Digilent DMC60C Довідковий посібник - Сторінка 7

Переглянути онлайн або завантажити pdf Довідковий посібник для Контролер Digilent DMC60C. Digilent DMC60C 15 сторінок.

Valid CAN Control Frame received

within the last 100ms. The specified

control mode resulted in a Negative

Duty Cycle being Motor Output

5 Brake / Coast Mode

The DMC60C's response when a neutral duty cycle is applied to the output depends on the

Brake/Coast setting. When the DMC60C is configured for Brake Mode, the M+ and M- leads are

internally shorted when a neutral duty cycle is applied to the output, which causes an attached motor

to resist rotation. If an attached motor is spinning, then its speed decreases at a much quicker rate

than it would if the M+ and M- leads were allowed to float. When configured for Coast Mode, the M+

and M- leads float when a neutral duty cycle is applied to the output.

The current Brake/Coast setting is displayed by the Brake/Coast CAL LED, which is in the center of

the triangle located at the center of the housing. When the device is operating in Brake Mode, the

LED is illuminated Red. When the device is operating in Coast Mode, the LED is off. The

Brake/Coast setting can be toggled by pressing down on the center of the triangle, then releasing

the button.

The Brake/Coast setting is stored in non-volatile memory and is re-stored automatically after power

cycles.

When the DMC60C is connected to a CAN bus the Brake/Coast setting may be overridden by the

CAN control frame. When the Brake/Coast override is active the Brake/Coast CAL LED is overridden

to display the setting specified by the CAN control frame. During this time the DMC60C employs the

Brake/Coast mode that is specified in the CAN frame when applying the neutral duty cycle to the

output.

6 Input Signal Calibration

The DMC60C accepts PWM input signals with a positive pulse width between 0.6 and 2.4

milliseconds. Due to variations in controllers, it may be necessary to adjust, or calibrate, the pulse

widths that correspond to the maximum forward and reverse duty cycles, as well as the neutral input.

To perform calibration, follow these steps:



1. Press and hold the Brake/Coast CAL button. After approximately 5 seconds, the top and

bottom LEDs will begin to alternate between Blue and Off. This indicates that calibration has

started.



2. While continuing to hold the button, use the controller to move between full forward and

full reverse (perhaps by moving a joystick), making sure to reach both extremes. This may

be repeated more than once, but there is no required minimum.

LEDs blink Red in a counter-clockwise circular pattern

(LED1 → LED4 → LED3 → LED2 → LED1). The LED

update rate is proportional to the duty cycle of the output

and increases with increased duty cycle. At 100% duty

cycle, all 4 LEDs are illuminated Red.