Operation mode "PWM, Period"
Function and settings
- This mode allows the duty cycle and the period value (A) to be changed quickly in a real-time context.
- The following additional settings are possible
Fig.141: EL2502-0010 - CoE and process data for Predefined PDO Assignment "PWM, Period"- 0x70n0:11 "PWM output":
The percentage duty cycle (Duty cycle: TON / T) is specified in "PWM output" [0 ... 100 %] to change the pulse-pause ratio. The pulse-pause TOFF is calculated automatically as the difference to the 100 % pulse value.
Desired pulse-pause ratio(Duty cycle) | Value range in hex | Value range in dec |
|---|---|---|
100 % | 7FFF | 32767 |
50 % | 3FFF | 16383 |
0 % | 0 | 0 |
- 0x70n0:12 "PWM period":
Specification of the PWM period in µs (corresponds to a frequency specification).
The resolution of the output signal depends on the frequency or period value specification.
The valid value range in this mode corresponds to:
Output frequency: min. approx. 20 Hz, max. 300 kHz - The number of steps changes depending on the set frequency. The resolution decreases with decreasing period value or increasing PWM frequency.
The resolution or step size can be read in CoE object 0x80nE:01 "Timer resolution".
After changing the PWM values (0x70n0:11 "PWM output" and 0x70n0:12 "PWM period"), the changed PWM output only takes place after the current period has been completed.
Further Information