Novatel OM-20000041 用户手册

Command Descriptions

MiLLennium GPSCard Software Version 4.50 Command Descriptions Manual Rev 1

The GPSCard is capable of logging almanac data utilizing the NovAtel-format ASCII log command option

ALMA

Once logged, the data records will precede the header with the $ character (e.g., $

ALMA

There are no specific NovAtel log option commands to independently specify output of ionospheric or

UTC

parameters. These parameters will always output following the $

ALMA

log (identifiable by the headers $

IONA

and

UTCA

respectively). See Chapter 3 and Appendix D, Page 136 for more information on the

ALMA

output log

command option.

The GPSCard has the capability to accept injection of previously logged NovAtel-format ASCII almanac data
($

ALMA

, $

IONA

, and $

UTCA

). The GPSCard will interpret this log data as special data input commands. This

provides the user with the advantage of being able to inject recent almanac data following a cold-start or

RESET

without having to wait the 12.5 minutes described in above paragraphs.

There are various ways by which this can be accomplished.

•

By connecting the

COM1

COM2

port from one GPSCard (reference) directly to the

COM1

COM

2 port of another GPSCard (remote). The reference card is assumed to be tracking

satellites for some time and can be commanded by the

ALMA

log command option to output

almanac records to the remote card. The remote card can be assumed to be just powered-up
or

RESET

and will recognize the $

ALMA

, $

IONA

, and $

UTCA

data as special input commands

and update its almanac tables with this new data.

REMEMBER:

When connecting two GPSCard

COM

ports together, the

MESSAGES

command option should be

set to "

OFF

" to prevent inter-card "chatter".

•

The MiLLennium GPSCard can log current almanac data to a PC connected to its

COM1

COM2

port. Assuming the PC is correctly configured using terminal emulator

communications software, then the PC can redirect the GPSCard almanac log to its disk
storage device. At a later time following a system restart, the GPSCard can have this
almanac.dat file (containing $

ALMA

, $

IONA

, and $

UTCA

records) immediately downloaded

as a special input command for immediate use. Refer to the MiLLEnnium GPSCard Guide
to Installation and Operating manual for more information about interfacing with the

OEM

card with a PC. [Note: this procedure will generally not be required with OEM cards as all
12 channel cards now have an almanac save feature built in using non-volatile memory.]

$ALMA...

Use this special data input command to quickly update the GPSCard almanac tables following a system restart. It
is generated from a GPSCard

ALMA

log and is accepted as the following format:

$ALMA,1,3.55148E-003,552960,744,-7.8174E-009,6.10457691E-002,-1.1820041E+000,
1.90436112E+000,-1.8119E-005,-3.6379E-012,1.45854758E-004,2.65602532E+007,
9.55600E-001,1,0,0*0C
...
(one record for each valid satellite)
...
$ALMA,31,4.90379E-003,552960,744,-7.9660E-009,-3.1044479E+000,6.13853346E-001,
1.92552900E+000,6.67572E-006,3.63797E-012,1.45861764E-004,2.65594027E+007,
9.61670E-001,1,0,0*3F

$IONA...

Use this special data input command to quickly update the GPSCard ionospheric corrections tables following a
system restart (always appended to $

ALMA

records unless intentionally stripped). This data will ensure that the

initial position solutions computed by the GPSCard are as accurate as possible. It is generated from a GPSCard

ALMA

log and is accepted by any GPSCard as the following format:

$IONA,1.0244548320770265E-008,1.4901161193847656E-008,-5.960464477539061E-008,
-1.192092895507812E-007,8.8064000000000017E+004,3.2768000000000010E+004, -
1.966080000000001E+005,-1.966080000000001E+005*02