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IviScope Read Min Max Waveform [MmW] (G Dataflow)

Last Modified: October 24, 2017

Initiates new waveform acquisition and returns minimum and maximum waveforms from a specific channel. This function is used when the Acquisition Type is Peak Detect or Envelope.

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actual points

Value that indicates the number of points the node places in the Min Waveform Array and Max Waveform Array parameters.

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x increment

Value that indicates the length of time between points in the Min and Max Waveform Arrays. Units: seconds

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max waveform array

Returns the maximum waveform that the oscilloscope acquires. Units: volts

Associated Nodes

IviScope Actual Record Length Returns the number of points the oscilloscope acquires for each channel.
IviScope Configure Interpolation [I] Configures the interpolation method the oscilloscope uses.
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Note  

If you disable interpolation, the oscilloscope does not interpolate points in the waveform. If the oscilloscope cannot sample a value for a point in the waveform, the driver sets the corresponding element in the Waveform Array to an IEEE defined NaN (Not a Number) value and the VI returns IVISCOPE_WARN_INVALID_WFM_ELEMENT (0x3FFA2001).

IviScope Is Invalid Waveform Element Tests a waveform value for an invalid value condition.
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min waveform array

Returns the minimum waveform that the oscilloscope acquires. Units: volts

Associated Nodes

IviScope Actual Record Length Returns the number of points the oscilloscope acquires for each channel.
IviScope Configure Interpolation [I] Configures the interpolation method the oscilloscope uses.
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Note  

If you disable interpolation, the oscilloscope does not interpolate points in the waveform. If the oscilloscope cannot sample a value for a point in the waveform, the driver sets the corresponding element in the Waveform Array to an IEEE defined NaN (Not a Number) value and the VI returns IVISCOPE_WARN_INVALID_WFM_ELEMENT (0x3FFA2001).

IviScope Is Invalid Waveform Element Tests a waveform value for an invalid value condition.
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maximum time

Value indicating the maximum length of time in which to allow the read waveform operation to complete. Units: milliseconds.

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Note  

The Maximum Time parameter applies only to this node. It has no effect on other timeout parameters or properties.

IVISCOPE_ERROR_MAX_TIME_EXCEEDED Error

Defined Values

IVISCOPE_VAL_MAX_TIME_INFINITE (-1)
IVISCOPE_VAL_MAX_TIME_IMMEDIATE (0)

Default: 5000 (ms)

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waveform size

Value representing the expected size of the waveforms that the oscilloscope acquires. That value is greater than or equal to the minimum number of points you specify in the IviScope Configure Acquisition Record Node.

Determining Waveform Size

Default: 1000

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channel name

String you pass to represent the virtual channel name that you assign to the instrument in the Configuration Utility from which you want to read the minimum and maximum waveforms. This control accepts virtual channel names you have assigned to the specific instrument you are using. It also accepts the instrument-specific channel names.

Achieving Interchangeability

Virtual Channel Names

The virtual channel name should be sufficiently specific to the test system such that it is unlikely to conflict with a physical channel name. Virtual channel names are aliases for instrument-specific channel strings. The instrument-specific channel strings can differ from one instrument to another. Virtual channel names allow you to use and swap instruments without having to change the channel names in your source code. You assign a virtual channel name to an instrument-specific channel through the Configuration Utility.

Default: "CHANNEL1"

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instrument handle out

The instrument handle that you obtain from the IviScope Initialize or IviScope Initialize With Options node. The handle identifies a particular instrument session.

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instrument handle

The instrument handle that you obtain from the IviScope Initialize or IviScope Initialize With Options node. The handle identifies a particular instrument session.

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error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.
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error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

Channel Not Enabled Error

If the channel is not enabled for the acquisition, this function returns the Channel Not Enabled error.

Invalid Acquisition Type Error

If the acquisition type is not one of the listed types, the function returns the Invalid Acquisition Type error.

Max Time Exceeded Error

If the oscilloscope did not complete the acquisition within the time period the user specified with the MaxTimeMilliseconds parameter, the function returns the Max Time Exceeded error.

Obtaining Min/Max Waveforms

This function initiates an acquisition on the enabled channels. It then waits for the acquisition to complete, and returns the min/max waveforms for the specified channel. Call the Fetch Min Max Waveform function to obtain the min/max waveforms for each of the remaining enabled channels without initiating another acquisition.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application


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