User Manual

Iridium Communications, Inc. Information Contained in this Guide
Iridium 9523 Product Developers’ Guide is Subject to Change Without Notice
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–MSVLS: <mode>
Test Command: –MSVLS=?
List the supported parameter settings. The response is in the form:
–MSVLS: (supported <mode>s)
Note: DTMF generated with the –MSVTS command is never played back locally as tones and is therefore
neither played nor muted under control of the –MSVLS command.
5.7.74 –MSSTM - Request System Time
Exec Command: –MSSTM
Query the latest system time received from the network. The response is the form:
–MSSTM: <system_time>
<system_time> can take one of the following forms:
no network service The Iridium 9523 has not yet received system time from the network.
XXXXXXX Where XXXXXXXX is the current Iridium system time available from the
network. The system time as received through the Iridium Air Interface,
is a 32 bit integer count of the number of 90 millisecond intervals that
have elapsed since the epoch. The return value is formatted as an ASCII
hexadecimal number. The counter will rollover approximately every 12
years or be changed to prevent a rollover and as a result should not be
used as a time source for user applications.
Iridium system time epoch: March 8, 2007, 03:50:21.00 GMT. (Note: the original Iridium system
time epoch was June 1, 1996, 00:00:11 GMT, and was reset to the new epoch in January, 2008).
Iridium system time source: The system time is available and valid only after the Iridium 9523 has
registered with the network and has received the Iridium system time from the network. Once the time is
received, the Iridium 9523 uses its internal clock to increment the counter. In addition, at least every 8
hours, or on location update or other event that requires re-registration, the Iridium 9523 will obtain a new
system time from the network.
Time localization: None. The system time value is always expressed in GMT time.
Resolution and accuracy: The resolution of the system time is one Iridium frame tick, or 90 ms. Accuracy
as measured by the difference between the time reported and the actual time this message is sent out of
the Iridium 9523’s serial port should not exceed 4 frame ticks (.36 seconds) and in most cases will be one
frame tick (.09 seconds) or less.
5.7.75 –MSGEO - Request Geolocation
Exec Command: –MSGEO
Query the geolocation grid code received from the network in the last Access Decision Notification
message. The response is of the form:
–MSGEO: <x>,<y>,<z>,<time_stamp>
<x>, <y>, <z> is a geolocation grid code from an earth centered Cartesian coordinate system, using
dimensions, x, y, and z, to specify location. The coordinate system is aligned such that the z-axis is
aligned with the north and south poles, leaving the x-axis and y-axis to lie in the plane containing the
equator. The axes are aligned such that at 0 degrees latitude and 0 degrees longitude, both y and z are
zero and x is positive (x = +6376, representing the nominal earth radius in kilometres). Each dimension of
the geolocation grid code is displayed in decimal form using units of kilometres. Each dimension of the
geolocation grid code has a minimum value of –6376, a maximum value of +6376, and a resolution of 4.