NI 9251 (FPGA Interface)

NI CompactRIO Device Drivers Help

Edition Date: December 2017

Part Number: 373197L-01

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FPGA I/O Node

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

Note  You can synchronize an NI 9251 module with other modules that have a selectable timebase source.

Terminals in Software

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

Terminal	Description
AIx	Analog input channel x, where x is the number of the channel. The NI 9251 has channels 0 to 1.
Onboard Clock	Gives access to the onboard clock in the LabVIEW block diagram. The onboard clock frequency is 13.1072 MHz. Use the FPGA I/O Node in a single-cycle timed loop to access this channel. You must export the onboard clock of the NI 9251 to access this channel.
Start	Channel that controls when the NI 9251 starts acquiring data. If TRUE is written to the Start channel, the NI 9251 starts acquiring data. When the NI 9251 is acquiring data, you must write TRUE to the Stop channel before you can access properties for the module. If FALSE is written to the Start channel, no operation is performed.
Stop	Channel that controls when the NI 9251 stops acquiring data. If TRUE is written to the Stop channel, the NI 9251 stops acquiring data. When the NI 9251 is acquiring data, you must write TRUE to the Stop channel before you can access properties for the module. If FALSE is written to the Stop channel, no operation is performed.

Arbitration

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

I/O Properties

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

Property	Description
Input Configuration	Sets the input configuration of the corresponding channel to one of two modes: AC Coupled; DC Coupled.

Module Properties

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

Property	Description
Data Rate	Sets the rate at which the NI 9251 acquires data.
Module ID	Returns the module ID, 0x77E9.
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.