Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 11 Page 185 of 265
With Selected Fixed Time to current maximums, when NORMAL mode is restored
there will still be demands present for all non-running phases, so no vehicles will be
trapped against a red signal.
23.3 Fixed Vehicle Period (FVP) Mode
The vehicle phase of a stand-alone pedestrian stream appears at green for at least
a fixed period. No vehicle detection equipment is required.
If the pedestrian phase is demanded while this period is still running, the vehicle
phase remains at green. When the period expires, the vehicle phase loses right of
way and the pedestrian phase subsequently appears at green.
If the pedestrian phase is demanded after this fixed vehicle period has expired, the
vehicle phase immediately (subject to the pedestrian demand delay see section
7.4.3) loses right of way and the pedestrian phase subsequently appears at green.
When the pedestrian phase has completed its green period and the controller has
executed the required ‘pedestrian to vehicle clearance period’ (see section 6.11),
the vehicle phase returns to green.
The fixed vehicle period is specified by the handset commands MEX, MFX, MGX
and MHX allowing four different times to be called up at different times of the week.
23.4 Fixed Time Parallel Stage Streaming Facilities
There are two options:
23.4.1 Independent Fixed Time
Each stream will have its own fixed sequence of stages, or will run to current
maximums and will move around it independently of the other streams.
23.4.2 Linked Fixed Time
Fixed time mode can be configured to provide Linking between stage combinations
in different streams as an alternative to ‘normal’ fixed time mode which forces moves
on each stream independently.
A maximum of 32 fixed time steps will be provided. Specified for each of these 32
times will be a configured stage combination.
When linked fixed time is introduced, the Controller will move to combination 0 and
time duration for combination 0 will start when all stages have appeared. When time
0 duration has expired, the controller will move to combination 1 and the time
duration for combination 1 will start when all stages have appeared. This process
will be repeated for each configured stage combination, until the last configured