DAQmx Timing (VI)
- Updated2023-02-21
- 28 minute(s) read
DAQmx Timing (VI)
Owning Palette: DAQmx - Data Acquisition VIs and FunctionsInstalled With: NI-DAQmx
Configures the number of samples to acquire or generate and creates a buffer when needed. The instances of this polymorphic VI correspond to the type of timing to use for the task.
The DAQmx Timing properties include all timing options included in this VI and additional timing options.
Sample Clock
Sets the source of the Sample Clock, the rate of the Sample Clock, and the number of samples to acquire or generate.
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task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically. |
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rate specifies the sampling rate in samples per channel per second. If you use an external source for the Sample Clock, set this input to the maximum expected rate of that clock. |
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source specifies the source terminal of the Sample Clock. Leave this input unwired to use the default onboard clock of the device. |
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active edge specifies on which edges of Sample Clock pulses to acquire or generate samples.
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error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
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sample mode specifies if the task acquires or generates samples continuously or if it acquires or generates a finite number of samples.
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samples per channel specifies the number of samples to acquire or generate for each channel in the task if sample mode is Finite Samples. If sample mode is Continuous Samples, NI-DAQmx uses this value to determine the buffer size. This VI returns an error if the specified value is negative. |
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task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically. |
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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.
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Handshaking
Determines the number of digital samples to acquire or generate using digital handshaking between the device and a peripheral device.
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task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically. |
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error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
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sample mode specifies if the task acquires or generates samples continuously or if it acquires or generates a finite number of samples.
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samples per channel specifies the number of samples to acquire or generate for each channel in the task if sample mode is Finite Samples. If sample mode is Continuous Samples, NI-DAQmx uses this value to determine the buffer size. This VI returns an error if the specified value is negative. |
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task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically. |
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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.
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Burst (Import Clock)
Configures when the DAQ device transfers data to a peripheral device, using an imported sample clock to control burst handshake timing.
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task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically. |
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sample clock rate specifies in hertz the rate of the Sample Clock. |
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sample clock source specifies the source terminal of the Sample Clock. Leave this input unwired to use the default onboard clock of the device. |
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sample clock active edge specifies on which edges of Sample Clock pulses to acquire or generate samples.
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error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
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sample mode specifies if the task acquires or generates samples continuously or if it acquires or generates a finite number of samples.
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samples per channel specifies the number of samples to acquire or generate for each channel in the task if sample mode is Finite Samples. If sample mode is Continuous Samples, NI-DAQmx uses this value to determine the buffer size. This VI returns an error if the specified value is negative. |
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pause when specifies whether the task pauses while the trigger signal is high or low.
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ready for transfer event active level specifies the polarity of the Ready for Transfer Event.
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task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically. |
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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.
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Burst (Export Clock)
Configures when the DAQ device transfers data to a peripheral device, using the onboard Sample Clock of the DAQ device to control burst handshake timing and exporting that clock for use by the peripheral device.
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task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically. |
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sample clock rate specifies in hertz the rate of the Sample Clock. |
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sample clock output terminal specifies the terminal to which to export the Sample Clock. |
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sample clock pulse polarity specifies the polarity of the exported Sample Clock.
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error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
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sample mode specifies if the task acquires or generates samples continuously or if it acquires or generates a finite number of samples.
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samples per channel specifies the number of samples to acquire or generate for each channel in the task if sample mode is Finite Samples. If sample mode is Continuous Samples, NI-DAQmx uses this value to determine the buffer size. This VI returns an error if the specified value is negative. |
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pause when specifies whether the task pauses while the trigger signal is high or low.
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ready for transfer event active level specifies the polarity of the Ready for Transfer Event.
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task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically. |
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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.
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Implicit
Sets only the number of samples to acquire or generate without specifying timing. Typically, you should use this instance when the task does not require sample timing, such as tasks that use counters for buffered frequency measurement, buffered period measurement, or pulse train generation. For finite counter output tasks, samples per channel is the number of pulses to generate.
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task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically. |
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error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
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sample mode specifies if the task acquires or generates samples continuously or if it acquires or generates a finite number of samples.
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samples per channel specifies the number of samples to acquire or generate for each channel in the task if sample mode is Finite Samples. If sample mode is Continuous Samples, NI-DAQmx uses this value to determine the buffer size. This VI returns an error if the specified value is negative. |
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task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically. |
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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.
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Use Waveform
Uses the dt component of the waveform input to determine the Sample Clock rate. dt is the time in seconds between samples. If sample mode is Finite Samples, NI-DAQmx generates the number of samples in the waveform. This VI does not actually generate any samples. You must wire the same waveform to the DAQmx Write VI to generate the samples.
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task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically. |
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waveform is the waveform to use for timing. |
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error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
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sample mode specifies if the task acquires or generates samples continuously or if it acquires or generates a finite number of samples.
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task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically. |
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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.
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Change Detection
Configures the task to acquire samples on the rising and/or falling edges of the lines or ports you specify. To detect both rising and falling edges on a line or port, wire the name of that line or port to both rising edge physical channels and falling edge physical channels.
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task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically. |
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rising edge physical channels specifies the names of the digital lines or ports on which to detect rising edges. The DAQmx physical channel constant lists all lines and ports for devices installed in your system. You also can wire a string that contains a list or range of digital lines or ports to this input. |
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falling edge physical channels specifies the names of the digital lines or ports on which to detect falling edges. The DAQmx physical channel constant lists all lines and ports for devices installed in your system. You also can wire a string that contains a list or range of digital lines or ports to this input. |
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error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
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sample mode specifies if the task acquires samples continuously or if it acquires a finite number of samples.
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samples per channel specifies the number of samples to acquire from each channel in the task if sample mode is Finite Samples. This VI returns an error if the specified value is negative. |
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task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically. |
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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.
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Pipelined Sample Clock
Sets the source of the Sample Clock, the rate of the Sample Clock, and the number of samples to acquire or generate. The device acquires or generates samples on each Sample Clock edge, but it does not respond to certain triggers until a few Sample Clock edges later. Pipelining allows higher data transfer rates at the cost of increased trigger response latency. Refer to the device documentation for information about which triggers pipelining affects.
This timing type allows handshaking using the Pause trigger and either the Ready for Transfer event or the Data Active event. Refer to the device documentation for more information.
This timing type is supported only by the NI 6536 and NI 6537.
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task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically. |
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rate specifies the sampling rate in samples per channel per second. If you use an external source for the Sample Clock, set this input to the maximum expected rate of that clock. |
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source specifies the source terminal of the Sample Clock. Leave this input unwired to use the default onboard clock of the device. |
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active edge specifies on which edges of Sample Clock pulses to acquire or generate samples.
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error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
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sample mode specifies if the task acquires or generates samples continuously or if it acquires or generates a finite number of samples.
|
||||||
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samples per channel specifies the number of samples to acquire or generate for each channel in the task if sample mode is Finite Samples. If sample mode is Continuous Samples, NI-DAQmx uses this value to determine the buffer size. This VI returns an error if the specified value is negative. |
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task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically. |
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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.
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