T801-4 Installation and Operation Manual
Description
15
© Tait Electronics Limited September 2007
GPS LED
This LED has two states:
■
Green indicates that the received 1PPS signal is valid (GPS fix).
■
Red indicates the received 1PPS signal has failed or is invalid.
MASTER
OSCILLATOR LED
This LED has three states:
■
Green indicates that the control process is dynamic and that the master
oscillator frequency has reached a state where the accuracy is better than
±1 part in 10
8
(0.01ppm).
Important
It is important to understand that green means that the
oscillator is approaching its specified maximum accuracy,
and has passed the ±1 part in 10
8
level. Green does not
necessarily mean that the oscillator has reached its specified
maximum accuracy.
■
Amber indicates that the control process is locked because the 1PPS
signal has failed, and the level of accuracy immediately before the 1PPS
failure was better than ±1 part in 10
8
.
■
Red indicates that it is not safe to assume that the master oscillator
frequency is correct. The LED will be red in the following situations:
■
after the LED has been amber (the control process has been
locked) continuously for 24 hours
■
the 1PPS signal is valid but the level of accuracy is less than ±1
part in 10
8
■
the 1PPS signal is invalid and the level of accuracy has not yet
reached a level of ±1 part in 10
8
(usually after initial power-up).
c
d
