Download ST950 FACILITIES HANDBOOK

Mobility Division, Traffic Solutions
Sopers Lane, Poole, Dorset, BH17 7ER
The timing range is 0 to 255 seconds in 1-second steps with one time for the whole
controller.
9.5.9
Conditioning Timers (PIR, CDT)
Up to 480 conditioning timers (numbered 0 to 479) are available for use as auxiliary
timers.
The uses of the conditioning timers include the following:
Holding a stage for a specified fixed period when no phases gain ROW, e.g. the
all-red stage. Normally dummy phases are used for this purpose, but this
method may be used if no dummy phases are available.
Timing long periods - can be achieved by running the same timer several times,
e.g. to time 20 minutes, give the timer a value of 20 and run it 60 times.
Switched window timers.
Limit Green watchdog timer.
Hurry Call watchdog timer.
The timing range for each timer can be configured as either 0 to 255 seconds in 1second steps or 0.0 to 31.8 in 0.2 second steps.
NOTE: 480 timers requires ST950 software version 46059 issue 5 or later. Prior to this,
only 96 timers were supported.
9.5.10 Limit Green Watchdog
(Facility constructed in Special Conditioning for Non UK Only)
In all modes except Hurry Call, Vehicle Actuated and Manual Control, the maximum
duration of each stage green can be governed by a limit green watchdog time. One
limit green watchdog timer (a Special Conditioning timer) is provided, which is applied
to each stage in turn.
The stage limit green watchdog timer commences timing when the stage green is
reached and is reset on a plan change, a mode change and when the stage
terminates.
If the limit green override code is sent from the ATC computer during computer stage
control mode, the limit green watchdog timer is held reset.
In the event of a limit green watchdog timer timing out before its associated phase
green has terminated, the controller will then revert to the next highest priority mode
configured for which a request exists and the fault will be logged. If the current mode at
the time of failure is fixed time mode, the controller switches off the power to the lamps.
Security classification
Unrestricted
Version
4
Last Editor
Paul Cox
Document Name
ST950 Facilities Handbook
Copyright © Siemens plc 2015. All Rights Reserved.
Page
56 of 303
Status
Issued
Date
16-Jul-2015
Document No.
667/HB/46000/001
Mobility is a division of Siemens Plc