Asynchronous I/O and PID Control with Compact RIO

Downloads

Filename: asynchio_8.x.zip
Requirements: View

Filename: asynchio.zip
Requirements: View

This example illustrates the use of asynchronous input and output operations between the FPGA and host controller on an embedded CompactRIO system. In asynchronous operations the input and output operations run independently of the host application. The host application reads input values from the FPGA and updates output values at its own rate. Some input values may be lost or the same acquired value may be read more than one time by the host depending on the relative loop rates of the FPGA and host application.

The example includes three different host applications.

- A simple asynchronous host which just reads and writes the I/O values

- A PID asynchronous host which inserts a PID algorithm between the analog input and output. The input values are used as the process variables for the PID, while the PID outputs are written to the analog outputs.

- A host application which enables the interrupt generation on the FPGA VI. The host application is synchronized with the FPGA VI using the interrupts coming from the FPGA. For each interrupt that is detected, the input and output values are updated on the FPGA.


Note: The analog input and output values in this example are not fully calibrated. To make a fully calibrated measurement read the LSB Weight and Offset calibration values from the CompactRIO module for each analog input and output channel and use the conversion VIs provided with the CompactRIO examples in LabVIEW for the modules (9215 and 9263 in this example) you are using.

Note: While this example uses a specific cRIO controller, chassis/backplane and set of modules, it can easily be edited for other chassis/backplanes and modules or to run on a R series RIO device (PCI/PXI-7831R).

Requirements

Filename: asynchio_8.x.zip

Software Requirements:


Application Software: LabVIEW Professional Development System 8.0
Toolkits and Add-Ons: LabVIEW Real-Time Module 8.0, LabVIEW FPGA Module 8.0

Hardware Requirements:


Hardware Group: CompactRIO, Real-Time (RT), Reconfigurable I/O (RIO)
Driver: NI-RIO 2.0
Filename: asynchio.zip

Software Requirements:


Application Software: LabVIEW Full Development System 7.1
Toolkits and Add-Ons: LabVIEW FPGA Module 1.1, LabVIEW Real-Time Module 7.1
Language(s): LabVIEW

Hardware Requirements:


Hardware Group: CompactRIO
Hardware Model: cRIO-9002, NI 9215, NI 9263, NI 9411, NI 9474
Driver: NI-RIO 1.3, NI-VISA 3.2