PNI CompassPoint V2Xe - Manual (Page 10)

V2Xe User Manual – May 2012 Page 8
5 Operation with V2Xe Protocol
The following section describes the data structure and the commands used to communicate with
the V2Xe over its SPI interface.
5.1 Datagram Structure
The datagram structure for a basic message is given below:
Example: the command for kStartCal would be as specified below.
The datagram for a message with data is given below. This is a variable length message
depending on the number of parameters.
Example: the command for kSetDataComponents with parameters kHeading and
kMagnitude is specified below.
Sync Flag
0xAA
Byte 1
Frame Type
0x03
Byte 2
(kSetData
Components)
Param Count
0x02
Byte 3
Param 1
0x05
Param 2
0x06
Terminator
0x00
Byte 4
(kHeading)
Byte 5
(kMagnitude)
Byte 6
Sync Flag
0xAA
Byte 2
Frame Type
0xXX
Byte 1 Byte 3
Optional Data Field
0xXX, 0xXX,…
Byte 4
Terminator
0x00
Sync Flag
0xAA
Byte 2
(kStartCal)
Frame Type
0x0A
Byte 1 Byte 3
Terminator
0x00
Sync Flag
0xAA
Byte 2
Frame Type
0xXX
Byte 1 Byte 3
Terminator
0x00