Reserve State - Siemens ST950 Handbook

Timetable
Holiday clock
Time is preserved during power breaks of up to 48 hours by capacitors fitted to the
CPU board. Preservation of up to 30 days can be achieved by fitting an optional coin-
cell.
Both daylight saving time and time zones are catered for with the details adjustable
through the web interface.
Time can be synchronised to a number of sources including:
NTP
GPS
Mains supply
50 R
ESERVE
Reserve State is a secure state entered by the controller during times when it is
necessary to restart the high level application software e.g. during firmware update.
The Reserve State settings define whether the signals extinguish, flash amber or cycle
in fixed time. A time limit can also be configured so for example, the signals of a
pedestrian crossing can be held at vehicle green / pedestrian red for a period of time
while the application software restarts, but if it does not return because of a fault, the
signals can be extinguished.
There are limitations during Reserve State. Because the application software is
unavailable during the Reserve State, the controller has no access to external I/O. This
includes user interfaces, vehicle detection, pedestrian pushbuttons, UTC control and
monitoring, etc. These are all facilities that are controlled by the application software
and can be updated by the firmware or configuration update.
51 G A
REEN
A green arrow phase controls vehicle movements via a single aspect green arrow. It is
normally associated with a three-aspect Red-Amber-Green phase. The appearance of
these two phases needs to be carefully considered.
Where the round green aspect of three-aspect Red-Amber-Green signal is replaced by
a green arrow, it is not normally associated with a second phase. The phase operates
as a normal three-aspect phase so these phases are not considered 'green arrow'
phases.
52 I
NTERGREEN
An Intergreen Delay allows the intergreen between a phase losing right of way (ROW)
and one or more phases gaining ROW to be extended. Other facilities (e.g. RLM) may
Security classification
Version
Last Editor
Document Name
Copyright © Siemens plc 2015. All Rights Reserved.
S
TATE
RROWS
D
ELAYS
Unrestricted
4
Paul Cox
ST950 General Handbook
Mobility Division, Traffic Solutions
Sopers Lane, Poole, Dorset, BH17 7ER
Page 99 of 107
Status Issued
Date 16-Jul-2015
Document No. 667/HB/46000/000
Mobility is a division of Siemens Plc