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. |