NI 9214 (FPGA Interface)

NI CompactRIO Device Drivers Help

Edition Date: December 2017

Part Number: 373197L-01

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CompactRIO 16-Channel, ±78 mV, 24-Bit Thermocouple Input Module

FPGA I/O Node

You can use an FPGA I/O Node, configured for reading, with this device.

Terminals in Software

Use the FPGA I/O Node to access the following terminals for this device.

Terminal Description
TCx Thermocouple input channel x, where x is the number of the channel. The NI 9214 has TC channels 0 to 15.
Autozero Autozero channel. For the best accuracy, read the Autozero channel in the same FPGA I/O Node as the thermocouple input channels.
CJCx Cold-junction compensation channel x, where x is the number of the channel. The NI 9214 has CJC channels 0 to 2. For the best accuracy, read the appropriate CJC channel in the same FPGA I/O Node as the corresponding thermocouple input channels. You must convert the CJC data to temperature.
  • CJC 0—corresponds to thermocouple input channels TC2, TC3, TC4, TC7, TC8, and TC9.
  • CJC 1—corresponds to thermocouple input channels TC10, TC11, TC12, TC13, TC14, and TC15.
  • CJC 2—corresponds to thermocouple input channels TC0, TC1, TC5, and TC6.

Arbitration

This device supports only the Arbitrate if Multiple Requestors Only option for arbitration. You cannot configure arbitration settings for this device.

I/O Methods

This device does not support any I/O methods.

Module Methods

Use the FPGA I/O Method Node to access the following module method for this device.

Method Description
Check Cached Status Returns Booleans for each channel that indicate whether the channel was out of range or had an open thermocouple since the last execution of the Check Cached Status method. When the FPGA I/O Node reads the channels, the FPGA VI determines the state of the channels and caches any TRUE value until the Check Cached Status method executes.
  • Force Status Read—When the value of this input is FALSE, the method returns the cached status information since the last time that the Check Cached Status method executed. When the value is TRUE, the method forces the FPGA I/O Node to read all channels and update the status information. Forcing a status read can introduce jitter into an analog input loop.
  • Out of Range—Returns an array of Boolean values. A value of TRUE in any index indicates that the channel sharing a number with that index exceeded the common-mode voltage range at some point after the last time that the Check Cached Status method executed.
  • Open—Returns an array of Boolean values. A value of TRUE in any index indicates that the channel sharing a number with that index detected an open thermocouple on the channel at some point after the last time that the Check Cached Status method executed.

I/O Properties

This device does not support any I/O properties.

Module Properties

Use the FPGA I/O Property Node to access the following module properties for this device.

Property Description
Conversion Time Sets the time it takes to acquire one point of data from one or more channels in a single FPGA I/O Node. You can select High Speed or High Resolution. Refer to the NI 9214 with NI TB-9214 Operating Instructions and Specifications for more information about the High Speed and High Resolution conversion times. This property overwrites the value you configure in the C Series Module Properties dialog box.

Returns the conversion time setting when configured to read.
Open TC Detection Enable Enables open thermocouple detection on the module. When this property is enabled, the NI 9214 returns an error if it detects an open thermocouple on any TCx channel. This property overwrites the value you configure in the C Series Module Properties dialog box.

Note Note  Enabling open thermocouple detection on the NI 9214 results in a small current leakage in the thermocouple measurement. Refer to the Overview of Open Thermocouple Detection support document for more information about compensating for this error.
Returns open thermocouple detection setting when configured to read.
Module ID Returns the module ID, 0x74EE.
Serial Number Returns the unique serial number of the module.
Vendor ID Returns the NI vendor ID, 0x1093.

Single-Cycle Timed Loop

This device does not support the single-cycle Timed Loop.

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