NI SCOPE Acquisition Functions - ni/grpc-device GitHub Wiki
- niScope_Abort
- niScope_AcquisitionStatus
- niScope_Commit
- niScope_Fetch
- niScope_FetchComplex
- niScope_FetchComplexBinary16
- niScope_FetchBinary8
- niScope_FetchBinary16
- niScope_FetchBinary32
- niScope_GetNormalizationCoefficients
- niScope_GetScalingCoefficients
- niScope_InitiateAcquisition
- niScope_Read
ViStatus niScope_Abort (ViSession vi);
Aborts an acquisition and returns the digitizer to the Idle state. Call this function if the digitizer times out waiting for a trigger.
- NI-SCOPE Programming Flow
- Acquisition Functions
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_AcquisitionStatus (ViSession vi, ViInt32* status);
Returns status information about the acquisition to the status output parameter.
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| Output | ||
| Name | Type | Description |
| status | ViInt32* |
Returns whether the acquisition is complete, in progress, or unknown. Defined Values NISCOPE_VAL_ACQ_COMPLETE NISCOPE_VAL_ACQ_IN_PROGRESS NISCOPE_VAL_ACQ_STATUS_UNKNOWN |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_Commit (ViSession vi);
Commits to hardware all the parameter settings associated with the task. Use this function if you want a parameter change to be immediately reflected in the hardware.
- SMC-Based Digitizers Acquisition Engine State Diagram
- NI-SCOPE Programming Flow
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_Fetch (ViSession vi, ViConstString channelList, ViReal64 timeout, ViInt32 numSamples, ViReal64* wfm, struct niScope_wfmInfo* wfmInfo;
Returns the waveform from a previously initiated acquisition that the digitizer acquires for the specified channel. This function returns scaled voltage waveforms.
This function may return multiple waveforms depending on the number of channels, the acquisition type, and the number of records you specify.
 |
Notes You can use niScope_Read instead of this function. niScope_Read starts an acquisition on all enabled channels, waits for the acquisition to complete, and returns the waveform for the specified channel. Some functionality, such as time stamping, is not supported in all digitizers. Refer to Features Supported by Device for more information. |
|---|
- Fetching Data
- Acquiring Data Continuously
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channelList | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| timeout | ViReal64 | The time to wait in seconds for data to be acquired; using 0 for this parameter tells NI-SCOPE to fetch whatever is currently available. Using -1 for this parameter implies infinite timeout. |
| numSamples | ViInt32 | The maximum number of samples to fetch for each waveform. If the acquisition finishes with fewer points than requested, some devices return partial data if the acquisition finished, was aborted, or a timeout of 0 was used. If it fails to complete within the timeout period, the function returns an error. |
| Output | ||
| Name | Type | Description |
| wfm | ViReal64* |
Returns an array whose length is the numSamples times number of waveforms. Call niScope_ActualNumWfms to determine the number of waveforms. NI-SCOPE returns this data sequentially, so all record 0 waveforms are first. For example, with a channel list of 0,1, you would have the following index values: index 0 = record 0, channel 0 index x = record 0, channel 1 index 2x = record 1, channel 0 index 3x = record 1, channel 1 Where x = the record length |
| wfmInfo | struct niScope_ wfmInfo* |
Returns an array of structures with the following timing and scaling information about each waveform: - relativeInitialX—the time (in seconds) from the trigger to the first sample in the fetched waveform - absoluteInitialX—timestamp (in seconds) of the first fetched sample. This timestamp is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output. - xIncrement—the time between points in the acquired waveform in seconds - actualSamples—the actual number of samples fetched and placed in the waveform array - gain—the gain factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset - offset—the offset factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset Call niScope_ActualNumWfms to determine the size of this array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
niScope_FetchComplex ( ViSession vi, ViConstString channelList, ViReal64 timeout, ViInt32 numSamples, NIComplexNumber* wfm, struct niScope_wfmInfo* wfmInfo;
Retrieves data that the digitizer has acquired from a previously initiated acquisition and returns a one-dimensional array of complex, scaled waveforms.
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channelList | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| timeout | ViReal64 | The time to wait in seconds for data to be acquired; using 0 for this parameter tells NI-SCOPE to fetch whatever is currently available. Using -1 for this parameter implies infinite timeout. |
| numSamples | ViInt32 | The maximum number of samples to fetch for each waveform. If the acquisition finishes with fewer points than requested, some devices return partial data if the acquisition finished, was aborted, or a timeout of 0 was used. If it fails to complete within the timeout period, the function returns an error. |
| Output | ||
| Name | Type | Description |
| wfm | NIComplexNumber* | Returns an array whose length is the numSamples times number of waveforms. Call niScope_ActualNumWfms to determine the number of waveforms. |
| wfmInfo | struct niScope_ wfmInfo* |
Returns an array of structures with the following timing and scaling information about each waveform: - relativeInitialX—the time (in seconds) from the trigger to the first sample in the fetched waveform - absoluteInitialX—timestamp (in seconds) of the first fetched sample. This timestamp is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output. - xIncrement—the time between points in the acquired waveform in seconds - actualSamples—the actual number of samples fetched and placed in the waveform array - gain—the gain factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset - offset—the offset factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset Call niScope_ActualNumWfms to determine the size of this array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
niScope_FetchComplexBinary16 ( ViSession vi, ViConstString channelList, ViReal64 timeout, ViInt32 numSamples, NIComplexI16* wfm, Struct niScope_wfmInfo* wfmInfo;
Retrieves data from single channels and records. Returns a one-dimensional array of complex binary 16-bit waveforms.
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channelList | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| timeout | ViReal64 | The time to wait in seconds for data to be acquired; using 0 for this parameter tells NI-SCOPE to fetch whatever is currently available. Using -1 for this parameter implies infinite timeout. |
| numSamples | ViInt32 | The maximum number of samples to fetch for each waveform. If the acquisition finishes with fewer points than requested, some devices return partial data if the acquisition finished, was aborted, or a timeout of 0 was used. If it fails to complete within the timeout period, the function returns an error. |
| Output | ||
| Name | Type | Description |
| wfm | NIComplexI16* | Returns an array whose length is the numSamples times number of waveforms. Call niScope_ActualNumWfms to determine the number of waveforms. |
| wfmInfo | struct niScope_ wfmInfo* |
Returns an array of structures with the following timing and scaling information about each waveform: - relativeInitialX—the time (in seconds) from the trigger to the first sample in the fetched waveform - absoluteInitialX—timestamp (in seconds) of the first fetched sample. This timestamp is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output. - xIncrement—the time between points in the acquired waveform in seconds - actualSamples—the actual number of samples fetched and placed in the waveform array - gain—the gain factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset - offset—the offset factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset Call niScope_ActualNumWfms to determine the size of this array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_FetchBinary8 (ViSession vi, ViConstString channelList, ViReal64 timeout, ViInt32 numSamples, ViInt8* wfm, struct niScope_wfmInfo* wfmInfo;
Retrieves data from a previously initiated acquisition and returns binary 8-bit waveforms. This function may return multiple waveforms depending on the number of channels, the acquisition type, and the number of records you specify.
Refer to Using Fetch Functions for more information on using this function.
|
Note Some functionality, such as time stamping, is not supported in all digitizers. Refer to Features Supported by Device) for more information. |
|---|
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channelList | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| timeout | ViReal64 | The time to wait in seconds for data to be acquired; using 0 for this parameter tells NI-SCOPE to fetch whatever is currently available. Using -1 for this parameter implies infinite timeout. |
| numSamples | ViInt32 | The maximum number of samples to fetch for each waveform. If the acquisition finishes with fewer points than requested, some devices return partial data if the acquisition finished, was aborted, or a timeout of 0 was used. If it fails to complete within the timeout period, the function returns an error. |
| Output | ||
| Name | Type | Description |
| wfm | ViInt8* |
Returns an array whose length is the numSamples times number of waveforms. Call niScope_ActualNumWfms to determine the number of waveforms. NI-SCOPE returns this data sequentially, so all record 0 waveforms are first. For example, with a channel list of 0,1, you would have the following index values: index 0 = record 0, channel 0 index x = record 0, channel 1 index 2x = record 1, channel 0 index 3x = record 1, channel 1 Where x = the record length |
| wfmInfo | struct niScope_ wfmInfo* |
Returns an array of structures with the following timing and scaling information about each waveform: - relativeInitialX—the time (in seconds) from the trigger to the first sample in the fetched waveform - absoluteInitialX—timestamp (in seconds) of the first fetched sample. This timestamp is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output. - xIncrement—the time between points in the acquired waveform in seconds - actualSamples—the actual number of samples fetched and placed in the waveform array - gain—the gain factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset - offset—the offset factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset Call niScope_ActualNumWfms to determine the size of this array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_FetchBinary16 (ViSession vi, ViConstString channelList, ViReal64 timeout, ViInt32 numSamples, ViInt16* wfm, struct niScope_wfmInfo* wfmInfo;
Retrieves data from a previously initiated acquisition and returns binary 16-bit waveforms. This function may return multiple waveforms depending on the number of channels, the acquisition type, and the number of records you specify.
Refer to Using Fetch Functions for more information on using this function.
|
Note Some functionality, such as time stamping, is not supported in all digitizers. Refer to Features Supported by Device) for more information. |
|---|
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channelList | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| timeout | ViReal64 | The time to wait in seconds for data to be acquired; using 0 for this parameter tells NI-SCOPE to fetch whatever is currently available. Using -1 for this parameter implies infinite timeout. |
| numSamples | ViInt32 | The maximum number of samples to fetch for each waveform. If the acquisition finishes with fewer points than requested, some devices return partial data if the acquisition finished, was aborted, or a timeout of 0 was used. If it fails to complete within the timeout period, the function returns an error. |
| Output | ||
| Name | Type | Description |
| wfm | ViInt16* |
Returns an array whose length is the numSamples times number of waveforms. Call niScope_ActualNumWfms to determine the number of waveforms. NI-SCOPE returns this data sequentially, so all record 0 waveforms are first. For example, with a channel list of 0,1, you would have the following index values: index 0 = record 0, channel 0 index x = record 0, channel 1 index 2x = record 1, channel 0 index 3x = record 1, channel 1 Where x = the record length |
| wfmInfo | struct niScope_ wfmInfo* |
Returns an array of structures with the following timing and scaling information about each waveform: - relativeInitialX—the time (in seconds) from the trigger to the first sample in the fetched waveform - absoluteInitialX—timestamp (in seconds) of the first fetched sample. This timestamp is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output. - xIncrement—the time between points in the acquired waveform in seconds - actualSamples—the actual number of samples fetched and placed in the waveform array - gain—the gain factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset - offset—the offset factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset Call niScope_ActualNumWfms to determine the size of this array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_FetchBinary32 (ViSession vi, ViConstString channelList, ViReal64 timeout, ViInt32 numSamples, ViInt32* wfm, struct niScope_wfmInfo* wfmInfo;
Retrieves data from a previously initiated acquisition and returns binary 32-bit waveforms. This function may return multiple waveforms depending on the number of channels, the acquisition type, and the number of records you specify.
Refer to Using Fetch Functions for more information on using this function.
|
Note Some functionality, such as time stamping, is not supported in all digitizers. Refer to Features Supported by Device) for more information. |
|---|
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channelList | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| timeout | ViReal64 | The time to wait in seconds for data to be acquired; using 0 for this parameter tells NI-SCOPE to fetch whatever is currently available. Using -1 for this parameter implies infinite timeout. |
| numSamples | ViInt32 | The maximum number of samples to fetch for each waveform. If the acquisition finishes with fewer points than requested, some devices return partial data if the acquisition finished, was aborted, or a timeout of 0 was used. If it fails to complete within the timeout period, the function returns an error. |
| Output | ||
| Name | Type | Description |
| wfm | ViInt32* |
Returns an array whose length is the numSamples times number of waveforms. Call niScope_ActualNumWfms to determine the number of waveforms. NI-SCOPE returns this data sequentially, so all record 0 waveforms are first. For example, with a channel list of 0,1, you would have the following index values: index 0 = record 0, channel 0 index x = record 0, channel 1 index 2x = record 1, channel 0 index 3x = record 1, channel 1 Where x = the record length |
| wfmInfo | struct niScope_ wfmInfo* |
Returns an array of structures with the following timing and scaling information about each waveform: - relativeInitialX—the time (in seconds) from the trigger to the first sample in the fetched waveform - absoluteInitialX—timestamp (in seconds) of the first fetched sample. This timestamp is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output. - xIncrement—the time between points in the acquired waveform in seconds - actualSamples—the actual number of samples fetched and placed in the waveform array - gain—the gain factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset - offset—the offset factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset Call niScope_ActualNumWfms to determine the size of this array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus _VI_FUNC niScope_GetNormalizationCoefficients (ViSession vi, ViConstString channelList, ViInt32 bufferSize, struct niScope_coefficientInfo coefficientInfo[], ViInt32* numberOfCoefficientSets;
Returns coefficients that can be used to convert binary data to normalized and calibrated data.
Refer to Scaling and Normalization of Binary Data for more information about how to use this function.
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channel List | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| bufferSize | ViInt32 |
The array size for the coefficentInfo parameter. To determine the size of the buffer to allocate for coefficientInfo, pass a value of 0 to the buffersize parameter and a value of NULL to the coefficientInfo parameter. In this case, the return value of the numberOfCoefficientSets parameter is the size of the array necessary to hold the coefficient structures. Allocate an array of niScope_coefficientInfo structures of this size, then call this function again (with the correct bufferSize parameter) to retrieve the actual values. |
| coefficientInfo | struct niScope_coefficientInfo | An array of structures containing gain and offset coefficients for a given channel. |
| Output | ||
| Name | Type | Description |
| numberOfCoefficientSets | ViInt32* | Returns the number of coefficient sets returned in the coefficientInfo array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus _VI_FUNC niScope_GetScalingCoefficients (ViSession vi, ViConstString channelList, ViInt32 bufferSize, struct niScope_coefficientInfo coefficientInfo[], ViInt32* numberOfCoefficientSets;
Returns coefficients that can be used to scale binary data to volts.
Refer to Scaling and Normalization of Binary Data for more information about how to use this function.
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channelList | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| bufferSize | ViInt32 |
The array size for the coefficentInfo parameter. To determine the size of the buffer to allocate for coefficientInfo, pass a value of 0 to the buffersize parameter and a value of NULL to the coefficientInfo parameter. In this case, the return value of the numberOfCoefficientSets parameter is the size of the array necessary to hold the coefficient structures. Allocate an array of niScope_coefficientInfo structures of this size, then call this function again (with the correct bufferSize parameter) to retrieve the actual values. |
| coefficientInfo | struct niScope_coefficientInfo | An array of structures containing gain and offset coefficients for a given channel. |
| Output | ||
| Name | Type | Description |
| numberOfCoefficientSets | ViInt32 | Returns the number of coefficient sets returned in the coefficientInfo array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_InitiateAcquisition (ViSession vi);
Initiates a waveform acquisition.
After calling this function, the digitizer leaves the Idle state and waits for a trigger. The digitizer acquires a waveform for each channel you enable with niScope_ConfigureVertical.
- SMC-Based Digitizers Acquisition Engine State Diagram
- NI-SCOPE Programming Flow
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |
ViStatus niScope_Read (ViSession vi, ViConstString channelList, ViReal64 timeout, ViInt32 numSamples, ViReal64* wfm, struct niScope_wfmInfo* wfmInfo;
Initiates an acquisition, waits for it to complete, and retrieves the data. The process is similar to calling niScope_InitiateAcquisition, niScope_AcquisitionStatus, and niScope_Fetch. The only difference is that with niScope_Read, you enable all channels specified with channelList before the acquisition; in the other method, you enable the channels with niScope_ConfigureVertical.
This function may return multiple waveforms depending on the number of channels, the acquisition type, and the number of records you specify.
|
Note Some functionality is not supported in all digitizers. Refer to Features Supported by Device) for more information. |
|---|
- Acquisition Functions
- NI-SCOPE Programming Flow
| Input | ||
|---|---|---|
| Name | Type | Description |
| vi | ViSession | The instrument handle you obtain from niScope_init that identifies a particular instrument session. |
| channelList | ViConstString | The channel to configure. For more information, refer to Channel String Syntax. |
| timeout | ViReal64 | The time to wait in seconds for data to be acquired; using 0 for this parameter tells NI-SCOPE to fetch whatever is currently available. Using -1 for this parameter implies infinite timeout. |
| numSamples | ViInt32 | The maximum number of samples to fetch for each waveform. If the acquisition finishes with fewer points than requested, some devices return partial data if the acquisition finished, was aborted, or a timeout of 0 was used. If it fails to complete within the timeout period, the function returns an error. |
| Output | ||
| Name | Type | Description |
| wfm | ViReal64* |
Returns an array whose length is the numSamples times number of waveforms. Call niScope_ActualNumWfms to determine the number of waveforms. NI-SCOPE returns this data sequentially, so all record 0 waveforms are first. For example, with a channel list of 0,1, you would have the following index values: index 0 = record 0, channel 0 index x = record 0, channel 1 index 2x = record 1, channel 0 index 3x = record 1, channel 1 Where x = the record length |
| wfmInfo | struct niScope_ wfmInfo* |
Returns an array of structures with the following timing and scaling information about each waveform: - relativeInitialX—the time (in seconds) from the trigger to the first sample in the fetched waveform - absoluteInitialX—timestamp (in seconds) of the first fetched sample. This timestamp is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output. - xIncrement—the time between points in the acquired waveform in seconds - actualSamples—the actual number of samples fetched and placed in the waveform array - gain—the gain factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset - offset—the offset factor of the given channel; useful for scaling binary data with the following formula: voltage = binary data × gain factor + offset Call niScope_ActualNumWfms to determine the size of this array. |
| Name | Type | Description |
|---|---|---|
| Status | ViStatus | Reports the status of this operation. To obtain a text description of the status code, call niScope_GetErrorMessage. To obtain additional information concerning the error condition, use niScope_GetError and niScope_ClearError. The general meaning of the status code is as follows: |
| Value | Meaning |
|---|---|
| 0 | Success |
| Positive Values | Warnings |
| Negative Values | Errors |