AN1857 Freescale Semiconductor / Motorola, AN1857 Datasheet - Page 31

• Manufacturer Part Number: AN1857
• Description: A 3-Phase ac Induction Motor Control System Based on the MC68HC908MR32
• Manufacturer: Freescale Semiconductor / Motorola

System Software
AN1857
MOTOROLA
Variables read by the PC-Master software as a default and displayed to
the user are:
For the latest information regarding the PC-Master software, refer to the
Motorola, Semiconductor Products Sector, Motor Control web page:
http://motorola.com/semiconductors/motor.
For the latest application note software, refer to the following web links:
http://www.mcu.motsps.com/dev_tools/appsw.html
http://motorola.com/semiconductors/motor
http://motorola.com/semiconductors
The motor drive can be controlled in two ways.
The motor control software monitors the state of the sensors as they are
periodically scanned in the software timer loop, while the speed of the
motor is calculated utilizing the input capture interrupt. Whenever the
motor is running, a green LED located on the control board will
illuminate. According to the operational mode setup and state of the
control signals (start/stop switch, forward/reverse switch, speed
potentiometer), the speed command is calculated using an
acceleration/deceleration ramp. The comparison between the actual
speed command and the tachometer speed generates a speed error.
The speed error is passed to the speed PI controller generating a new
corrected motor frequency. Using a V/Hz ramp, the corresponding
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Freescale Semiconductor, Inc.
For More Information On This Product,
Required speed
Actual motor speed
dc bus voltage
Power module temperature
Display system status and error flags
In the manual operation mode, speed is set by the potentiometer,
start/stop and forward/reverse controls are mounted on the control
board.
In the PC-Master mode of operation, all motor drive control is
performed from commands from a PC connected to the control
board.
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Application Note
Software
31