DAQmx Timing Properties

DAQmx - Data Acquisition VIs and Functions

Edition Date: January 2019

Part Number: 370469AP-01

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Use the DAQmx Timing properties to configure the sample timing and duration of a task.

PropertyDescription
Sample Quantity:Sample Mode Specifies if a task acquires or generates a finite number of samples or if it continuously acquires or generates samples. Details
Sample Quantity:Samples Per Channel Specifies the number of samples to acquire or generate for each channel if SampQuant.SampMode is Finite Samples. If SampQuant.SampMode is Continuous Samples, NI-DAQmx uses this value to determine the buffer size. Details
Sample Timing Type Specifies the type of sample timing to use for the task. Details
Sample Clock: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. Details
Sample Clock:Maximum Rate Indicates the maximum Sample Clock rate supported by the task, based on other timing settings. For output tasks, the maximum Sample Clock rate is the maximum rate of the DAC. For input tasks, NI-DAQmx calculates the maximum sampling rate differently for multiplexed devices than simultaneous sampling devices. Details
Sample Clock:Source Specifies the terminal of the signal to use as the Sample Clock. Details
Sample Clock:Active Edge Specifies on which edge of a clock pulse sampling takes place. This property is useful primarily when the signal you use as the Sample Clock is not a periodic clock. Details
Sample Clock:Overrun Behavior Specifies the action to take if Sample Clock edges occur faster than the device can handle them. Details
Sample Clock:Underflow Behavior Specifies the action to take when the onboard memory of the device becomes empty. In either case, the sample clock does not stop. Details
Sample Clock:Timebase Divisor Specifies the number of Sample Clock Timebase pulses needed to produce a single Sample Clock pulse. Details
Sample Clock:Terminal Indicates the name of the internal Sample Clock terminal for the task. This property does not return the name of the Sample Clock source terminal specified with SampClk.SrcDetails
Sample Clock:Timebase:Rate Specifies the rate of the Sample Clock Timebase. Some applications require that you specify a rate when you use any signal other than the onboard Sample Clock Timebase. NI-DAQmx requires this rate to calculate other timing parameters. Details
Sample Clock:Timebase:Source Specifies the terminal of the signal to use as the Sample Clock Timebase. Details
Sample Clock:Timebase:Active Edge Specifies on which edge to recognize a Sample Clock Timebase pulse. This property is useful primarily when the signal you use as the Sample Clock Timebase is not a periodic clock. Details
Sample Clock:Timebase:Master Timebase Divisor Specifies the number of pulses of the Master Timebase needed to produce a single pulse of the Sample Clock Timebase. Details
Sample Clock:Timebase:Terminal Indicates the name of the internal Sample Clock Timebase terminal for the task. This property does not return the name of the Sample Clock Timebase source terminal specified with SampClk.Timebase.SrcDetails
Sample Clock:Digital Filter:Enable Specifies whether to apply the pulse width filter to the signal. Details
Sample Clock:Digital Filter:Minimum Pulse Width Specifies in seconds the minimum pulse width the filter recognizes. Details
Sample Clock:Digital Filter:Timebase:Source Specifies the input terminal of the signal to use as the timebase of the pulse width filter. Details
Sample Clock:Digital Filter:Timebase:Rate Specifies in hertz the rate of the pulse width filter timebase. NI-DAQmx uses this value to compute settings for the filter. Details
Sample Clock:Digital Synchronization:Enable Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device. Details
Sample Clock:Write Waveform:Use Initial Waveform dt Specifies that the value of SampClk.Rate will be determined by the dt component of the initial DAQmx Write waveform input for Output tasks. Details
Handshake:Delay After Transfer Specifies the number of seconds to wait after a handshake cycle before starting a new handshake cycle. Details
Handshake:Start Condition Specifies the point in the handshake cycle that the device is in when the task starts. Details
Handshake:Sample Input Data When Specifies on which edge of the Handshake Trigger an input task latches the data from the peripheral device. Details
Change Detection:Digital Input:Rising Edge Physical Channels Specifies the names of the digital lines or ports on which to detect rising edges. The lines or ports must be used by virtual channels in the task. You also can specify a string that contains a list or range of digital lines or ports. Details
Change Detection:Digital Input:Falling Edge Physical Channels Specifies the names of the digital lines or ports on which to detect falling edges. The lines or ports must be used by virtual channels in the task. You also can specify a string that contains a list or range of digital lines or ports. Details
Change Detection:Digital Input:Tristate Specifies whether to tristate lines specified with ChangeDetect.DI.RisingEdgePhysicalChans and ChangeDetect.DI.FallingEdgePhysicalChans that are not in a virtual channel in the task. If you set this property to TRUE, NI-DAQmx tristates rising/falling edge lines that are not in a virtual channel in the task. If you set this property to FALSE, NI-DAQmx does not modify the configuration of rising/falling edge lines that are not in a virtual channel in the task, even if the lines were previously tristated. Set this property to FALSE to detect changes on lines in other tasks or to detect changes on output-only lines. Details
On Demand:Simultaneous Analog Output Enable Specifies whether to update all channels in the task simultaneously, rather than updating channels independently when you write a sample to that channel. Details
Implicit:Underflow Behavior Specifies the action to take when the onboard memory of the device becomes empty. Details
More:AI Convert:Active Devices Specifies a subset of devices in the task to configure. NI-DAQmx configures all devices in the task if you do not set this property. Details
More:AI Convert:Rate Specifies in Hertz the rate at which to clock the analog-to-digital converter. This clock is specific to the analog input section of multiplexed devices. Details
More:AI Convert:Maximum Rate Indicates the maximum convert rate supported by the task, given the current devices and channel count. Details
More:AI Convert:Source Specifies the terminal of the signal to use as the AI Convert Clock. Details
More:AI Convert:Active Edge Specifies on which edge of the clock pulse an analog-to-digital conversion takes place. Details
More:AI Convert:Timebase Divisor Specifies the number of AI Convert Clock Timebase pulses needed to produce a single AI Convert Clock pulse. Details
More:AI Convert:Timebase:Source Specifies the terminal of the signal to use as the AI Convert Clock Timebase. Details
More:AI Convert:Delay From Sample Clock:Delay Units Specifies the units of DelayFromSampClk.DelayDetails
More:AI Convert:Delay From Sample Clock:Delay Specifies the amount of time to wait after receiving a Sample Clock edge before beginning to acquire the sample. This value is in the units you specify with DelayFromSampClk.DelayUnitsDetails
More:AI Convert:Digital Filter:Enable Specifies whether to apply a digital filter to the AI Convert Clock. Details
More:AI Convert:Digital Filter:Minimum Pulse Width Specifies in seconds the minimum pulse width the filter recognizes. Details
More:AI Convert:Digital Filter:Timebase:Source Specifies the terminal of the signal to use as the timebase of the digital filter. Details
More:AI Convert:Digital Filter:Timebase:Rate Specifies in hertz the rate of the digital filter timebase. NI-DAQmx uses this value to compute settings for the filter. Details
More:AI Convert:Digital Synchronization:Enable Specifies whether to synchronize recognition of transitions in the signal to the internal timebase of the device. Details
More:Master Timebase:Rate Specifies the rate of the Master Timebase. Details
More:Master Timebase:Source Specifies the terminal of the signal to use as the Master Timebase. On an E Series device, you can choose only between the onboard 20MHz Timebase or the RTSI7 terminal. Details
More:Reference Clock:Rate Specifies the frequency of the Reference Clock. Details
More:Reference Clock:Source Specifies the terminal of the signal to use as the Reference Clock. Details
More:Synchronization Pulse:Type Specifies the type of sync pulse used in the task. Details
More:Synchronization Pulse:Digital Edge:Source Specifies the terminal of the signal to use as the synchronization pulse. The synchronization pulse resets the clock dividers and the ADCs/DACs on the device. Details
More:Synchronization Pulse:Time:When Specifies the start time of the sync pulse. Details
More:Synchronization Pulse:Time:Timescale Specifies the timescale to be used for timestamps for a sync pulse. Details
More:Synchronization Pulse:Synchronization Time Indicates in seconds the delay required to reset the ADCs/DACs after the device receives the synchronization pulse. Details
More:Synchronization Pulse:Minimum Delay To Start Specifies in seconds the amount of time that elapses after the master device issues the synchronization pulse before the task starts. Details
More:Synchronization Pulse:Reset Time Indicates in seconds the amount of time required for the ADCs or DACs on the device to reset. When synchronizing devices, query this property on all devices and note the largest reset time. Then, for each device, subtract the value of this property from the largest reset time and set SyncPulse.ResetDelay to the resulting value. Details
More:Synchronization Pulse:Reset Delay Specifies in seconds the amount of time to wait after the Synchronization Pulse before resetting the ADCs or DACs on the device. When synchronizing devices, query SyncPulse.ResetTime on all devices and note the largest reset time. Then, for each device, subtract the reset time from the largest reset time and set this property to the resulting value. Details
More:Synchronization Pulse:Terminal Indicates the name of the internal Synchronization Pulse terminal for the task. This property does not return the name of the source terminal. Details
More:Synchronization Clock:Interval Specifies the interval, in Sample Clock periods, between each internal Synchronization Clock pulse. NI-DAQmx uses this pulse for synchronization of triggers between multiple devices at different rates. Refer to device documentation for information about how to calculate this value. Details
Advanced:Sample Timing Engine Specifies which timing engine to use for the task. Details
Advanced:First Sample Timestamp:Enable Specifies whether to enable the first sample timestamp. Details
Advanced:First Sample Timestamp:Timescale Specifies the timescale to be used for the first sample timestamp. Details
Advanced:First Sample Timestamp:Value Indicates the timestamp of the first sample. Details
Advanced:First Sample Clock Time:When Specifies the time of the first sample clock pulse. Details
Advanced:First Sample Clock Time:Timescale Specifies the timescale to be used for the value of FirstSampClk.WhenDetails

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