Section 3: Operation
Page 3-20
NetClock/GTP Instruction Manual
3.3.5 Format
4
Format 4 provides a format indicator, time sync 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:
FFFFIMJDXX^HHMMSS.SSSS^L CR LF
where:
FFFF = Format Identifier (0004)
I =
Time Sync Status (Space, ? *)
MJDXX = Modified Julian Date
HH = Hours (00-23 UTC time)
MM = Minutes (00-59)
SS.SSSS = Seconds (00.0000-60.0000)
L =
Leap Second Indicator (^, 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 sync status character I is defined as:
(Space) = Whenever the front panel Time Sync lamp is green.
? = When the receiver is unable to track any satellites and the Time
Sync lamp is red.
* = When the receiver time is derived from the battery backed clock
or set manually through the Serial Setup Interface.
The leap second indicator L is defined as:
(Space) = When a leap second correction is not scheduled at the end of the
month.
L = when a leap second correction is scheduled at the months end.
Example
: 0004 50085 124536.1942 L
The example data stream provides the following information:
Data format: 4
Sync Status: Time synchronized to GPS.
Modified Julian Date: 50085
Time: 12:45:36.1942 UTC
Leap Second: A leap second is scheduled at the end of the month.
