ST950S Plus+ Installation and Commissioning Manual
The IC4 defaults for Reserve State have not been changed for Plus+ Controllers, so:
•
Junctions with RLM configured to extinguish streams (typically part-time junctions) are still
extinguished by default
•
Stand-alone pedestrian crossings are initially held at vehicle green / pedestrian red but then
extinguish if Reserve State remains active for more than 4 minutes.
The designer can of course modify the Reserve State options, such as configure a stand-alone
pedestrian crossing to cycle continuously regardless of demands.
For more information on Reserve State, refer to the ST950 Facilities Handbook 667/HB/46000/001.
2.4.2. Red Lamp Monitoring
On Plus+ Controller, the IC4 options to latch RLM faults are disabled, e.g. “RLF2 only cleared by
RFL=1”.
The Plus+ Controller may trigger RLM faults during some power and/or communications scenarios. It
has been designed so it shouldn't do this during 'normal' power breaks. However, if some Reds Signals/
Nodes are temporarily missing, the Controller takes the configured RLM actions, so RLM faults are
triggered. But by avoiding the latching, it allows those faults to clear automatically and the signals to
resume normal operations should those Nodes/Signals reappear.
2.4.3. Lost Nodes and Suspended Mode
Plus+ Controllers monitor the Plus+ network for Lost Nodes, that is Nodes which are specified in the
Site Layout but cannot be found on the network. If a Node is lost for four weeks, then the Controller
is put into Suspended Mode and the 48V power is switched off, removing the energy that could under
fault conditions illuminate a signal on a Lost Node. In Suspended Mode all the signals are switched off.
In the period between the detection of the Lost Node and entering Suspended Mode the Controller
raises a fault or discrepancy which describes the problem with the Node. The Controller also raises a
fault indicating that there are Lost Nodes. If the Engineer restores contact with the Node, then the faults
and discrepancies will clear.
Details of the Lost Nodes can be found on the Lost Nodes web page, this identifies the Lost Nodes
and indicates when their 4-week timeout will expire. The web page allows the Lost Node timeouts to be
extended or disabled. As the Suspended Mode timeout is a safety measure it should only be disabled
after the Node has been physically disconnected from the Plus+ network.
Note:
Smartloops will be registered as a missing node on the Lost Node web page. However, as
Smartloops do not include traffic signals, they will not trigger the 'lost-node' timeout.
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