NI 9478 Operating Instructions and Specifications
8
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Connect the device to DO and the positive lead of the power
s
u
pply. Refer to Fig
u
re 2 for an ill
u
stration of how to connect
a device to the NI 9478.
Figure 2.
Connecting a Device to the NI 9478
Yo
u
m
u
st connect the V
s
u
p
pin to the power s
u
pply to enable a
weak cable clamping diode that protects the mod
u
le from cable
ind
u
ctance flyback. This flyback voltage res
u
lts from small
amo
u
nts of energy stored in the ind
u
ctance of the cabling. Refer
section for more information abo
u
t
protection from cable ind
u
ctance flyback. Yo
u
still m
u
st install an
external flyback diode when switching ind
u
ctive loads. Refer to the
Protecting the Module from Flyback Voltages
section for more
information abo
u
t installing a flyback diode.
Device
+
–
NI 947
8
COM
V
su
p
DO
External
Power
S
u
pply
Cable
Clamp
