DioSetPwmPulseDuty

Function

Sets the PWM pulse duty cycle for the specified channel.

Format

Ret = DioSetPwmPulseDuty( Id , ChNo , ChNum , PulseDuty )

Parameters

Id [ VB.NET: Short ] [ C, C++: short ] [ C#: short ] [ Python: ctypes.c_short ]
Specify the device ID retrieved from DioInit.

ChNo [ VB.NET: Short ] [ C, C++: short * ] [ C#: out short ] [ Python: ctypes.POINTER(ctypes.c_short) ]
Specify the start address of the array that stores the channel numbers to set.

ChNum [ VB.NET: Short ] [ C, C++: short ] [ C#: short ] [ Python: ctypes.c_short ]
Specify the number of channels specified in ChNo.

PulseDuty [ VB.NET: UShort ] [ C, C++: unsigned short * ] [ C#: out ushort ] [ Python: ctypes.POINTER(ctypes.c_ushort) ]
Specify the start address of the array that stored the PWM pulse duty cycle settings.

PulseDuty sets the ON time.
When the value is 0, the duty cycle is 0%. When the value is 65535, the duty cycle is 100%.

Setting range: 0 to 65535

Return Value

Ret [ VB.NET: Integer ] [ C, C++: long ] [ C#: int ] [ Python: ctypes.c_long ]

Definition	Value [Dec]	Description
DIO_ERR_SUCCESS	0	Normal completed.
DIO_ERR_SYS_RECOVERED_FROM_STANDBY	7	Execute DioResetDevice function because the device has recovered from standby mode.
DIO_ERR_DLL_INVALID_ID	10001	Invalid ID specified.
DIO_ERR_DLL_CALL_DRIVER	10002	Not call the driver (Failure on DEVICE I/O CONTROL).
DIO_ERR_DLL_BUFF_ADDRESS	10100	Invalid data buffer address
DIO_ERR_SYS_NOT_SUPPORTED	20001	This board couldn't use this function.
DIO_ERR_SYS_CH_NO	20105	Channel No. is outside the setting range.
DIO_ERR_SYS_CH_NUM	20106	Channel number is outside the setting range.
DIO_ERR_SYS_PWM_PULSE_DUTY	20902	The PWM pulse duty ratio is out of range.
DIO_ERR_SYS_DEVICE_ERR_DRIVER_IC_ERR	21200	Driver IC error occurred.
DIO_ERR_SYS_DEVICE_ERR_PCOM_FAILURE	21201	PCOM power failure occurred.

The others (See also: Details of Error Code)

Initial Value

Remarks

Sets the PWM pulse duty cycle for the specified channel.

The ON time is determined by the configured PWM pulse period and the value set for PulseDuty.
For details on the PWM pulse period, please refer to the DioSetPwmPulsePeriod function.

Examples of setting the PulseDuty value based on the duty ratio are shown below.

PWM pulse period	Desired Duty ratio	PulseDuty	The ON time (0.1μsec unit)	(Reference) DioSetPwmPulsePeriod
PWM pulse period	Desired Duty ratio	PulseDuty	The ON time (0.1μsec unit)	PulsePeriodValue	PulsePeriodUnit
5.0μsec	0%	0	0.0μsec	5	DIO_PWM_PULSE_PERIOD_UNIT_US
	25%	16384	1.2μsec
	50%	32768	2.5μsec
	75%	49152	3.7μsec
	100%	65535	5.0μsec
250msec	0%	0	0.0μsec	250	DIO_PWM_PULSE_PERIOD_UNIT_MS
	25%	16384	62,500.9μsec
	50%	32768	125,001.9μsec
	75%	49152	187,502.8μsec
	100%	65535	250,000.0μsec
1sec	0%	0	0.0μsec	1	DIO_PWM_PULSE_PERIOD_UNIT_S
	25%	16384	250,003.8μsec
	50%	32768	500,007.6μsec
	75%	49152	750,011.4μsec
	100%	65535	1,000,000.0μsec

To improve the duty cycle setting resolution, the setting range of PulseDuty has been changed from a percentage value (0–100) to a binary value (0–65535). (Released in July 2026)
Please note that updating to the following versions may affect your applications.
  - API-DIO(WDM) Ver.11.10 or later
  - CPSN-MCB271 (Firmware Ver.1.81 or later)
  - CC-USB271 (Firmware Ver.1.32 or later)

Example

Set the duty cycle of channel 0 to 25%(16384) and the duty cycle of channel 1 to 50%(32768).

VB.NET	Dim Ret As Integer Dim ChNo(1) As Short Dim PulseDuty(1) As UShort ChNo(0) = 0 ChNo(1) = 1 PulseDuty(0) = 16384 PulseDuty(1) = 32768 Ret = DioSetPwmPulseDuty( Id , ChNo , 2 , PulseDuty )
C, C++	long Ret; short ChNo[2] unsigned short PulseDuty[2]; ChNo[0] = 0; ChNo[1] = 1; PulseDuty[0] = 16384; PulseDuty[1] = 32768; Ret = DioSetPwmPulseDuty( Id , &ChNo[0] , 2 , &PulseDuty[0] );
C#	int Ret; short[] ChNo = new short[2]; ushort[] PulseDuty = new ushort[2]; ChNo[0] = 0; ChNo[1] = 1; PulseDuty[0] = 16384; PulseDuty[1] = 32768; Ret = dio.SetPwmPulseDuty( Id , out ChNo , 2 , out PulseDuty );
Python	Ret = ctypes.c_long() ChNoType = ctypes.c_short * 2 ChNo = ChNoType() PulseDutyType = ctypes.c_short * 2 PulseDuty = PulseDutyType() ChNo[0] = 0 ChNo[1] = 1 PulseDuty[0] = 16384 PulseDuty[1] = 32768 Ret.value = cdio.DioSetPwmPulseDuty( Id , ChNo , 2 , PulseDuty )