NTS 01 Rev 1 – User Manual March 2006
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Page 12 of 31
Tekron International Ltd
PO Box 31 285 Lower Hutt 6009 New Zealand
tel:
+64 4 566 7722
fax:
+64 4 569 9272
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4.3
Front Panel LEDs:
The
GPS
LED shows the status of the internal GPS receiver, while the
SYN
LED shows the
status of the time synchronisation to UTC reference time derived from the GPS satellites.
By default,
all
outputs (NTP and IRIG-B) become active within a few seconds of initial
power-up even when the unit is
not
synced to GPS satellite time! Output time data is not
precise until the unit is synced to the GPS satellites (or to incoming IRIG-B signal when
operating in “Slave” mode).
Warning Status Indications – (SYN LED not illuminated)
The sync relay is deactivated (“C” connected to NC”). The accuracy of the clock outputs is not
guaranteed to be correct for syncing purposes! The
GPS
LED shows warning states as follows:-.
Warning Status 1:
GPS
LED flashing with a four-flash “burst” pattern, repeating each second: Either the antenna
is not connected, or it is short or open-circuited. When the antenna is operating correctly, this
sequence will not be seen. When the NTS01 is configured to operate in Slave mode
(synchronising to IRIG-B input signal on P4) this flash pattern indicates that the IRIG-B signal
is not present, or is unreadable.
Warning Status 2:
GPS
LED flashing with a two-flash “burst” pattern, repeating each second: The unit is
searching the sky for satellites to begin the sync process. In Slave mode (synchronising to IRIG-
B input signal on P4) this flash pattern indicates that the incoming signal has been recognised,
but that the unit has not yet synchronised to it. In practice, the NTS01 slave sync algorithm is
extremely rapid, so that this status signal will rarely be seen when operating in Slave mode.
OK Status indications – (SYN LED is illuminated continuously)
The
GPS
LED flashes with a single flash each second, with the “ON” period much longer than
the “OFF” period. The sync relay output is activated, giving both visual and electrical
indications that the system is operating normally. All of the output time data is then accurate and
usable for sync purposes.
The Time Server first shows this status after obtaining satellite sync (with 4 or more satellites
being tracked) and maintains this status indefinitely for as long as at least one satellite is being
tracked successfully. (The 2
nd
status character on the LCD display shows the number of
satellites actually being tracked at any given time.) In Slave mode (synchronising to IRIG-B
input signal on P4) this flash pattern indicates that the unit is synched to the IRIG-B signal, and
that all outputs are operating correctly.
