X
X
L
L
D
D
C
C
M
M
A
A
N
N
.
.
d
d
o
o
c
c
3
3
-
-
6
6
R
R
E
E
V
V
E
E
New threshold values entered are retained upon power-down and are the new defaults upon
subsequent power-ups.
3-21 FRONT PANEL INTERFACE
The primary user interface on Model XL-DC-600 is the Serial Port (refer to the section on Serial
functions). On Models XL-DC-601 and XL-DC-602, the front panel is the primary user interface. Input
is via three front panel push-buttons and a 16-key keypad, output is via a two line 32-character
alphanumeric display that provides status and various function information. Model XL-DC-602 includes
a one line ten-character numeric display. The 0.6 inch high numeric LCD continuously displays day-of-
year, time and status annunciators.
3-22 NUMERIC DISPLAY
The primary function of the numeric display is to display the current time. Additionally, the numeric
display has the ability to indicate the occurrence of initial time lock, receiver tracking status and, in the
case of an unlocked condition, the worst case clock time inaccuracy.
Prior to initial satellite lock, an "A" character will be displayed at the far left of the display indicating the
receiver has not achieved a locked condition since power-up and thus is still in the initial acquisition
mode. When initial time lock has occurred, the "A" will be extinguished and will not reappear until
power is cycled.
Prior to initial time lock, an "unlock" annunciator will be visible on the display. This annunciator will
extinguish when the clock has confirmed correct day of year, hour, minute and second, and the 1 PPS
output is within specifications. This annunciator will reappear whenever satellite lock is lost or
measured time error exceeds specifications.
If lock with all satellite signals is lost, "UNLOCK" shows on the numeric display and the Serial Function
F53 command returns "F53 MODE: 0 SATS", where "MODE" is the current operating mode, i.e. AUTO,
SURVEY, TIME. If the time quality indicators are enabled, the display indicates the worst-case time
error in a different manner for each of four thresholds. The user may enable, disable and set these
thresholds using Keypad Function 05 or Serial Function F05. When the worst-case error calculation
reaches the first threshold an asterisk (*) shows on the display. When the worst-case error calculation
increases to the second threshold the asterisk starts flashing. When the calculation increases to the
third threshold both colons (:) and the asterisk flash. When the calculation increases to the last
threshold, the time, colons and asterisk all flash.
3-23 ALPHANUMERIC DISPLAY
The alphanumeric display is used both to display current clock status and as a means of
communicating information accessible through the XL-DC list of keypad functions.
When not being used for keypad function operation, the alphanumeric display can be set to display the
current clock mode and satellite tracking status or the current time with calendar day and year. Current
position information is also available, but, because it requires several screens to display all of the
position information, current position information is only updated upon subsequent requests.
Summary of Contents for 151-600
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