STC SmartScanIS, User Manual

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14 January 2021, SmartScanIS User’s Guide for Union Pacific, EUD-2016026-00 Rev.2
Under normal circumstances, four axles must pass over the gating transducers for the system
to consider the event a valid train. This prevents maintenance equipment from generating
alarms and causing unwanted voice messages on the road channel. An exception occurs
when a catastrophic transducer failure combines with an auxiliary alarm. If the detector,
before recording four axles, records more than ten spikes from a gating transducer and
detects an auxiliary alarm, it records a train of less than four axles. The detector treats these
trains like any other, making all of the applicable announcements, storing them in long-term
storage, and transmitting them to Harriman.
10.2 System Deactivation
System deactivation is the process used to detect the moment that the train exits the site.
This happens in one of two ways, which is dependent upon whether the track circuit or one of
the transducers has activated the system.
If the track circuit activated the system, the system waits for the track-circuit signal to be
absent for ten seconds before deactivating. Likewise, if a transducer activated the system, the
system waits for ten seconds of inactivity from the gating transducers before deactivating.
10.3 Speed Calculation
A train's arrival speed and its exit speed are calculated. The exit speed is the speed shown on
generated reports. Union Pacific's Central Reporting System uses the arrival and exit speeds.
The arrival speed is calculated based on the on times of the first eight axles. The exit speed is
calculated based on the on times of the last eight axles. Calculated speeds over 99 mph
(159 kph) are reported as 99 mph. If a train has fewer than eight axles, its speed is reported
as 0 mph.
A train is called "slow" if its exit speed is 6 mph (9.7 kph). It is called "very slow" if its exit
speed is less than 6 mph. Trains having an exit speed of 6 mph (9.7 kph) or less generate an
Integrity Failure announcement. They also display an Integrity Failure message and either a
"Slow Train" or a "Very Slow Train" message, under the System Alarms heading on the Train
Detail and Exception Detail reports. However, if a Dragging-Equipment alarm is detected on a
Slow or Very Slow train, no Integrity Failure announcement is made, and neither the "Slow
Train" nor "Very Slow Train" message appears under the System Alarms heading. Messages
generated by any additional Integrity Failures found on such a train will still appear in the
System Alarms section of the report header.