NI USB-9213 User Guide and Specifications
12
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Connecting Wires to the NI USB-9213 Connector
Use a flathead screwdriver with a blade smaller than
2.3
×
1.0 mm (0.09
×
0.04 in.) to connect wires to the detachable
spring-terminal connector. Insert the screwdriver into a spring clamp
activation slot and press a wire into the corresponding connector terminal,
then remove the screwdriver to clamp the wire into the terminal. Refer to
the
section for more information about spring-terminal
wiring. Refer to Figure 9 for an illustration of connecting wires to the
NI USB-9213.
Figure 9.
Connecting Wires to the NI USB-9213 Terminals
Wiring for High-Vibration Applications
If an application is subject to high vibration, National Instruments
recommends that you use the NI 9940 backshell kit to protect the
connections. Refer to Figure 3 for an illustration of the NI 9940 connector
backshell.
NI USB-9213 Circuitry
E
ach channel of the NI USB-9213 passes through a differential filter and
then is multiplexed and sampled by a 24-bit analog-to-digital converter
(ADC). Each channel also has an open thermocouple detection (OTD)
circuit, which consists of a current source between the TC+ and TC–
terminals. If an open thermocouple is connected to the channel, the current
source forces a full-scale voltage across the terminals. Refer to Figure 10
for an illustration of the input circuitry for one channel of the
NI USB-9213.
