UTC System Handbook - Siemens

System Handbook for an STC UTC System 666/HE/16940/000
If the count of transmission errors exceeds 15 (U) in one hour an Intermittent
transmission fault is reported but equipment connected to the OTU is not isolated.
The fault will be automatically cleared if no more than 15 (U) transmission errors
have occurred in the hour since the last time that the one-hour intermittent fault
threshold was exceeded.
If more than 15 (U) errors occur within a 180 (U) second period, a Persistent
transmission fault will be raised and on-street equipment connected to that OTU
isolated. If no transmission errors occur within a continuous 180 (U) second
period the persistent transmission fault will be automatically cleared and the onstreet
equipment reconnected.
When either of the faults or clearances above occur, the fault log is updated and a
message sent to the System Log.
4.13 System Log
The System Log is a magnetic and paper record of activity on the System. It
records fault occurrences and clearances, control mode changes, operator
commands that affect on-street control and comment lines entered by the operator.
The paper log is output on the System Log Printer. If this goes faulty then a record
is kept of where in the log printing failed. When the printer is back on-line the
printing starts where it left off. Printing of the System Log may be disabled by an
operator command.
System messages are transferred from the TCCs to the main log on the TMC's
System disc. If the TMC is unavailable then data is held in the TCCs and sent to
the TMC when it comes back on-line. On a daily basis the day's log information is
"archived" to a separate file, the lifetime of this file being user configurable. Data
is archived from the System Log when the log is full and a warning message is
also given.
The contents of the System Log can be listed on any suitable terminal by operator
command. This command allows the data to be selected by SCN, fault category,
date and time period. The System Log can be down-loaded to a suitable PC
terminal - see section 10.2.
4.14 Extended Logging
Note: licensed facility - see section 2.3.
An optional facility is available that allows approximately six years' of log entries
to be stored and to be immediately accessible by an operator. This facility requires
an additional hard disc to be installed in the System's TMC.
4.15 System Re-Starts
The UTC System provides an optional facility which allows the SCOOT settings
of cycle time, stage lengths and offsets, which were in effect prior to a System
shut down to be re-instated after the System has re-started. The re-instatement of
SCOOT settings only occurs if the period betweeen System shut down and re-start
is short (less than 5 minutes).
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