Real-Time Windows Target

Displaying Status Information

Real-Time Windows Target provides the command rtwho for accessing the kernel and displaying status information. It lists information about the version number, kernel performance, and history variables. Also, you can determine whether or not the Real-Time Windows kernel is presently installed:

1. In the MATLAB command window, type

rtwho

MATLAB displays messages similar to those shown below.

Real-Time Windows Target version 2.00 (C) The MathWorks, Inc. 
1994-2000
MATLAB performance = 100.0%
Kernel timeslice period = 1 ms

DRIVERS:                             Name    Address   Parameters
 
                           Humusoft AD512      0x300   []

2. Interpret the message.

This message indicates that MATLAB and other nonreal-time applications (for example, a word processor) are able to run at 100% performance because no real-time applications are currently executing on your PC.

When a real-time application is executing, the MATLAB performance is at a value below 100%. For example, if the MATLAB performance = 90.0%, then the real-time application is using 10% of the CPU time.

We recommend that you select a sample rate so that rtwho returns a MATLAB performance of at least 80%.

The kernel time slice period is the current frequency of the hardware timer interrupt. One millisecond is the maximum value for models with large sample times (slow sampling rate) or when an application has not been built. This value changes when you select sampling times less then one millisecond.

Running the Model rtvdp.mdl

Detecting Excessive Sample Rates