Page 51
SmartOne C User Manual
Confidential & Proprietary Information
9100-0410-01 R2.4
TRUNCATED MESSAGE TYPE – MULTIPLE PACKET VERSION
The Globalstar Commercial IoT 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. The Truncated message will follow the
following on-air format:
VARIABLE
BITS
DESCRIPTION
STATUS BYTE
8
Bit (1:0) = 1 = Truncated message type
Bit (7:2) = submask data from Truncated user data
LATITUDE/LONGITUDE
48
Byte1 = Latitude MSByte
Byte 2 = Latitude
Byte 3 = Latitude LSByte
Byte 4 = Longitude MSByte
Byte 5 = Longitude
Byte 6 = Longitude LSByte
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
USER DATA
VARIABLE
Byte 1 = User data byte 1
Byte 2 = User data byte 2
Byte 3 = User data byte 3
……
……
……
Byte 47 = User data byte 47
