UTC System Handbook - Siemens

System Handbook for an STC UTC System 666/HE/16940/000
In most cases, each controller, whether junction or pedestrian, is associated with
one node. However, the System does allow more than one controller to be
associated with a node. This is particularly useful when the controllers are close
together.
7.12 SCOOT Translation Plans
SCOOT translation plans define the relationship between the SCOOT stages and
fixed time stages for each controller on the node. These plans are prepared as part
of System data preparation.
Normally a 3 stage controller has three SCOOT stages with a one to one stage
correspondence between UTC and SCOOT. The System allows for up to 2 (or 8 -
see section 2.3) stages to be demand dependent in a similar manner to fixed time
control. If a fixed period is required for a particular stage, such as a car park exit,
then this stage may be combined with another stage to create one SCOOT stage.
This "2 UTC stage" SCOOT stage then appears on-street as a fixed period UTC
stage plus a variable period UTC stage and the 4 UTC stage controller appears to
SCOOT as having 3 stages. This approach does require careful calculation of the
start and end delay for each associated SCOOT link.
In some circumstances it is desirable to operate two or more controllers as one
SCOOT node, typically where they are too close together to have loops on the
internal links. The System achieves this by allowing a controller to be associated
with a sub-set of the SCOOT stages and other controllers to be associated with the
rest of the stages. In this manner all controllers referencing a SCOOT stage make
the required moves at the same time. Using the fixed period mentioned above
allows fixed offsets to be introduced between controllers in "multi-equipment"
nodes.
7.13 Plan Compliance Faults
7.13.1 Introduction
The Plan Compliance fault detection facility is designed to allow the operation of
both intersection and pedestrian controllers to be monitored. Checks are made
against the various controller timings stored in the System data and any departures
reported as faults. The controllers are also monitored to check that they obey the
control commands sent out by the System.
Plan compliance checking is inhibited for 4 minutes after a new mode of control
is requested at a site. This gives the controller time to respond to the new control
algorithm (i.e. get in step).
If a fault is detected the fault log is updated, a message sent to the System Log
and the equipment isolated. The System has a command that allows this isolation
to be inhibited. The System may be configured (S) such that, if isolation is
inhibited, only the first occurrence of a plan compliance fault is reported or all
xsuch occurrences are reported.
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