Globalstar SmartOne - Manual (Page 69)

SmartOne Manual Rev 1.4 DOC# 9100-0268-01 p.69
Another example, using a longer message as supported by firmware version 2.1
and higher:
The host sends:
AA 0D 26 10 22 33 44 55 66 77 88 <CRC-low> <CRC-High>
Note the length field: 0D – 0D is the number 13 in hexadecimal, the length of
the total serial command.
The SmartOne would respond:
AA 05 26 <CRC-Low> <CRC-High>
What would go out over the air is:
11 Lat-3 Lat-2 Lat-1 Lon-3 Lon-2 Lon-1 22 33 44 55 66 77 88 00 00 00 00
Note that all on air messages are padded to a multiple of 9 bytes. This is
the reason for the trailing zeros in this example.
Note that the least two significant bits of the first byte are always “01”
for a trunc message, the remaining 6 bits make up the top 6 bits of the first
byte sent in the serial command, in this example 000100xx (with the “xx”
representing the two bits that the SmartOne forces to “01”.
The 22 and the 33 that the user sent are appended after the 6 bytes of
latitude and longitude.
Send Raw Message (serial message type 0x27)
The SMARTONE will send raw user data using the Raw Payload command 0x27.
8 bytes plus 6 bits of user data may be sent. Two bits are set in the on-air
message by the SmartOne informing the recipient that the message is Raw.
The following table defines the message structure used to send a Raw message.
Raw Payload Serial Message
Byte Bit Parameter Description Default
Value
0 7:2 Submask Bits User data bits. Bits 1:0 are reserved and will be
masked by SmartOne. 0x00
Variable User Data Any user data
Firmware version 2.0 supports a maximum of 8 total
bytes of data in this field. Version 2.1 and higher
supports a maximum of 53 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.
Example of sending a “raw” user message:
She Host sends:
AA 0E 27 10 22 33 44 55 66 77 88 99 <CRC-low> <CRC-high>
The SmartOne Responds: