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Spectracom Format 7

This format provides a time data stream with millisecond resolution. The Format 7 data stream consists of indicators for time synchronization status, leap second and Daylight Saving Time. Time data reflects UTC time and is in the 24-hour format. Format 7 data structure is shown below:

Note: Format 7 cannot be configured for a Time Zone Offset or with automatic Daylight Saving Time adjustment. Attempting to configure a Local clock using Data Format 7 with either a Time Zone Offset or automatic DST rule will result in an error message.

Example message:

CR LF I^YY^DDD^HH:MM:SS.SSSL^D CR LF

Where:

CR Carriage Return
LF Line Feed
I Time Sync Status (space, ?, *)
YY Year without century (99, 00, 01, etc.)
^ Space separator
DDD Day of Year (001-366)
HH Hours (00-23 UTC time)
: Colon separator
MM Minutes (00-59)
SS Seconds (00-60)
. Decimal Separator
SSS Milliseconds (000-999)
L Leap Second Indicator (space, L)
D Daylight Saving Time Indicator (S,I,D,O)

The leading edge of the first character (CR) 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.

The Daylight Saving Time indicator (D) is defined as:

S During periods of Standard time for the selected DST schedule.
I During the 24-hour period preceding the change into DST.
D During periods of Daylight Saving Time for the selected DST schedule.
O During the 24-hour period preceding the change out of DST.

Example:

? 15 271 12:45:36.123 S

The example data stream provides the following information:

Sync Status The clock has lost GNSS time sync.
Date Day 271 of year 2015.
Time 12:45:36 UTC time, Standard time is in effect.