Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 11 Page 170 of 265
Functions 8 and 9 only apply to stand-alone pedestrian streams:
8. INHIBIT PEDESTRIAN - prevent the appearance of the pedestrian phase and
hold the vehicle phase at right of way. Specify any stage in the stream.
9. ALLOW PEDESTRIAN - allow the pedestrian phase to appear at right of way if
demanded. Specify any stage in the stream.
Each group influence function continues to affect the stream containing the specified
stage until the group time of a group influence that affects the same stream is
reached in the CLF cycle. Meanwhile, influences that affect other streams may be
actioned as their group times are reached. Also see section 21.7.
21.4 The Base Time CLF System
21.4.1 Base Time CLF Description
In the base-time CLF system, all plans are synchronised to a ‘base time’, regardless
of when the plan is requested to take effect on the controller.
Typically the base time would be configured as 2.00am every day. However, the
base time can be configured to include a date so that the CLF plans can be
synchronised to midnight on January 1
st
for example, either every year or for a
specified year, e.g. 1980.
Note that it is essential that all controllers that are required to run synchronised CLF
plans must be configured with the same base time.
Therefore, the base time can be expressed in three different ways:
XX/XX/XX HH:MM:SS, e.g. XX/XX/XX 02:00:00
The ‘base time’ is a particular time today, e.g. 2am today (or 2am yesterday if the
current time is before 2 o’clock in the morning).
DD/MM/XX HH:MM:SS, e.g. 01/01/XX 02:00:00
The ‘base time’ is a particular time on a particular date this year, e.g. 2am on
January 1st. If the current time is 1am on January 1st, the base time will be set to
January 1
st
last year.
DD/MM/YY HH:MM:SS, e.g. 01/01/80 00:00:00
The ‘base time’ is the specified time and date, e.g. midnight on January 1
st
1980.
Note that all years are assumed to be in the range 1970 to 2069.
The time of day in conjunction with the time switch settings determines which plan is
controlling the intersection under CLF mode.
When a new plan is requested to start, the plan does not necessarily start at the
beginning of its cycle time. Instead, the plan effectively resumes at the correct point
within its cycle time as though it had been running since starting at the base time.