Serial Packet Types; Send Truncated Message - Globalstar SmartOne Series User Manual

Serial Packet Types

Cmd Description / Usage / Comment
User requests the SMARTONE to
reply with integral ESN (Electronic
0x01
Serial Number). This is the ID used
by Globalstar to identify the unit.
0x26

Send Truncated message.

0x27 Send Raw Message
Send Truncated Message (serial message type 0x26)
The SMARTONE will perform a GPS location and append user data passed to the
unit via the Truncated Message command 0x26.
Two bytes plus 6 bits of user data may be sent with the standard GPS location
information in a messaging burst. Two bits are set in the on-air message by
the SmartOne informing the recipient that the message is the Truncated type.
The following table defines the message structure of the "data" portion of
the command used to send a Truncated message.
Byte Bit Parameter
0 7:2 Submask Bits
Variable. User Data
Example of sending a "Truncated" user message
The host sends:
AA 08 26 10 22 33 <CRC-low>
The SmartOne would respond:
AA 05 26 <CRC-Low>
What would go out over the air is:
11 Lat-3 Lat-2 Lat-1 Lon-3 Lon-2 Lon-1 22 33
SmartOne Manual Rev 1.5
Truncated Serial Message
Description
User data bits. Bits 1:0 are reserved and will be
masked by SmartOne.
Any user data
Firmware version 2.0 supports a maximum of 2 total
bytes of data in this field. Version 2.1 and higher
supports a maximum of 47 total bytes in this field.
User application (smart sensor) should transmit only
as many bytes as needed (don't "pad" the message) in
order to keep on air packets to a minimum.
<CRC-High>
<CRC-High>
DOC# 9100-0268-01
Command Data Acknowledge Data Bytes
Bytes
Four data bytes, which contain the
unit ID as an unsigned integer.
None
The MSByte is sent first. Only the
27 LSbits are non-zero.
See Truncated
Message section None
below
See Raw Message
None
Section below
Default
Value
0x00
p.68