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Spectracom Format 4

Format 4 provides a format indicator, time synchronization status character, modified Julian date, time reflecting UTC with 0.1 millisecond resolution and a leap second indicator. Format 4 data structure is shown below:




FFFF Format Identifier (0004)
I Time Sync Status (Space, ?, *)
MJDXX Modified Julian Date
^ Space separator
HH Hours (00-23 UTC time)
MM Minutes (00-59)
SS.SSSS Seconds (00.0000-60.0000)
L Leap Second Indicator (space, L)
CR Carriage Return
LF Line Feed

The start bit of the first character marks the on-time point of the data stream.

The time synchronization status character (I) is defined as described below:

? When the receiver is unable to track any satellites and the time synchronization lamp is red.
* When the receiver time is derived from the battery backed clock or set manually through the Setup Port Interface.

The leap second indicator (L) is defined as:

(Space) When a leap second correction is not scheduled for the end of the month.
L When a leap second correction is scheduled for the end of the month.


0004 50085 124536.1942 L

The example data stream provides the following information:

Data format 4
Sync Status Time synchronized to GNSS.
Modified Julian Date 50085
Time 12:45:36.1942 UTC
Leap Second A leap second is scheduled at the end of the month.