NI 9775 (FPGA Interface)

NI CompactRIO Device Drivers Help

Edition Date: December 2017

Part Number: 373197L-01

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CompactRIO 4-Ch, ±10 V, 20 MS/s, 14-Bit Digitizer

FPGA I/O Node

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

Note  You can synchronize an NI 9775 module with other modules that have a selectable timebase source.
Note  You can only use the 12.8 MHz exported clock of the NI 9469 as the reference clock of the NI 9775. You cannot use the 13.1072 MHz clock with the NI 9775.
Note  You can only use another NI 9775 or the NI 9469 configured to export its clock as the reference clock for the NI 9775.

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 9775 has AI channels 0 to 3.
Caution Caution  Do not access AI channels on multiple modules from the same FPGA I/O Node if the modules are not synchronized or do not use the same data rate.
Reference Clock Gives access to the reference clock in the LabVIEW block diagram. Export the onboard clock of the NI 9775 and use the FPGA I/O Node in a single-cycle timed loop to access this channel.
Start Controls when the NI 9775 starts acquiring data.
Stop Controls when the NI 9775 stops acquiring data. When the 9775 is acquiring data, you must write TRUE to this channel before you can access properties of the module.

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 methods for this device.

Method Description
Fetch Record Data Fetches the next available sample from each channel in the Triggered Records. Updates the number of remaining elements of the current record, and the number of remaining records. This method cannot be executed at the same time as the AIx I/O node or any of the Trigger Record Method Nodes.
  • Records Remaining—Indicates the number of records available to be fetched from the module.
  • Elements Remaining—Indicates the number of samples available to be fetched from the current record.
  • Timeout—Specifies the minimum number of ticks the Method Node waits before timing out. The Method Node times out if the data is not yet available to access. Set this parameter to -1 if you want the Method Node to wait indefinitely.
Trigger Record on HW Event Triggers a record event whenever a hardware event occurs on a single channel. Any hardware event that occurs outside of this execution will be lost. Once there are no more records available to trigger, you cannot send any more triggers.
  • AI Channel—Specifies which input channel the hardware event will come from.
  • Trigger Slope—Specifies the slope direction of the hardware event. Can be either "Positive" or "Negative".
  • Trigger Level—Specifies the voltage level used to trigger a record.
  • Hysteresis Value—Specifies the hysteresis value for the trigger. If the Trigger Slope is positive, the Hysteresis Value will be below the Trigger Level. If the Trigger Slope is negative, the Hysteresis Value will be above the Trigger Level.
  • Timeout—Specifies the minimum number of ticks the Method Node waits before timing out. The Method Node times out if the module cannot be triggered or if the hardware event condition has not been met. Set this parameter to -1 if you want the Method Node to wait indefinitely. The hardware event may be missed if timeout is set to a small number of ticks.
Trigger Record On HW Event (Multiple Sources) Triggers a record event whenever a hardware event occurs on any channel. Any hardware event that occurs outside of this execution will be lost. Once there are no more records available to trigger, you cannot send any more triggers.
  • Trigger Configuration—Specifies the trigger configurations for each channel. Each of these contains the following channels: Enable, Trigger Slope, Trigger Level, and Hysteresis Value.
  • Timeout—Specifies the minimum number of ticks the Method Node waits before timing out. The Method Node times out if the module cannot be triggered or if the hardware event condition has not been met. Set this parameter to -1 if you want the Method Node to wait indefinitely. The hardware event may be missed if timeout is set to a small number of ticks.
Trigger Record Signals the module to trigger a record. Once there are no more records available to trigger, you can not send any more triggers.
  • Timeout—Specifies the minimum number of ticks the Method Node waits before timing out. The Method Node times out if the module cannot be triggered. Set this parameter to -1 if you want the Method Node to wait until the module can trigger. Set this parameter to 0 if you want the Method Node to trigger immediately if there is not already already a record being acquired.

I/O Properties

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

Property Description
Enable Analog Filter Changes the configuration of the analog filter
LSB Weight (High-Resolution) Returns the LSB weight in nV/LSB.
LSB Weight (High-Speed, Analog Filter Disabled) Returns the LSB weight in nV/LSB.
LSB Weight (High-Speed, Analog Filter Enabled) Returns the LSB weight in nV/LSB.
Offset (High-Resolution) Returns the calibration offset in µV.
Offset (High-Speed, Analog Filter Disabled) Returns the calibration offset in µV.
Offset (High-Speed, Analog Filter Enabled) Returns the calibration offset in µV.

Module Properties

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

Property Description
Module ID Returns the Module ID, 0x7889.
Serial Number Returns the unique serial number of the module.
Vendor ID Returns the NI vendor ID, 0x1093.
Record Data Rate Specifies the rate at which the module acquires data for the Record Acquisition.
Record Pre-Trigger Samples Specifies the number of acquired samples prior to the trigger of a record.
Continuous Data Rate Specifies the rate at which the module acquires data in continuous mode.
Records Available to Fetch Returns the number of records available to fetch in the module.
Records Available to Trigger Returns the number of records available to trigger in memory.
Total Record Samples Specifies the number of samples per record.
Timing Mode Changes the module configuration between High-Speed and High-Resolution

Single-Cycle Timed Loop

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

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