Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 11 Page 176 of 265
Plan 0 A B C Plan 1 A B C
(Required Offset) (35) (20) (0) (Required Offset) (0) (19) (46)
Group 0
(Main Road)
35 20 0
Group 0
(Main Road)
0 19
46
1
Group 1
(Side Road)
75
15
65
5
35
Group 1
(Side Road)
30 44
71
26
Cycle Time 60 60 60 Cycle Time 45 45 45
Note that where the original group time plus the required offset exceeds the cycle
time (see those entries that have a strikethrough
), the group time has to be manually
adjusted so that it always specifies a time within the cycle (see those entries in
italics).
21.7 CLF Parallel Stage Streaming Facilities
The controller has up to 16 plans but only one plan can be in operation on the whole
controller at a time.
CLF can run on all streams or on some streams if the others are running higher
priority modes, e.g. Hurry Call mode.
If CLF is disabled on a stream, or the plan does not affect any stages in that stream,
that stream will run a lower priority mode, e.g. VA or FT mode.
Within a plan, each group influence (see section 21.3) is only associated with one of
the controller’s streams, identified by the stage that the group influence is
configured to affect. When the time within the cycle arrives to start a new group, that
group only affects the stream in which the specified stage resides. The other
streams continue to run the previous group influences that affected those streams.
Therefore, each stream will be running a different group influence.
21.8 Quicker Plan Synchronisation
Certain contracts require that, when using the base time method of Plan Introduction
mentioned above, the controller must synchronise with the Plan quickly.
To achieve this, the following constraints are placed on the CLF facility:
1. The Stage movement restraints table used by CLF should not have purely
prohibited moves or ignore moves configured. They should either be allowed
moves or if this is not acceptable for safety reasons, alternative moves should be
specified. If alternatives are specified, it is preferable for the alternative stage to
be one or two stages ahead in cyclic order of the original target stage.
For example:
If the move 1-2 is not allowed
Then the alternative could be 1-3 or 1-4.