AN1948_D Freescale Semiconductor / Motorola, AN1948_D Datasheet - Page 11

• Manufacturer Part Number: AN1948_D
• Description: Real Time Development of MC Applications using the PC Master Software Visualization Tool
• Manufacturer: Freescale Semiconductor / Motorola

Freescale Semiconductor, Inc.
Development of Motor Control Applications Using PC Master Software
The speed controller is a Proportional-Integrational type (PI controller) that evaluates the required
speed (
) and the actual speed (
). According to the speed error (
), it generates the
required
actual
error
desired output duty cycle. The Scope window shows the required speed and the actual speed as the
input variables, as well as output duty cycle as the output variable of the controller (see
Figure
4-5).
The response of the system to the change of the motor load is displayed. The Variables window
enables on-line change of the individual parameters of the PI controller. The developer can easily
evaluate the response of the system and tune the controller parameters to get the optimal system
performance.
4.4 On-line Setting of Application Parameters and Variables
The development of an application often requires setting the application parameters and variables
on-line and evaluating the application behavior.
Since PC master software allows the changing of any variable in the memory of the target processor,
the task is pretty easy. The developer can read and modify any variable in processor memory. Since
any memory variable can be changed, the developer is fully responsible for changing only the
variables that do not cause the system damage. The response of the system can be observed either in
the Variables window, or with the Scope or Recorder tool.
PC master software allows the simulation of a the selected variable in the time domain using
Stimulator. The Stimulator updates the selected variable automatically according to the table. The
stimulated variable is predefined in a simple table as a function of time (see
Figure
4-6).
Figure 4-7
illustrates the stimulation of the desired speed and the drive response. The developer can easily
evaluate the response of the system to the change of the variable according to a predefined profile.
Figure 4-6. Setting of Speed Stimulator
As it was mentioned in the PC master software description, the variable can be transformed from the
real-type into more meaningful physical variable. Thus a fractional number from the target processor
can be easily transformed into RPM (speed variables), Volts, Amps, degrees, etc. PC master software
also allows the enumeration of the variables. It is useful for displaying the status of the application or
algorithm. For examples of the real type transformation and the enumeration, look at the variables
listed in the Variable window in
Figure
4-7.
MOTOROLA
Real Time Development using the PC Master Software
11
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