Type 1 message class – Globalstar SmartOne User Manual

Page 58

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SmartOne Manual Rev 1.4 DOC# 9100-0268-01 p.58

the fix.) Value 0 = GPS data
reported is from a 3D fix.

8

Motion

1

Bit (6) – Value 1 = Device was
In-Motion when the message was
transmitted. Value 0 = Device
was At-Rest when the message
was transmitted.

8

Fix Confidence
Bit.

1

Bit (7) 0=High confidence in
GPS fix accuracy, 1=Reduced
confidence in GPS fix accuracy.

Table 7 - Re-center Message

Type 1 Message Class


Truncated message type – Single Packet Version (Supported in
firmware version 2.0 and later.)

This message type provides for up to 2 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 serial configuration port. 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

Byte 1 = 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 correspond to East Longitudes
Positive Latitude correspond to North Latitudes

User Data

16

Byte 1 = User data byte 1
Byte 2 = User data byte 2

Truncated message type – Multiple Packet Version (Supported in
firmware version 2.1 and later.)

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

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