Serial Commands; Serial Packet Format (Commands And Answers); Serial Packet Fields - Globalstar SmartOne Solar User Manual

9100-0425-01

4. Serial Commands

The SmartOne uses the I/O port for unit configuration as well as interface to remote passive and smart
sensors. Two commands are provided in the unit interface to support smart sensors. External sensors
that can format and communicate to the SmartOne can send user data through the SmartOne by using
these two commands.
This section describes the serial interface between the SmartOne and a computer or other programming
device. SmartOne will respond to any command that contains fields with invalid values with a NAK
response (command field set to 0xFF).
Describe Bluetooth Interface in this Section

Serial Packet Format (commands and answers)

Communication to the SmartOne will follow the following specific format:
Preamble Length
1 byte 1 byte
Total length range permitted: 5 bytes (Data field length 0) to 59 bytes (Data field length 54).

Serial Packet Fields

The different fields are defined as:
Preamble
Length
Cmd
Data
CRC Low
CRC High
SmartOne Solar™ User Guide v1.0.3
Cmd
Variable length 0 – 54 bytes
1 byte
Fixed Pattern 0xAA
Total number of bytes in the serial packet including the preamble
Command type (See table below). Responses to commands carry the
same command type as the command that initiated the answer
Data associated with the command or answer
Least significant byte of the 16-bit CRC
Most significant byte of the 16-bit CRC
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Data CRC
2 bytes
20