Siemens SIPROTEC 7SJ62 Instruction Manual page 140

Configuration
Synchronization
Offset
Annunciation Due
to Missing Syn-
chronization
Changing the Syn-
chronization Mode
Operating Messag-
es from the Timing
System
Time Format
5-46
With IRIG B, the year must be set manually, because this standard does not include
a year value. Note : If a year number less than "91" is selected by mistake, the year
"91" will be set upon first synchronization.
For synchronization using pulses via a binary input, the present device time will ad-
vance to 00 seconds of the next minute for values greater than 30 seconds when the
positive slope of the pulse arrives. For second values less than 30, the device time will
be set to 00 seconds of the current minute. Because this signal is not monitored, each
pulse has a direct effect on the internal clock.
The "Synchronization Offset" (2IIVHW) setting allows correlation of the time signal re-
ceived from the radio clock to local time (time zone). The maximum settable offset is
± 23 h 59 min = ±1439 min.
The tolerance time ((UURU 7LPH / )DXOW LQGLFDWLRQ DIWHU) for time synchroni-
zation fault indicates how long cyclical synchronization may be absent until an alarm
is given.
External or internal synchronization normally occurs every minute. (An exception is
synchronization using a pulse via binary inputs because the signals may arrive several
minutes apart.) The setting for the tolerance time must, therefore, always be at least
two minutes. Under poor radio clock reception conditions, the user may delay the trig-
ger of the "fault" status condition even longer.
When changing synchronization mode, the hardware will re-synchronize to the new
source within one second. This causes breakdown of cyclical synchronization, and the
internal clock will be disrupted — as at startup — until the new synchronization source
takes over.
After modification to the synchronization offset in the time signal/operating mode, or
when changing year in IRIG B, the cyclical synchronization is not lost, but there is a
jump. To call attention to this, the time value causing a jump is reported with "7LPH
LQWHUUXSWLRQ 21" — without the synchronization offset, and subsequently with
"7LPH LQWHUUXSWLRQ 2))" — with the synchronization offset.
After the "7LPH LQWHUUXSWLRQ 21" message, the user must take into account that
the clock will jump. This message is issued under the following circumstances:
− If a synchronization interruption lasts longer than the monitoring interval mentioned
above, or as mentioned above, if the operating mode is changed;
− If a time jump is anticipated. The time value of the message is shown without the
jump.
The message "7LPH LQWHUUXSWLRQ 2))" is triggered:
− When the synchronization is re-established (e.g., after a break in reception by the
radio clock);
− Directly after a time jump. The time value of the message contains the time differ-
ential caused by the jump, in contrast to the previous "7LPH LQWHUUXSWLRQ 21"
message, thus allowing determination of the jump interval.
The time display may be set using either the European format (DD.MM.YY) or the US
format (MM/DD/YY).
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7SJ62 Manual
C53000-G1140-C121-1