Truncated Message Type - Multiple Packet Version - Globalstar SmartOne Solar User Manual

9100-0425-01
Variable
Status Byte
Latitude/Longitude
User Data
Truncated Message Type – Multiple Packet Version
The Globalstar simplex messaging protocol provides for single and multiple packet messaging. In the
event that the user application requests a user data length exceeding 9 bytes, the SmartOne (running
firmware version 2.1 or later) will automatically "packetize" the message, that is, transmit it as multiple 9
byte packets. The ground station appliqué will reverse the process, "de-packetizing" the message back
into a single ("long") message. From the user application point of view, this eliminates the 9 byte
limitation allowing the user to compose longer messages transparently. They are presented to the user by
the Globalstar back office as complete messages of a length longer than 9 bytes. The SmartOne supports
user-defined messages (Class 1 and 2) of up to 54 bytes.
This message type provides for up to 47 bytes plus 6 bits of user data to be appended to the status byte
and GPS location information. The input and status bits data of the standard message are replaced with
user data from the configuration port.
NOTE: Total message length will be a minimum of 9 bytes in length, and a maximum of 54 bytes in
length, and the length sent to the user will always be divisible by 9.
SmartOne Solar™ User Guide v1.0.3
Bits Description
Bit (1:0) = 1 Truncated message type
8
Bit (7:2) = Submask data from Truncated user data
Byte 1 = Latitude MSByte
Byte 2 = Latitude
Byte 3 = Latitude LSByte
Byte 4 = Longitude MSByte
Byte 5 = Longitude
Byte 6 = Longitude LSByte
48
360 degrees of longitude coded in signed binary with 3 bytes and
180 degrees of latitude coded in signed binary with 3 bytes
Positive longitude corresponds to East longitudes
Positive Latitude corresponds to North latitudes
See Appendix G for an Lat/Long decoding example
Byte 1 = User data byte 1
16
Byte 2 = User data byte 2
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