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SECTION V
IRIG B SYNCHRONIZATION OPTION
5.1
IRIG B SETUP AND OPERATION
5.1.1
This Section describes setup and operating procedures for using the NTS-100 with IRIG
B as the synchronization source.
5.1.2
The NTS-100 IRIG-B Sync Input characteristics are:
Format:
IRIG-B
Input Range:
0.5 Vpp to 5.0 Vpp
Input Z:
10 K
Ω
Accuracy:
± 5 µs, with respect to the input code
5.1.3
After making the appropriate input connection and applying power, the Serial I/O port or
front panel keypad must be used to continue setup of the NTS-100.
5.1.4
Since IRIG B does not contain year information, the date must be set using Function 03.
Function 03 is described in detail in Section 3. To set the date via the Serial I/O port,
send the string:
F03 UTC MM/DD/YY ;<CR>
or, to set the date via the front panel keypad:
5.1.5
Press "FUNC/ENTR" “0” “3” "FUNC/ENTR", use the keypad to enter the date, then press
"FUNC/ENTR", use the keypad to enter the approximate time, then press "FUNC/ENTR".
5.1.6
Using Serial I/O F03 in this manner does not affect the time. Only after the date has
been entered will the NTS-100 indicate a lock to the incoming IRIG B time code, and
respond to NTP packet requests with the Leap Indicator bits set to a value other than 3,
the alarm condition.
5.1.7
Although it is not absolutely necessary to provide leap second information to the
NTS-100 with IRIG-B synchronization option, if it is not provided there are two potential
drawbacks:
•
The NTS-100 will not place any advance indication in the Leap Indicator field of the
NTP packet of an impending leap second event. Refer to Appendix A for details of
the NTP packet format.
•
There will be a short period at and following the occurrence of the leap second event
during which the NTS-100 time will disagree with the IRIG-B synchronization source
(assuming that the IRIG-B source is maintaining strict UTC). This will only persist
until the NTS-100 has determined that a valid time step of the input IRIG-B has
occurred (a few seconds) and corrects its time to match the IRIG-B source. During
this period, NTP packet timestamps created by the NTS-100 will be in error.
Содержание IRIG NTS-100
Страница 1: ...Network Time Server IRIG NTS 100 600 201 SERIAL NUMBER_______________ Revision A January 20 1997...
Страница 42: ...1 20 97 N NT TS S 2 20 01 1 M MA AN N 4 4 1 1 R Re ev v A A 4 SECTION IV NOT USED...
Страница 75: ...1 20 97 N NT TS S 2 20 01 1 M MA AN N C C 1 1 R Re ev v A A APPENDIX D DETAILED DRAWINGS BILL OF MATERIALS...
