Specifying the period | “PWM period” process data value

The period of the output can be specified, which corresponds to a frequency setting. The period is specified using the “PWM period” process data value in units of 1 µs.

The resolution of the output signal depends on the specified frequency or period. This can be read for each channel in index 0x80nE:01, “Timer resolution”.

The following table shows the valid range of values based on the selected ModuleIdent.

ModuleIdent

Description

Valid value range for “PWM period”

0x809C8

PWM, Output Pulse Width, Period (INT16 Legacy)

10hex (16dec)

16 µs corresponds to 62.5 kHz

FFFFhex (65,535dec)

65.565 ms corresponds to 15 Hz

0x3809C8

PWM, Output Pulse Width, Period (INT32 Legacy)

10hex (16dec)

16 µs corresponds to 62.5 kHz

F4240hex (1,000,000dec)

1 s corresponds to 1 Hz

The following table shows examples for setting the period (1/frequency) within the valid value range.

Desired period (frequency)

Setting via the “PWM period” process data value

1,000,000 µs (1 Hz)

F4240hex

1,000,000dec

50,000 µs (20 Hz)

C350hex

50,000dec

10,000 µs (100 Hz)

2710hex

10,000dec

1,000 µs (1 kHz)

03E8hex

1,000dec

16 µs (62.5 kHz)

10hex

16dec

Notice

Specifying invalid period values

If the specified period values are outside the valid output range

  • the specification is rejected,
  • a diagnostic message is output:
    0x461A “Slot Group n: Invalid frequency/period written”,
  • the maximum permissible value is output.