National Instruments SCXI-1121 - Manual (Page 24)

Chapter 2 Configuration and Installation
SCXI-1121 User Manual 2-8 www.natinst.com
Input Channel Jumpers
Gain Jumpers
Each input channel has two gain stages. The first gain stage provides gains
of 1, 10, 50, and 100 and the second stage provides gains of 1, 2, 5, 10, and
20. Tables 2-3 and 2-4 show how to set up the gain for each channel.
The board is shipped to you with the first-stage gain set to 100 (position A)
and a second-stage gain set to 10 (position D). To change the gain of your
module, move the appropriate jumper on your module to the position
indicated in Table 2-4. Refer to Figure 2-2 for the jumper locations on your
module.
To determine the overall gain of a given channel use the following formula:
Overall gain = First-stage gain
×
second-stage gain
Table 2-3. Gain Jumper Allocation
Input Channel
Number
First Gain
Jumper
Second Gain
Jumper
0 W3 W4
1 W19 W20
2 W29 W30
3 W41 W42
Table 2-4. Gain Jumper Positions
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