MATLAB XPC TARGET 4 - IO Bedienungsanleitung PDF herunterladen (Seite 22)

1 Introduction

1-16

Interactive Hardware Selection Guide lists show relevant I/O types that are

supported. Be sure to use this as a way to minimize the total number of

boards required for your application.

• If a board provides the required characteristics but does not offer enough

channels, consider using multiple boards.

• Once you have found appropriate boards for all the I/O types required for

your application, make sure that the selected base system’s form factor offers

enough room and bus slots. If this is not the case, you may need to consider

bus expanders (for desktop or rack-mount PCs), different form factors, or

similar I/O boards with more channels.

If the supported I/O boards do not include an I/O type needed for your

application or you do not find an I/O board with the required characteristics,

contact your MathWorks sales representative to discuss alternatives.

Proceed to the final step, which consists of selecting the CPU class according to

your performance needs. See “Selecting the CPU” on page 1-16.

Selecting the CPU

The last major step in the hardware selection process is to choose the

appropriate CPU class for your application. This section presents guidelines to

help you estimate if the overall system performance is sufficient for your

application.

Your real-time application runs at a certain base sample time derived from the

dynamic characteristics of your application. The overall performance for the

target system must be sufficient to execute within the base sample time

without overloading the CPU. However, the overall performance is not simply

determined by the complexity of the Simulink and Stateflow models, but also

the I/O complexity, since each channel of I/O introduces latencies to the target

application. This section discusses these two components to help you quantify

their effect on the system performance.

xPC Target is a high performance, real-time prototyping environment that

allows smaller applications to execute with a base sample time of 20

μs on

high-performance CPUs, such as the Athlon or Pentium III. According to our

benchmarks, the Pentium 4 architecture seems to be less effective for

floating-point intensive applications. As the application and I/O grow in size

and complexity, the achievable minimal base sample time also increases. It is

1 2 ... 17 18 19 20 21 22 23 24 25 26 27 ... 51 52

Keine Kommentare

MATLAB XPC TARGET 4 - IO Bedienungsanleitung Seite 22