Moog Crossbow GNAV540 - Manual (Page 69)

GNAV540 User Manual
7430‐0808‐01 Rev. B Page 69
This command performs a core CPU reset, functionally equivalent to a power cycle. All default power‐up field
settings will apply. The unit will respond with software reset response before the system goes down.
Software Reset Response
Table 23 Software Reset Response
Software Reset (‘SR’ = 0x5352)
Preamble Packet Type Length Termination
0x5555 0x5352 0x00 <CRC (U2)>
The unit will send this packet in response to a software reset command.
Calibrate Command
Table 24 Calibrate Command
Calibrate (‘WC’ = 0x5743)
Preamble Packet Type Length Payload Termination
0x5555 0x5743 0x02 <WC payload> <CRC (U2)>
This command allows the user to perform various calibration tasks with the GNAV540 unit. See the calibration
command table below for details. The unit will respond immediately with a calibrate response containing the
calibrationRequest
received or an error response if the command cannot be performed.
Table 25 WC Payload
WC Payload Contents
Byte
ffset O
Name Format Scaling Units Description
0 calibrationRequest U2 — — The requested calibration task
Currently, magnetic alignment is the only function supported by the calibrate command. There are two magnetic
alignment procedures supported; (1) magnetic alignment with automatic yaw tracking termination, and magnetic
alignment without automatic termination.
Table 26 Magnetic Alignment
calibrationRequest Description
0x0009 Begin magnetic alignment without automatic termination.
Rotate vehicle through >360 degrees yaw and then send 0x000B
calibration request for termination.
0x000B Terminate magnetic alignment. The unit will send a CC respons
containing the hard‐iron and soft‐iron values. e
To accept the parameters, store them using the write magnetic
calibration command.
0x000C Begin magnetic calibration with automatic termination. Rotate the unit
through 380 degrees in yaw.
oft‐iron The unit will send a CC response containing the hard‐iron and s
values upon completion of the turn.
To accept the parameters, store them using the write magnetic