timetable.
15.3.8 Switch Facility Confirm (SC1 and SC2)
An ‘SC’ reply bit may be returned to indicate that its associated ‘SF’ control bit has
introduced its facility of the Event Timetable.