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SmartOne C User Manual
Confidential & Proprietary Information
9100-0410-01 R2.4
SERIAL COMMANDS
The SmartOne uses the multi-functional user interface 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. The rate is specified by the Undesired Input State message interval.
This section describes the serial interface between the SmartOne and a computer or other programming device.
SmartOne will respond to any invalid command with a NAK response (payload field set to 0xFF).
SERIAL PACKET FORMAT (COMMANDS AND RESPONSES)
Communication to the SmartOne will follow the following specific format:
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
1 BYTE
1 BYTE
1 BYTE
Variable length 0 – 54 bytes
2 bytes
PREAMBLE
FIXED PATTERN 0XAA
LENGTH
Total number of bytes in the serial packet including the preamble
CMD
Command type (See table below). Responses to commands carry the same
command type as the command that initiated the answer
DATA
Data associated with the command or answer
CRC LOW
Least significant byte of the 16-bit CRC
CRC HIGH
Most significant byte of the 16-bit CRC
