Novatel OM-20000041 用户手册

D

Logs summary

198

 MiLLennium GPSCard Software Version 4.50 Command Descriptions Manual Rev 1

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

L

1

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.

0

Normal operation is indicated by a 0 value.

1

These bits are set to 1 to inform the user when any of the 8-Kilobyte output buffers have reached an over-

 run condition (

COM1

 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.

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 

R

v

SA

 log message. The flag resets to 0 five

minutes after the first overload occurred.

As the amount of 

CPU

 power becomes limited, the software will begin to slow down the position 

calculation rate. If the 

CPU

 becomes further limited, the software will begin to skip range measurement 

processing. Priority processing goes to the tracking loops.

0

Almanac not saved in non-volatile memory.

1

Almanac saved in non-volatile memory (12 channel OEM cards only).

1

When set to 1, the 

L

2 

AGC

 circuits are operating within normal range of control.

0

This bit will be set clear if the 

L

2 

AGC

 is operating out of normal range. Intermittent setting of the 

AGC

 bit

indicates that the card is experiencing some electro-magnetic interference of a very short duration.
Continuous setting of the 

AGC

 bit may indicate that the card is receiving too much signal power from the

antenna or that a more serious problem with the card may exist. 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.

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

L

2

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. 

1

When the L2 RF downconverter passes self-test, the bit will be set to 1.

0

If a fault is detected in the L2 RF downconverter, this bit is set to 0.