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NI 9214 Operating Instructions and Specifications
14
ni.com
Figure 6.
Input Circuitry for One Channel of the NI 9214
Each thermoco
u
ple channel has a programmable open
thermoco
u
ple detection (OTD) circ
u
it, which consists of a c
u
rrent
so
u
rce between the TC+ and TC– terminals. If an open
thermoco
u
ple is connected to the channel, the c
u
rrent so
u
rce forces
a f
u
ll-scale voltage across the terminals. Yo
u
can config
u
re the
OTD circ
u
it in software. Refer to the software help for information
abo
u
t config
u
ring the OTD circ
u
it. Visit
ni.com/info
and enter
c
s
erie
s
doc
for information abo
u
t C Series doc
u
mentation.
TC+
TC–
COM
NI 9214
Inp
u
t
Imped
a
nce
10 M
Ω
10 M
Ω
Open
Thermoco
u
ple
Detection
C
u
rrent
Filtered
Differenti
a
l
Amplifier
a
nd
M
u
ltiplexer
I
s
ol
a
ted
ADC
NI_9214.fm Page 14 Monday, November 1, 2010 9:52 AM