NI 9144 User Guide and Specifications
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© National Instruments
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NI 9214 Conversion Speed Control/Open Thermocouple Detection (0x2002)
The NI 9214 can convert at two pre-defined rates, as controlled by the speed control field. Note
that the conversion rate assumes that 20 channels are in the scan list. The NI 9214 can also
enable/disable open thermocouple detection.
NI 9214 Common Mode Error/Status (0x2003)
The error/status field is defined as shown in Table 36 and Table 37.
NI 9214 Scan List
The scan list is a simple list of channels to convert, in order. The NI 9214 has 20 total channels
that can be measured:
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0..15: 16 thermocouple channels (always measured in a ±78.125 mV range)
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16: One auto zero channel (always measured in a ±78.125 mV range)
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17: Cold junction channel 0 (always measured in a ±2.5 V range)
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18: Cold junction channel 1 (always measured in a ±2.5 V range)
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19: Cold junction channel 2 (always measured in a ±2.5 V range)
Table 35.
NI 9214 Conversion Speed Control/Open Thermocouple Detection
Bits
Field
31..5
Reserved
4
Open Thermocouple Detection:
0x10: Enable
0x00: Disable
3:0
Conversion Speed Control:
0x02: High-Accuracy, 52 ms/channel (1.04 s total)
0x0F: High-Speed, 735 µs/channel (14.7 ms total)
Table 36.
NI 9214 Open Thermocouple Status Code
Bits
Field
31..16
Reserved
15..0
The latest detected open thermocouple status. Each channel takes one bit.
Table 37.
NI 9214 Common Mode Voltage Error Code
Bits
Field
31..16
Reserved
15..0
The latest detected common mode voltage error. Each channel takes one bit.
