Chapter 3
Configuring Your SCXI Hardware and Software
©
National Instruments Corporation
3-21
5.
Enable the half-bridge completion network, if necessary.
The SCXI-1121 includes a built-in half-bridge completion network
to use with half-bridge or quarter-bridge transducers. The network
includes two 4.5 k
Ω
(±0.05%) resistors, connected in series, with a
temperature coefficient of 5 ppm/°C. You can enable the network on
an individual channel basis using two additional jumpers per
channel—W1, W2, W17, W18, W27, W28, W39, and W40. When you
enable the completion network, you automatically remove access to
the negative input of the amplifier to preserve overvoltage protection.
See Table 3-15 for half-bridge completion network jumper
information, and refer to Figures 4-5, 4-6, and 4-7 for diagrams of
standard bridge configurations.
Table 3-14.
SCXI-1121 Maximum Load per Excitation Channel
Excitation Level
Maximum Load
3.333 V
28 mA
10 V
14 mA
0.150 mA
10 k
Ω
0.450 mA
10 k
Ω
