niScope Read (poly)

NI-SCOPE LabVIEW

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niScope Read (poly)

Initiates an acquisition, waits for it to complete, and acquires data.

Use the pull-down menu to select an instance of this VI.

Cluster

Initiates an acquisition, waits for it to complete, and retrieves the data for a single channel and record.

timeout is the time (in seconds) to wait for the data to be acquired; use 0 for this parameter to tell NI-SCOPE to fetch whatever is currently available.
instrument handle identifies a particular instrument session.
channel is the channel from which to acquire data. For more information, refer to Channel String Syntax.
numSamples is 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. Use –1 for this parameter if you want to fetch all available samples. The VI reads the actual record length and attempts to acquire all available samples. If it fails to complete within the timeout period, the VI returns an error.
error in describes error conditions that occur before this VI runs. The default input of this cluster is no error. If an error already occurred, this VI returns the value of error in in error out. The VI runs normally only if no incoming error exists. Otherwise, the VI passes the error in value to error out. The error in cluster contains the following parameters:
status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is a negative error code. If status is FALSE, code is 0 or a warning code.
source identifies where an error occurred. The source string includes the name of the VI that produced the error, what inputs are in error, and how to eliminate the error.
instrument handle out has the same value as the instrument handle.
wfm info contains all the timing and scaling information about the waveform.
actualSamples is the actual number of samples in the acquired waveform; this number may be less than numSamples if the number you request is not available.
absoluteInitialX is the timestamp in seconds of the first fetched sample that is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output.
relativeInitialX is the time in seconds from the trigger to the first sample in the fetched waveform.
xIncrement indicates the time in seconds between two samples in the acquired waveform.
gain is the gain factor of the given channel.

Use for scaling binary data with the following formula:

voltage = binary data × gain factor + offset
offset is the offset factor of the given channel.

Use for scaling binary data with the following formula:

voltage = binary data × gain factor + offset

waveform is a cluster containing the initial x value, xIincrement, and a waveform array. This output can be wired directly to the LabVIEW waveform graph, so the waveform is plotted with timing information. The initial x value in the cluster is relative to the trigger. The relative initial x value is the time from the trigger to the first point so the trigger always occurs at time equals zero.
relativeInitialX is the time in seconds from the trigger to the first sample in the fetched waveform.
xIncrement indicates the time in seconds between two samples in the acquired waveform.
wfm is an array of waveform data containing one waveform without any timing information.
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, it describes the error status that this VI or function produces.
status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source identifies where and why an error occurred. The source string includes the name of the VI that produced the error, what inputs are in error, and how to eliminate the error.

WDT

Returns the waveform the digitizer acquires for the specified channel. The VI initiates an acquisition that returns a scaled voltage waveform in a waveform data type that includes timing information.

timestamp type specifies the time basis for the timestamp on the WDT data.

Defined Values

absolute

relative
timeout is the time (in seconds) to wait for the data to be acquired; use 0 for this parameter to tell NI-SCOPE to fetch whatever is currently available.
instrument handle identifies a particular instrument session.
channel is the channel from which to acquire data. For more information, refer to Channel String Syntax.
numSamples is 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. Use –1 for this parameter if you want to fetch all available samples. The VI reads the actual record length and attempts to acquire all available samples. If it fails to complete within the timeout period, the VI returns an error.
error in describes error conditions that occur before this VI runs. The default input of this cluster is no error. If an error already occurred, this VI returns the value of error in in error out. The VI runs normally only if no incoming error exists. Otherwise, the VI passes the error in value to error out. The error in cluster contains the following parameters:
status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is a negative error code. If status is FALSE, code is 0 or a warning code.
source identifies where an error occurred. The source string includes the name of the VI that produced the error, what inputs are in error, and how to eliminate the error.
instrument handle out has the same value as the instrument handle.
wfm info contains all the timing and scaling information about the waveform.
actualSamples is the actual number of samples in the acquired waveform; this number may be less than numSamples if the number you request is not available.
absoluteInitialX is the timestamp in seconds of the first fetched sample that is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output.
relativeInitialX is the time in seconds from the trigger to the first sample in the fetched waveform.
xIncrement indicates the time in seconds between two samples in the acquired waveform.
gain is the gain factor of the given channel.

Use for scaling binary data with the following formula:

voltage = binary data × gain factor + offset
offset is the offset factor of the given channel.

Use for scaling binary data with the following formula:

voltage = binary data × gain factor + offset

wfm returns data for wiring to a graph, including the timing information.
t0 is the time corresponding to the first data value in the waveform.
dt is the time interval, or duration, between data points in the waveform.
Y contains the data values of a waveform.
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, it describes the error status that this VI or function produces.
status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source identifies where and why an error occurred. The source string includes the name of the VI that produced the error, what inputs are in error, and how to eliminate the error.

1D Cluster

Initiates an acquisition, waits for it to complete, and retrieves the data for multiple channels and records.

timeout is the time (in seconds) to wait for the data to be acquired; use 0 for this parameter to tell NI-SCOPE to fetch whatever is currently available.
instrument handle identifies a particular instrument session.
channelList is the channel from which to acquire data. For more information, refer to Channel String Syntax.

Default Value: 0
numSamples is 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. Use –1 for this parameter if you want to fetch all available samples. The VI reads the actual record length and attempts to acquire all available samples. If it fails to complete within the timeout period, the VI returns an error.
error in describes error conditions that occur before this VI runs. The default input of this cluster is no error. If an error already occurred, this VI returns the value of error in in error out. The VI runs normally only if no incoming error exists. Otherwise, the VI passes the error in value to error out. The error in cluster contains the following parameters:
status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is a negative error code. If status is FALSE, code is 0 or a warning code.
source identifies where an error occurred. The source string includes the name of the VI that produced the error, what inputs are in error, and how to eliminate the error.
instrument handle out has the same value as the instrument handle.
wfm info contains all the timing and scaling information about the waveform.
actualSamples is the actual number of samples in the acquired waveform; this number may be less than numSamples if the number you request is not available.
absoluteInitialX is the timestamp in seconds of the first fetched sample that is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output.
relativeInitialX is the time in seconds from the trigger to the first sample in the fetched waveform.
xIncrement indicates the time in seconds between two samples in the acquired waveform.
gain is the gain factor of the given channel.

Use for scaling binary data with the following formula:

voltage = binary data × gain factor + offset
offset is the offset factor of the given channel.

Use for scaling binary data with the following formula:

voltage = binary data × gain factor + offset

waveform is an array of clusters, each containing the initial x value, x increment, and a waveform array. This output can be wired directly to the LabVIEW waveform graph, so each waveform in the array is plotted with timing information. The initial x value in the cluster is the value relative to the trigger. The relative initial x value is the time from the trigger to the first point so the trigger always occurs at time equals zero.

The array of clusters includes waveforms from multiple channels, records, and acquisition types. For example, if the acquisition type is normal there is one waveform per channel per record. If you call the fetch function during a normal acquisition with the channel string "0,1" the order of the output is:

record 0, channel 0
record 0, channel 1
record 1, channel 0
record 1, channel 1

initial X contains the time (in seconds) of the first point in the waveform with respect to the trigger.
xIncrement indicates the time in seconds between two samples in the acquired waveform.
waveform contains the voltage data (the y-axis data in the graph).
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, it describes the error status that this VI or function produces.
status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source identifies where and why an error occurred. The source string includes the name of the VI that produced the error, what inputs are in error, and how to eliminate the error.

1D WDT

Initiates an acquisition and returns a one-dimensional array of LabVIEW waveform data types that includes timing information. This VI is only supported in LabVIEW 7.0 or later.

timestamp type specifies the time basis for the timestamp on the WDT data.

Defined Values

absolute

relative
timeout is the time (in seconds) to wait for the data to be acquired; use 0 for this parameter to tell NI-SCOPE to fetch whatever is currently available.
instrument handle identifies a particular instrument session.
channelList is the channel from which to acquire data. For more information, refer to Channel String Syntax.

Default Value: 0
numSamples is 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. Use –1 for this parameter if you want to fetch all available samples. The VI reads the actual record length and attempts to acquire all available samples. If it fails to complete within the timeout period, the VI returns an error.
error in describes error conditions that occur before this VI runs. The default input of this cluster is no error. If an error already occurred, this VI returns the value of error in in error out. The VI runs normally only if no incoming error exists. Otherwise, the VI passes the error in value to error out. The error in cluster contains the following parameters:
status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is a negative error code. If status is FALSE, code is 0 or a warning code.
source identifies where an error occurred. The source string includes the name of the VI that produced the error, what inputs are in error, and how to eliminate the error.
instrument handle out has the same value as the instrument handle.
wfm info contains all the timing and scaling information about the waveform.
actualSamples is the actual number of samples in the acquired waveform; this number may be less than numSamples if the number you request is not available.
absoluteInitialX is the timestamp in seconds of the first fetched sample that is comparable between records and acquisitions; devices that do not support this parameter use 0 for this output.
relativeInitialX is the time in seconds from the trigger to the first sample in the fetched waveform.
xIncrement indicates the time in seconds between two samples in the acquired waveform.
gain is the gain factor of the given channel.

Use for scaling binary data with the following formula:

voltage = binary data × gain factor + offset
offset is the offset factor of the given channel.

Use for scaling binary data with the following formula:

voltage = binary data × gain factor + offset

wfm returns a one-dimensional array of LabVIEW waveform data types that contain timing information. If you specify a channel list, NI-SCOPE returns the waveforms in the list order. NI-SCOPE returns these records sequentially, so all record 0 waveforms are first.

For example, with a two-channel list, you would have the following index values:

index 0 = record 0, channel 0

index 1 = record 0, channel 1

index 2 = record 1, channel 0

index 3 = record 1, channel 1

t0 is the time corresponding to the first data value in the waveform.
dt is the time interval, or duration, between data points in the waveform.
Y contains the data values of a waveform.
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, it describes the error status that this VI or function produces.
status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
source identifies where and why an error occurred. The source string includes the name of the VI that produced the error, what inputs are in error, and how to eliminate the error.
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