niHSDIO Read Waveform VI
- Updated2023-02-21
- 29 minute(s) read
Initiates a waveform acquisition on channels enabled for dynamic acquisition, waits to acquire the number of samples specified in samples to read, and returns the acquired data.
Related Topics
1D U32
This instance of niHSDIO Read Waveform returns the data as an array of unsigned 32-bit integers.
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instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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samples to read specifies the number of samples to fetch. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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record to fetch specifies which record you want to fetch from onboard memory. |
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error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
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instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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data returns the acquired waveform. |
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number of samples read returns the number of samples that were successfully acquired and transferred into data. |
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error out contains error information. This output provides standard error out functionality.
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1D U16
This instance of niHSDIO Read Waveform returns the acquired waveform as an array of unsigned 16-bit integers.
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instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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samples to read specifies the number of samples to fetch. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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record to fetch specifies which record you want to fetch from onboard memory. |
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error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
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instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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data returns the data for the waveform. |
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number of samples read returns the number of samples that were successfully acquired and transferred into data. |
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error out contains error information. This output provides standard error out functionality.
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1D U8
This instance of niHSDIO Read Waveform returns the acquired waveform as an array of unsigned 8-bit integers.
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instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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samples to read specifies the number of samples to fetch. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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record to fetch specifies which record you want to fetch from onboard memory. |
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error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
|
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instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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data returns the data for the waveform. |
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number of samples read returns the number of samples that were successfully acquired and transferred into data. |
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error out contains error information. This output provides standard error out functionality.
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WDT
This instance of niHSDIO Read Waveform returns the acquired waveform data from the subset of channels listed in the channel list parameter as a waveform data type. The waveform only contains data from the subset of channels specified in the channel list parameter, not from all of the channels listed in the niHSDIO Assign Dynamic Channels VI, unless you leave the channel list parameter blank.
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instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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timestamp type specifies whether the timestamp for the waveform data is relative or absolute. |
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channel list specifies the channels from which to read waveform data. You must assign all channels that you want to read using the niHSDIO Assign Dynamic Channels VI before selecting those channels with this parameter. NI-HSDIO reads waveform data in the order that you list channels in this parameter, not in the order that those channels are listed in the niHSDIO Assign Dynamic Channels VI. If you leave this parameter blank, NI-HSDIO reads all channels that were set using the niHSDIO Assign Dynamic Channels VI. Specify multiple channels by using a channel list or a channel range. A channel list is a comma (,) separated sequence of channel names (for example, 0,2 specifies channels 0 and 2). A channel range is a lower bound channel followed by a hyphen (-) or colon (:) followed by an upper bound channel (for example, 0-2 specifies channels 0, 1, and 2). |
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samples to read specifies the number of samples to fetch. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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record to fetch specifies which record you want to fetch from onboard memory. |
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error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
|
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instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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data returns the acquired waveform. |
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number of samples read returns the number of samples that were successfully acquired and transferred into data. |
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error out contains error information. This output provides standard error out functionality.
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Multi Bus 1D WDT
This instance of niHSDIO Read Bus Waveform returns the acquired waveform data as an array of waveforms, one for each element in the channel list array. This VI allows you to read data in any order or subset that you desire without the need to manipulate the data after reading it.
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instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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samples to read specifies the number of samples to fetch per waveform. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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channel list specifies the channels from which to read waveform data. You must assign all channels that you want to read using the niHSDIO Assign Dynamic Channels VI before selecting those channels with this parameter. NI-HSDIO reads waveform data in the order that you list channels in this parameter, not in the order that those channels are listed in the niHSDIO Assign Dynamic Channels VI. If you leave this parameter blank, NI-HSDIO reads all channels. Each element in this array, consisting of its specified channels, is output as a single waveform in the data parameter. Specify multiple channels in each element by using a channel list or a channel range. A channel list is a comma (,) separated sequence of channel names (for example, 0,2 specifies a waveform showing channels 0 and 2). A channel range is a lower bound channel followed by a hyphen (-) or colon (:) followed by an upper bound channel (for example, 0-2 specifies a waveform showing channels 0, 1, and 2). You can include the same channel in multiple elements of this array. For example, if you choose 0:2 as the first element, 0, 2 as the second element, and 0 as the third element, the data parameter returns three waveforms: the first depicting channels 0 through 2, the second depicting channels 0 and 2, and the third depicting just channel 0. |
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timestamp type specifies whether the timestamp for the waveform data is relative or absolute. |
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starting record specifies the record at which you want to start fetching data. |
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error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
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instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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data returns the acquired data as an array of waveforms, one for each element in the channel list parameter. |
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number of samples read returns the number of samples that were successfully acquired and transferred into data. |
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error out contains error information. This output provides standard error out functionality.
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2D U32
This instance of niHSDIO Read Waveform returns the acquired waveform as a two-dimensional array of unsigned 32-bit integers.
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instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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|
samples to read specifies the number of samples to fetch. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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starting record specifies the record at which you want to start fetching data. |
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records to fetch specifies how many records you want to fetch from onboard memory. |
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error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
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instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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data returns the data for the waveform. |
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wfm info returns the absolute and relative timestamp for the operation, the dt, and the actual number of samples read.
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error out contains error information. This output provides standard error out functionality.
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2D U16
This instance of niHSDIO Read Waveform returns the acquired waveform as a two-dimensional array of unsigned 16-bit integers.
|
instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
||||||||||||
|
samples to read specifies the number of samples to fetch. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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starting record specifies the record at which you want to start fetching data. |
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records to fetch specifies how many records you want to fetch from onboard memory. |
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error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
|
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instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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 |
data returns the data for the waveform. |
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wfm info returns the absolute and relative timestamp for the operation, the dt, and the actual number of samples read.
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error out contains error information. This output provides standard error out functionality.
|
2D U8
This instance of niHSDIO Read Waveform returns the acquired waveform as a two-dimensional array of unsigned 8-bit integers.
|
instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
||||||||||||
|
samples to read specifies the number of samples to fetch. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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starting record specifies the record at which you want to start fetching data. |
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|
records to fetch specifies how many records you want to fetch from onboard memory. |
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error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
|
||||||||||||
|
instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
||||||||||||
 |
data returns the data for the waveform. |
||||||||||||
|
wfm info returns the absolute and relative timestamp for the operation, the dt, and the actual number of samples read.
|
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error out contains error information. This output provides standard error out functionality.
|
1D WDT
This instance of niHSDIO Read Waveform returns the acquired waveforms from the subset of channels listed in the channel list parameter as an array of waveform data type data. Each waveform only contains data from the subset of channels specified in the channel list parameter, not from all of the channels listed in the niHSDIO Assign Dynamic Channels VI, unless you leave the channel list parameter blank.
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instrument handle identifies your instrument session. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
||||||
|
samples to read specifies the number of samples to fetch. If you specify a value for samples to read that is greater than the number of samples in the device memory, NI-HSDIO returns the samples that are acquired after max time milliseconds. Setting this parameter to -1 acquires the samples per record specified in the niHSDIO Configure Acquisition Size VI. |
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|
max time milliseconds specifies, in milliseconds, the time allotted for the VI to complete before NI-HSDIO returns a timeout error. If you set the value to -1, the VI never times out. If you set this parameter to 0, the VI returns immediately with up to the number of samples specified in samples to read. If samples to read is greater than the number of samples in the device memory and all the available samples are acquired before a timeout, NI-HSDIO returns the available samples. |
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channel list specifies the channels from which to read waveform data. You must assign all channels that you want to read using the niHSDIO Assign Dynamic Channels VI before selecting those channels with this parameter. NI-HSDIO reads waveform data in the order that you list channels in this parameter, not in the order that those channels are listed in the niHSDIO Assign Dynamic Channels VI. If you leave this parameter blank, NI-HSDIO reads all channels that were set using the niHSDIO Assign Dynamic Channels VI. Specify multiple channels by using a channel list or a channel range. A channel list is a comma (,) separated sequence of channel names (for example, 0,2 specifies channels 0 and 2). A channel range is a lower bound channel followed by a hyphen (-) or colon (:) followed by an upper bound channel (for example, 0-2 specifies channels 0, 1, and 2). |
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timestamp type specifies whether the timestamp for the waveform data is relative or absolute. |
||||||
|
starting record specifies the record at which you want to start fetching data. |
||||||
|
records to fetch specifies how many records you want to fetch from onboard memory. |
||||||
|
error in (no error) describes error conditions that occur before this node runs. This input provides standard error in functionality.
|
||||||
|
instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niHSDIO Init Acquisition Session VI. |
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 |
data returns the data for the waveform. |
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actual samples read returns the number of samples read. |
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error out contains error information. This output provides standard error out functionality.
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