niFgen_CreateWaveformFromFileHWS
ViStatus niFgen_CreateWaveformFromFileHWS (ViSession vi, ViConstString channelName, ViConstString filename, ViBoolean useRateFromWaveform, ViBoolean useGain&OffsetFromWaveform, ViInt32* waveformHandle);
Purpose
Takes the waveform data from the specified HWS (Hierarchical Waveform Storage) file and creates an onboard waveform for use in Arbitrary Waveform or Arbitrary Sequence output mode. The waveformHandle returned by the function can be used later for setting the active waveform, changing the data in the waveform, building sequences of waveforms, or deleting the waveform when it is no longer needed.
When the Analog Waveform Editor saves data in an HWS file, it also stores the rate, gain and offset with the data. If the useRateFromWaveform and useGain&OffsetFromWaveform inputs are set to VI_TRUE, this function also sets those properties on NI-FGEN.
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Notes If you choose to have this function set the gain and offset properties for you, you should not use the niFgen_ConfigureArbWaveform or niFgen_ConfigureArbSequence functions, as they also set the gain and offset, thereby overriding the values set by this function. Instead, use the NIFGEN_ATTR_ARB_WAVEFORM_HANDLE or NIFGEN_ATTR_ARB_SEQUENCE_HANDLE attributes. |
| HWS files may contain I16 or DBL data (depending on how it was saved). This function automatically adapts to either data type. If the file contains DBL data, it must be between -1.0 and +1.0. Check the "Scale Data to +/- 1V" option in the Analog Waveform Editor to ensure your data is between -1.0 and +1.0. |
Parameters
| Input | ||||||
| Name | Type | Description | ||||
| vi | ViSession | Identifies your instrument session. vi is obtained from the niFgen_init or the niFgen_InitWithOptions functions and identifies a particular instrument session. | ||||
| channelName | ViConstString | Specifies the channel name for which you want to create the waveform.
Defined Value: "0" Default Value: "0" |
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| fileName | ViConstString | The full path and name of the file where the waveform data resides. |
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| useRateFromWaveform | ViBoolean | If you set this parameter input to VI_TRUE and if onboard signal processing (OSP) is enabled, the 'rate' from the waveform is interpreted as the data rate, and FGEN sets the data rate attribute for you. In all other cases, it is interpreted as the sample rate, and FGEN sets the sample rate attribute for you.
Defined Values
Default Value: VI_TRUE |
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| useGain&OffsetFromWaveform | ViBoolean | If this input is set to VI_TRUE, NI-FGEN retrieves the gain and offset values from the specified HWS file and applies them to the NI-FGEN driver.
Defined Values
Default Value: VI_TRUE |
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| Output | ||||||
| Name | Type | Description | ||||
| waveformHandle | ViInt32* | The handle that identifies the new waveform. This handle is used later when referring to this waveform. |
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Return Value
| Name | Type | Description | ||||||||
| Status | ViStatus | Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. You can examine the status code from each call to an NI-FGEN function to determine if an error occurred.
To obtain a text description of the status code, call the niFgen_error_message function. To obtain additional information about the error condition, call the niFgen_GetError function. To clear the error information from NI-FGEN, call the niFgen_ClearError function. The general meaning of the status code is as follows:
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