Introduction

This program provides a simple example of how to run a real-time loop using RTAI's LXRT module.

It was tested on a computer with Linux kernel 2.6.32.20 and RTAI 3.9.

Download

If you have SSH access to github:

$ git clone git@github.com:liangfok/rtai_lxrt_unit_test.git

If you do not have SSH access to github:

$ git clone https://github.com/liangfok/rtai_lxrt_unit_test.git

Build

Execute:

$ cd [directory containing this README]
$ mkdir build
$ cd build
$ cmake ..
$ make

Execute

Load the RTAI kernel modules:

$ cd [directory containing this README]
$ ./scripts/insmods

Ensure the RTAI kernel modules are loaded:

$ lsmod | grep rtai
rtai_shm               11475  0
rtai_sem               25686  0
rtai_lxrt             116422  2 rtai_shm,rtai_sem
rtai_hal               85236  3 rtai_shm,rtai_sem,rtai_lxrt

Run the program:

$ cd [directory containing this README]
$ cd build
$ sudo ./TestRTAI [loop period in seconds]

Typically, you will want a loop period of 0.001 (1 ms).

You should see the actual loop period being printed to the screen. Here is an example:

TestRTAI::rtmethod: Period = 0.999825ms
TestRTAI::rtmethod: Period = 0.999971ms
TestRTAI::rtmethod: Period = 1.00002ms
TestRTAI::rtmethod: Period = 1.00002ms
TestRTAI::rtmethod: Period = 0.999975ms
TestRTAI::rtmethod: Period = 1.00001ms
TestRTAI::rtmethod: Period = 0.999979ms
TestRTAI::rtmethod: Period = 1.00018ms
TestRTAI::rtmethod: Period = 0.99983ms
TestRTAI::rtmethod: Period = 1.00001ms
TestRTAI::rtmethod: Period = 0.999975ms
TestRTAI::rtmethod: Period = 1.00002ms
TestRTAI::rtmethod: Period = 0.999989ms
TestRTAI::rtmethod: Period = 1ms

Type any key to stop the program.

Finally, unload the RTAI kernel modules:

$ cd [directory containing this README]
$ ./scripts/rmmods