calmag unit antenna
calmag calibrates the fluxgate compass mounted on the antenna. This command causes the antenna to start its upper wrap and move slowly through 360 degrees, calculating the magnetic flux in the X and Y axes as it turns. A table is displayed as the antenna turns showing the magnetic flux and relative antenna position. Four coefficients are determined that compensate for magnetic fields near the antenna (masts, decking, etc.). The coefficients are stored in the antenna's PCU.
An error is issued if the local magnetic fields vary abnormally. If this error occurs, the antenna must be moved or the magnetic fields removed. The calmag command must be rerun after the magnetic field is removed.
unit - is the telemetry chain whose antenna is to be calibrated. Telemetry chains are numbered 1,2,3...
antenna - specifies that the fluxgate compass on the antenna is to be calibrated to compensate for magnetic fields near the antenna.
[1]%calmag 1 antenna { calibrate antenna associated with chain 1 }
[1]%calmag { calibrate antenna associated with chain 1 }
The calmag command can be used with other antenna diagnostics and commands. If an antenna program is running, the calmag command will be blocked until the antenna program is complete. The commands output to the controller by calmag will not be displayed by the function trackeye. If a GPS unit is part of the antenna, a delay of up to 60 seconds may occur before the commands will be sent to the antenna.
The antenna option for calmag corrects the onboard fluxgate compass only for
metal masses in close proximity to the antenna. It does not correct for the metal mass of
a ship as the ship turns and creates a varying magnetic field.
Last Update: $Date: 2001/12/19 19:32:54 $