Table Of Contents

Multi Read History (G Dataflow)

Last Modified: November 18, 2019

Returns the historical values from multiple tags in a single operation.

connector_pane_image
datatype_icon

tags in

Reference to a specific tag or a group of tags on SystemLink Server or SystemLink Cloud.

Use Open Tag or Query Tags to obtain this reference.

datatype_icon

window

Time range you specify to read historical tag values.

The default is set to read all values decimated to 1,000.

datatype_icon

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

datatype_icon

next window

Next page of historical tag data, if available.

datatype_icon

tags out

Reference to a specific tag or a group of tags on SystemLink Server or SystemLink Cloud.

Use Open Tag or Query Tags to obtain this reference.

datatype_icon

values

Data values of the tag history.

datatype_icon

end of data?

Boolean that indicates whether the node read the last of the data for the tag.

datatype_icon

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.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

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


Recently Viewed Topics