Ascension laserBIRD, Инструкция по установке и эксплуатации

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4: Software Operation: Tools for Successful Tracking
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BIRD COMPUTER CRYSTAL SPEED
When PARAMETERnumber = 2 during EXAMINE, The Bird returns the speed of its computer's
crystal in megahertz (MHz). The most significant byte of the speed word is equal to zero, and the
base 10 value of the least significant byte represents the speed of the crystal. For example, if the
least significant byte = 19 Hex, the crystal speed is 25 MHz. The laserBIRD always reports 37MHz.
POSITION SCALING
When PARAMETERnumber = 3 during EXAMINE, The Bird returns a code that describes the scale
factor used to compute the position of the sensor with respect to the transmitter. If the separation
exceeds this scale factor, The Bird's position outputs will not change to reflect this increased
distance, rendering the measurements useless. The most significant byte of the parameter word
returned is always zero. If the least significant byte = 0, the scale factor is 36 inches for a full scale
position output. If the least significant byte is = 1, the full scale output is 72 inches
To CHANGE the scale factor send The Bird two bytes of PARAMETERdata with the most
significant byte set to zero and the least significant set to zero or one.
Note: Changing the scale factor from the default 36 inches to 72 inches reduces by half the
resolution of the output X, Y, Z coordinates.
FILTER ON/OFF STATUS
When PARAMETERnumber = 4 during EXAMINE, The Bird returns a code that tells you what
software filters are turned on or off in the unit. The average user of The Bird should not have to
change the filters, but it is possible to do so. The most significant byte returned is always zero.
The bits in the least significant byte are coded per the following:
BIT NUMBER MEANING
B7-B3 0
B2 0 if the AVERAGE
(AC NARROW notch)
filter is ON (default)
1 if the AVERAGE filter is OFF
B0 0 if the DC (Adaptive) filter is ON (default)
1 if the DC filter is OFF
The AVERAGE filter refers to a four element averaging filter that is applied to The Bird's sensor
data to eliminate a narrow band of noise with sinusoidal characteristics.
The DC filter refers to an adaptive, low pass filter applied to the sensor data to eliminate high
frequency noise. When the DC filter is turned on, you can modify its noise/lag characteristics by
changing ALPHA_MIN and Vm.
To CHANGE the FILTER ON/OFF STATUS send The Bird two bytes of PARAMETERdata with the
most significant byte set to zero and the least significant set to the code in the table above.