Load PWM Duty Cycle

NI-Motion VI

Load PWM Duty Cycle

Sets the duty cycle for a PWM output.

Details

Device Compatibility

DeviceCompatibility
7330
Y
7340
Y
7344
Y
7350
Y
7390
N
NI SoftMotion Controller for CANopen—Accelnet
N
NI SoftMotion Controller for CANopen—Xenus
N
Duty Cycle (0) is a value between 0 and 255 that specifies the amount of time the PWM output is high.
Board ID is a unique number assigned by Measurement & Automation Explorer (MAX) used to send and receive commands and data to or from a specific NI motion controller.
PWM Output selects the PWM Output to configure (1 or 2).
Inp Vect indicates the source of the data for this VI. Available input vectors include immediate (0xFF), variable (0x01 through 0x78), or indirect variable (0x81 through 0xF8). Refer to Input and Return Vectors for more detailed information.
error in (no error) describes error conditions that occur before this VI runs. The default input of this cluster is no error. If an error already occurred, this VI returns the value of error in in error out. The VI runs normally only if no incoming error exists. Otherwise, the VI passes the error in value to error out. The error in cluster contains the following parameters:
status is TRUE if an error occurred before this VI was called, or FALSE if not. If status is TRUE, code is a nonzero error code. If status is FALSE, code is zero or a warning code.
code is a number identifying an error or warning. If status is TRUE, code is a nonzero error code. If status is FALSE, code is zero or a warning code. Use the error handler VIs to look up the meaning of this code and display the corresponding error message.
source is a string that indicates the origin of the error, if any. Typically, source is the name of the VI in which the error occurred.
Bd ID Out is provided for flow control. You can string together NI-Motion VIs by wiring the Bd ID Out terminal of one VI to the Board ID terminal of the next VI.
Resource Out is the Axis, Vector Space, ADC, or Encoder you wired into the VI. Use Resource Output to pass the resource to another VI and/or to display information about the device.
error out contains error information. If error in indicates an error, error out contains the same error information. Otherwise, it describes the error status that this VI produces.
status is TRUE if an error occurred, or FALSE if not. If status is TRUE, code is a nonzero error code. If status is FALSE, code is zero or a warning code.
code is a number identifying an error or warning. If status is TRUE, code is a nonzero error code. If status is FALSE, code is zero or a warning code. Use the error handler VIs to look up the meaning of this code and display the corresponding error message.
source is a string that indicates the origin of the error, if any. Typically, source is the name of the VI in which the error occurred.

Using This VI

The Duty Cycle determines the amount of time the PWM output is high. A Duty Cycle of 0 corresponds to a 0 V output, and a Duty Cycle of 255 corresponds to a pulse train that is high for 255/256 = 99.6% of the time. Use the Configure PWM Output VI to set the frequency of the PWM output signal.

You can set the Duty Cycle before or after configuring a PWM output. By default, the Duty Cycle is 0, so if you call the Configure PWM Output VI to configure a PWM output, the output is low until you set the Duty Cycle differently. If you set the Duty Cycle first, the PWM output reflects this Duty Cycle immediately after calling the Configure PWM Output VI.

Note  If you are doing onboard programming and are using Inp Vect to get the data this VI needs, remember that this VI reads the variables starting at the memory address pointed to by Inp Vect in the following order: PWM Output, Duty Cycle.