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5.1.8
During the six months prior to the addition of a new leap second, the USNO will publish
to the user community its plan to implement a leap second. Leap seconds are added (or
subtracted) only at the end of the days of June 30 and December 31. If the NTS-100 is
informed of an impending leap second adjustment at any time during the six months prior
to the next leap second adjustment, then it will store that information in its EEPROM.
When the time for the leap second adjustment approaches, the NTS-100 will
automatically place the appropriate information in the Leap Indicator field of the NTP
packet and at the appropriate time will perform the leap second correction to its internal
clock. Use Serial I/O Function F67, which is described in detail in Section 3, to provide
this information to the NTS-100.
5.1.9
When operating the NTS-100 from an IRIG-B synchronization source, the operator must
input information about the clock which is producing the IRIG-B signal. The parameter
which is required is entered using the Serial I/O Function F36 and is the “Clock
Accuracy” field. This field must specify the accuracy of the clock which is being used to
generate the IRIG-B code. Refer to Section 3, Function F36 and Appendix A for more
detail on the setting of this parameter.
5.1.10
In addition, if the incoming IRIG-B sync input contains embedded Lock Quality indicators
then the operation of the NTS-100 with respect to these must be configured via Function
36:
F36 Keypad Operation:
5.1.11
Pressing "FUNC/ENTR" on “Display/Setup IRIG Lock Quality” enables the user to view
and/or change the bit in the IRIG code which determines the status of the NTS-100 lock
indicators. The format of the IRIG Lock Quality display is shown here:
IRIG-B Lock
Quality: Lock
(Example)
5.1.12
Pressing the Up and Down arrows scrolls through the selections for Lock Quality: Lock,
TQ1, TQ2, TQ3, TQ4, and None. When the desired selection is displayed, press
"FUNC/ENTR" to enter the selection and proceed to the next parameter, “CLR” to restore
the original setting, or “STATUS” to exit function 36 without saving any updated settings.
F36 Serial I/O Operation:
5.1.13
The IRIG Lock Quality determines the bit in the incoming IRIG data which the NTS-100
uses to determine whether or not it is receiving valid time. Possible settings are: Lock,
TQ1, TQ2, TQ3, TQ4, and None. To determine the current configuration of the
NTS-100, send the string:
F36 IQ<CR><LF>
5.1.14
The unit will respond with:
F36 IQ: setting
