National Instruments SCXI-1520, Процедура калибровки

Страница: 13 / 24

© National Instruments Corporation 13 SCXI-1520 Calibration Procedure
Adjusting Calibration Constants
Complete the following steps to adjust the calibration constants on the
SCXI-1520.
Gain Calibration Constants
1. Calculate the gain adjustment for each channel using the following
equation:
where
GainAdjust is a value used later in this process
V
mp
is the measured output of the module given a positive input
voltage V
inp
V
mn
is the measured output of the module given a negative input
voltage V
inn
gain is the gain setting of the module
2. Call
SCXI_Adv_Module_Write
to write the new gain calibration
constants to the module. Set the following parameters:
• SCXIchassisID —The value assigned by MAX
• moduleSlot —1
• moduleClass —2
• address —2
×
iquo + 9, where iquo is the integer part of the
module channel divided by 2
• numBytes —4
• data —The value of GainAdjust represented as 4 bytes in
a 4-element array stored little-endian
• whichAccess —0
• regMethod — –1
• subAddress —(296
×
irem + 722) + (4
×
index ), where irem is the
integer remainder of the module channel divided by 2 and index
is the index from Table 2 that corresponds to the gain you are
adjusting
3. Repeat steps 1 and 2 for the remaining gains and channels.
GainAdjust
V
mp
V
mn
–
V
inp
V
inn
–
( )
gain
×
------------------------------------------------ =