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Read Data (NChan Double) (G Dataflow)

Last Modified: August 30, 2019

Returns double-precision, floating-point number data from the channels specified in channel names in.

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count

Maximum number of data elements to read for each channel.

If you use the default value, this node reads all available elements.

Default: -1

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offset

Number of data elements into the TDMS file at which this node begins to read.

Default: 0

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tdm file in

TDMS file reference on the server.

Use Query TDMS Files to obtain the reference.

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group name in

Channel group to analyze.

If you do not wire group name in, this node reads the channel name from the next group in the TMDS file each time it executes.

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channel names in

Channels to read data from.

If you do not wire channel name in, this node reads all channels in the group.

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return channels in file order?

Boolean specifying whether the node returns data channels in the same order as they exist in the TDMS file.

True Return data channels in the same order as they exist in the TDMS file.
False Return data channels in the same order as you specify in channel names in.

Default: False

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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

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tdm file out

TDMS file reference on the server.

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group name out

Channel group returned from the TDMS file.

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channel names out

Names of the channels associated with the group you specified.

The order of the names returned correspond to the order of the data array when return channels in file order? is True.

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data

2D array of double-precision, floating-point number data read from the TDMS file.

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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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end of channel data?

A Boolean that indicates whether the node read the last of the data for any channel in channel names out.

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end of groups?

Boolean that indicates whether the node read data from the last group in the TDMS file.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Supported in VIs that run in a web application


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