X
X
L
L
D
D
C
C
M
M
A
A
N
N
.
.
d
d
o
o
c
c
3
3
-
-
1
1
4
4
R
R
E
E
V
V
E
E
3-107 KEYPAD FUNCTION 07 - EXTERNAL OSCILLATOR ENABLE (OPTION)
Use Function 07 in conjunction with Function 14 to enable or disable Phase Locking to an External
Oscillator. The hardware configuration of the XL-DC must be able to support this function. The as
shipped default is "on". The default value on power-up will be that in use prior to power-down.
Press "FUNC/ENTR" then "0" "7". The display will show:
Ext Oscillator or
Ext Oscillator
DISabled
ENabled
Press the up or down arrow keys to toggle between "Disabled" and "Enabled". When the display
shows the desired choice, press "FUNC/ENTR" to enter your choice.
3-108 through 3-112 reserved
3-113 KEYPAD FUNCTION 13 - WORST-CASE TIME ERROR REQUEST
Use Function 13 to display the worst-case time error due to oscillator drift during periods when satellites
are not being tracked.
Press "FUNC/ENTR", then "1" "3". The display will show:
Time error
Over range
if the unit has not yet acquired valid time, or:
Time error +
00.000 000 200
if the unit is tracking satellites and has acquired valid time.
If the XL-DC acquired valid time, but subsequently lost lock to the satellite signals, the time output will
begin to drift. This drift is dependent on the stability of the internal or the optional external oscillator and
the accuracy to which it had been set on frequency prior to the outage. The stability of the optional
external oscillator must be entered using Keypad or Serial Function 14. The processor calculates and
displays in seconds the worst-case time based on the stability of the oscillator in use.
3-114 KEYPAD FUNCTION 14 - EXTERNAL OSCILLATOR PARAMETER ENTRY/REQUEST
(OPTION)
If the external oscillator is enabled (Function 07), the parameters of the external oscillator are used to
calculate the control coefficients and the worst-case time error as described by Function 13. Use
Keypad Function 14 or Serial Function F14 to set or determine the parameters of the external oscillator.
The default values on power-up will be those in use prior to power-down.
Press "FUNC/ENTR" then "1" "4". The display will show:
External Osc.
FREQ _1 MHz
Summary of Contents for 151-600
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