DC541_PWM_FAST

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Parameter Value
Library_File_Name DC541_PWM_AC500_V22.lib
Firmware V1.12
Type Type_Function_Block_History
Available as of PLC runtime system V2.2

The block DC541_DAMPENER transfers all values to control the PWM functionality for DC541 device.

If the device is configured in PWM-mode, all 8 outputs are controlled by PWM functionality (Pulse-width Modulation).

All 8 outputs are switched on with the same frequency, at the same start time, but with different duration.

The duration is adjusted with the block DC541_PWM_FAST with values for ON_DURx.

The following rule has to be applied:

  • ON_DURx < PERIOD

All input parameters can be continuously modified, the values are accepted immediately.

The following values are specified:

  • Minimal length for a single pulse PULSE_WIDTH in microseconds from 40 to 32767
  • Number of pulses for a complete period: PERIOD 2 to 255

The resulting frequency is then calculated as:

f = 1/ (PULSE_WIDTH*PERIOD) with a range from 1/ /(2*4040 to 32767µs) = 12.5 kHz to 1/(255*32767µs) = 0.12 Hz

The device uses an internal counter with a clock PULSE_WIDTH µs which counts from 0 to PERIOD.

When the condition ON_DURx = counter is reached, the respective output is switched on, off otherwise.

All outputs with ON_DURx>0 are switched on at the same.

The following sequence would be achieved with:

  • PULSE_WIDTH= 50, PERIOD=10, ON_DUR0=6 (SIGNAL0) and ON_DUR1=4 (SIGNAL1) or
  • PULSE_WIDTH= 100, PERIOD=5, ON_DUR0=3 and ON_DUR1=2
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SIGNAL_PWM