Chapter 3
Configuring Your SCXI Hardware and Software
3-16
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b.
Configure the second-stage gain.
Use jumpers W4, W20, W30, and W42 to configure the
second-stage gain of channels 0 through 3, respectively. Each of
these jumpers has five possible positions—A, B, C, D, and
E—each corresponding to a particular gain.
The jumper settings and corresponding gain values are listed in Tables 3-9
and 3-10.
2.
Configure the filtering.
The filtering is also two-stage and is jumper-selectable for each
channel. The SCXI-1121 uses a two-stage filtering configuration to
achieve a higher signal-to-noise ratio. Filter bandwidth does not affect
the maximum scanning rate. The factory-default jumper positions
configures each channel for 4 Hz bandwidth.
Table 3-9.
SCXI-1121 First-Stage and Second-Stage Gain Jumper Configuration
Input Channel
Number
First-Stage Gain
Jumper
Second-Stage Gain
Jumper
0
W3
W4
1
W19
W20
2
W29
W30
3
W41
W42
Table 3-10.
SCXI-1121 Gain Jumper Configuration
Gain
Setting
Jumper Position
First-stage
1
10
50
100
D
C
B
A (factory setting)
Second-stage
1
2
5
10
20
A
B
C
D (factory setting)
E