You are here: NI Home > Support > Product Reference > Manuals > LabVIEW 8.6 Datalogging and Supervisory Control Module Help

Owning Palette: Historical VIs

Installed With: DSC Module

Retrieves a list of trace names from a Citadel database based on a particular pattern.

	timeout limits the time that the VI waits for data to be returned from the database. The default is 30 seconds. A timeout value of less than or equal to 0 indicates no timeout, which means that the VI waits indefinitely until the data is returned.
	database URL is the computer name and the database name where the Citadel database resides. Enter the database URL in the format \\computer\database_name. For example, if you have a copy of the LabVIEW Datalogging and Supervisory Control (DSC) Module and Citadel service installed on a computer named datalogger and the name of the database on that computer is data, you can access the data on datalogger from another computer by using the path \\datalogger\data. If you provide a database name only, the DSC Module searches for the database on the local computer. If you do not wire database URL, the VI reads data from the database associated with the default DSC Module process.
	trace names specifies the traces. You can specify either Shared Variable references or existing traces for this parameter.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. 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 nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	get time range? retrieves a time range for trace list if get time range? is set to TRUE (default). If get time range? is FALSE, this VI does not return the first and last timestamps for the list of traces, which significantly increases the speed of the query when querying large databases.
	use * as wildcard signals the VI to interpret the asterisk character as a wildcard character in any trace name given if use * as wildcard is TRUE. The wildcard matches any set of zero or more characters.
	last timestamp is the date and time associated with the last data point retrieved from the historical database.
	database URL out returns the computer name and the database name to specify where the Citadel database resides. The format is \\computer\database_name.
	trace list is the list of traces that have historical data logged.
	first timestamp is the date and time associated with the first data point retrieved from the historical database.
	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. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. 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 describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.