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NI 9144 User Guide and Specifications
Use the following equation to calculate the resistance of the thermistor:
where
R
represents the resistance of the thermistor
V
CJCvoltage
= raw CJC voltage
Use the following equation to calculate the CJC temperature:
where
T
represents the temperature in degrees Celsius
R
represents the resistance of the thermistor
A
is 1.2873851 × 10
-3
B
is 2.3575235× 10
-4
C
is 9.4978060 × 10
-8
Offset
represents the offset constant. The value is 1. The constant is the typical
temperature gradient between the CJC sensor and the TC cold junction.
NI 9214
The vendor configuration extensions for the NI 9214 are listed in Table 34.
Table 34.
NI 9214 Vendor Configuration Extensions
Index
Sub
Type
R/W
Description
0x2001
0
ARR:U32
—
Scan List = 21
1
R
Channels to Convert = 1..20,
default = 20
2..21
R/W
Channel Code
0x2002
0
U32
R/W
Conversion Speed Control/Open
Thermocouple Detection
0x2003
0
U32
R
Common Mode Range Error Detection
Status (also as 8-bit PDO)
R
10000 32
V
CJCvoltage
×
×
(
)
2.5 32
V
CJCvoltage
×
–
(
)
÷
=
T
1
A B In R
( )
(
)
C In R
( )
(
)
3
+
+
[
]
÷
[
]
273.15
Offset
+
(
)
–
=