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Data Logs
34
 MiLLennium GPSCard Software Version 4.50 Command Descriptions Manual Rev 1
3
DATA LOGS
3.1 OUTPUT LOGGING
The GPSCard provides versatility in your logging requirements.  You can direct your logs to either 
COM1
 or 
COM2
,
or both ports, as well as combine data types.  The GPSCard has four major logging formats:
NovAtel Format Data Logs (ASCII/Binary)
NMEA
 Standard Format Data Logs (ASCII)
RTCM
 Standard Format Data Logs (Binary)
RTCA
 Standard Format Data Logs (Binary)
All data types can be logged using several methods of triggering each log event.  Each log is initiated using the 
LOG
command.  The 
LOG
 command and syntax are listed below.
Syntax:
log [port],datatype,[trigger],[period],[offset],{hold}
Example:
log com1,posa,ontime,60,1
If the 
LOG
 syntax does not include a trigger type, it will be output only once following execution of the 
LOG
Syntax
Description
Example
LOG
LOG
port
COM1 or COM2 
COM1
datatype
Enter one of the valid ASCII or Binary Data Logs (see later in this chapter and Appendix D, Page 136)
POSA
trigger
Enter one of the following triggers.
ONTIME
ONCE
Immediately logs the selected data to the selected port once.  Default if trigger field is left blank.
ONMARK
Logs the selected data when a MARKIN electrical event is detected.  Outputs internal buffers 
at time of mark - does not extrapolate to mark time. Use MKBA/B for extrapolated position at 
time of mark.
ONNEW
Logs the selected data each time the data is new even if the data is unchanged.
ONCHANGED
Logs the selected data only when the data has changed.
ONTIME
[period][offset]
Immediately logs the selected data and then periodically logs the selected data at a frequency 
determined by the period and offset parameters.  The logging will continue until an UNLOG 
command pertaining to the selected data item is received (see UNLOG Command, Page 132).
CONTINUOUSLY
Will log the data all the time.  The GPSCard will generate a new log when the output buffer 
associated with the chosen port becomes empty. The continuously option was designed for 
use with differential corrections over low bit rate data links.  This will provide optimal record 
generation rates.  The next record will not be generated until the last byte of the previous record 
is loaded into the output buffer of the UART.
period
Use only with the
ONTIME 
trigger.  Units for this parameter are seconds. The selected period may be any of the 
following values: 0.05, 0.10, 0.20, 0.25, 0.50, 1, 2, 3, ... , 3600 seconds but may be limited by the GPSCard model 
and previously requested logs. Selected data is logged immediately and then periodic logging of the data will start at 
the next even multiple of the period.  If a period of 0.20 sec is chosen, then data will be logged when the receiver time 
is at the 0.20, 0.40, 0.60 and the next (0.80) second marks.  If the period is 15 seconds, then the logger will log the 
data when the receiver time is at even 1/4 minute marks.  The same rule applies even if the chosen period is not 
divisible into its next second or minute marks.  If a period of 7 seconds is chosen, then the logger will log at the 
multiples of 7 seconds less than 60, that is, 7, 14, 21, 28, 35, 42, 49, 56 and every 7 seconds thereafter.
60
offset
Use only with the 
ONTIME 
trigger.  Units for this parameter are seconds.  It provides the ability to offset the logging 
events from the above startup rule.  If you wished to log data at 1 second after every minute you would set the period 
to 60 seconds and the offset to 1 second (Default is 0).
1
hold
Will prevent a log from being removed when the 
UNLOGALL
 command is issued
HOLD
3
 
DATA LOGS