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H NovAtel Format Logs
Bit State
Bits 12, 13,
Buffer COM 1 / COM 2
14
Normal operation is indicated by a 0 value.
0
These bits are set to 1 to inform you when any of the 8-Kbyte output buffers have reached an over-run condition (COM1
1
or COM2). Over-run is caused by requesting more log data than can be taken off the GPSCard because of bit rate
limitations or slow communications equipment. If this happens, the new data attempting to be loaded into the buffer will
be discarded. The receiver will not load a partial data record into an output buffer. The flag resets to 0 five minutes after
the last overrun occurred.
Bit 15
CPU Overload
0
Normal operation is indicated by a 0 value.
1
A value of 1 indicates that the CPU is being over-taxed. This may be caused by requesting an excessive amount of
information from the GPSCard. If this condition is occurring, limit redundant data logging or change to using binary data
output formats, or both. You should attempt to tune the logging requirements to keep the idle time above 20% for best
operation. If the average idle % drops below 10% for prolonged periods of time (2-5 seconds), critical errors may result
in internal data loss and the over-load bit will be set to 1. You can monitor the CPU % idle time by using the RVSA log
message. The flag resets to 0 five minutes after the first overload occurred.
Bit 16
Almanac Saved
0
Almanac not saved in non-volatile memory.
1
Almanac saved in non-volatile memory.
Bit 17
Secondary AGC
0
This bit will be set clear if the Secondary AGC is operating out of normal range. Failure of this test could be the result of
various possibilities, such as: bad antenna LNA, excessive loss in the antenna cable, faulty RF downconverter, or a
pulsating or high power jamming signal causing interference. If this bit is continuously set clear, and you cannot identify
an external cause for the failed test, please contact NovAtel Customer Service.
1
When set to 1, the Secondary ARG circuits are operating within a normal range of control.
Bit 18
Secondary Jammer Detection
0
Normal operation is indicated when this bit is 0.
1
If set to 1, the receiver has detected a high power signal causing interference. When this happens, the receiver goes into
a special anti-jamming mode where it re-maps the A/D decode values as well as special Secondary AGC feedback
control. These adjustments help to minimize the loss that will occur in the presence of a jamming signal. You should
monitor this bit, and if set to 1, do your best to remedy the cause of the jamming signal. Nearby transmitters or other
electronic equipment could be the cause of interference; you may find it necessary to relocate your antenna position if the
problem persists.
Bit 19
Secondary PLL
0
If a fault is detected in the Secondary RF downconverter, this bit is set to 0.
1
When the Secondary RF downconverter passes self-test, the bit will be set to 1.
Bit 20
OCXOPLL
0
If a fault is detected in the OCXOPLL bit, this bit is set to 0.
1
When the OCXOPLL bit passes self-test, the bit will be set to 1.
Bit 21
Saved Almanac Needs Update
0
This bit will be set to 0 if an almanac has not been received that is newer than the one stored in memory.
1
When the almanac received is newer than the one currently stored in NVM (non-volatile memory), the bit will be set to 1.
Bit 22
Almanac Invalid
0
Valid almanac in use.
1
No almanac in use
98
* see note 1 below
Description
GPS/GLONASS Receiver User Manual Rev 1
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