User manual

Using the Microchip Motor Control GUI

The configuration for motion feedback sensors is selectively enabled by selecting the

appropriate check boxes in Feedback Device. When Hall effect sensors alone are

used, the Hall Sensor Phase Angle and MFM Filter Prescaler (Motion Feedback

Module) may be configured; the other options are disabled. When optical encoders are

enabled, the Encoder PPR (Pulses Per Revolution), QEI update mode and MFM

Filter Prescaler may be configured; Hall effect configuration is unavailable. (The use

of the QEI update mode and MFM Filter Prescaler options is discussed in detail in

Section 16 “Motion Feedback Module” of the

“PIC18F2331/2431/4331/4431 Data

Sheet”

(DS39616).

For motors with integrated motion feedback sensors, information on the sensor type

and arrangement is also found in the motor data sheet. External shaft mounted

encoders should also have the required information in their data sheets.

4.5.2 System Parameters

The System Parameters options will vary, depending on the motor control principle

being used by the firmware.

Proportional-Integral-Derivative (PID) systems are most often employed in closed-loop

operation, where constant speed or constant torque is required. Options 1 through 6

will only be available when a PID control algorithm is used.

Acceleration and deceleration are defined as RPS/s for most applications. For

induction motors running in open-loop applications, they are defined as Hz/s.

The Input Voltage is the actual supply voltage to the board. With the drive voltage level

established under Motor Parameters, it is used to calculate the limits on the PCPWM

duty cycle necessary to generate the drive voltage from the input voltage.

The PWM Frequency determines the resolution of the control firmware. The

drop-down combo box presents a fixed range of values depending on the firmware

application and microcontroller.

4.5.3 System Limits

The System Limits reflect the maximums of both the motor and the board being used.

Voltage Limit, or the maximum voltage delivered to the motor, is limited at the input DC

voltage level.

Current Limit is set at the lesser of the maximum current rating for the motor or the

maximum capacity of the board. For the PICDEM MC LV Development Board, this is 4.0A.

Speed Limit is set at the value given in the motor’s data sheet, or at a predetermined

speed set by the particular motor data file.

Note: The Hall effect and optical sensors are mutually exclusive; it is not possible for

some control methods to use both types at once. In these cases, checking the

appropriate box enables all configuration options. Of course, selecting the

None option in Feedback Device disables all sensor configuration options.

Note: The V/F Curve control is not available in the current version of the Motor

Control GUI.

CAUTION

Not all motors may be able to run at the maximum speed defined by the Speed

Limit parameter. It should be regarded as an upper limit and not the motor’s

expected maximum speed.