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EuroPak-15a Receiver User Manual Rev 5
Chapter 5
Commands
5.3.4
CLOCKADJUST
All oscillators have some inherent drift. By default the receiver attempts to steer the receiver’s clock to
accurately match GPS time. If for some reason this is not desired, this behavior can be disabled using the
CLOCKADJUST command. The TIME log can then be used to monitor clock drift, see
.
1.
The CLOCKADJUST command should only be used by advanced users.
2.
If the CLOCKADJUST command is ENABLED, and the receiver is configured to use an external
reference frequency (set in the EXTERNALCLOCK command, see
Page 54
, for an external clock
- TCXO, OCXO, RUBIDIUM, CESIUM, or USER), then the clock steering process will take over
the VARF output pins.
3.
When disabled, the range measurement bias errors will continue to accumulate with clock drift.
4.
Pseudorange, carrier phase and Doppler measurements may jump if the CLOCKADJUST mode is
altered while the receiver is tracking.
5.
When disabled, the time reported on all logs may be offset from GPS time. The 1PPS output may
also be offset. The amount of this offset may be determined from the TIME log, see
Page 97
Abbreviated ASCII Syntax:
Message ID: 15
ASCII Example:
CLOCKADJUST DISABLE
CLOCKADJUST
SWITCH
Field
Field
Type
ASCII
Value
Binary
Value
Description
Binary
Format
Binary
Bytes
Binary
Offset
1
header
This field contains the
Abbreviated ASCII
command name.
See
.
H
0
2
switch
DISABLE
0
Disallow adjustment of
internal clock.
Enum
4
H
ENABLE
1
Allow adjustment of
internal clock.
