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Read Traces (DSC Module)

Reads the historical data for a group of shared variables using the specified time interval, up to the max points per trace specified.

You must manually select the polymorphic instance to use. If you do not wire database URL, this VI reads data from the database associated with the default DSC Module process.

If you do not wire time interval, the VI returns all historical data for the shared variables, up to the max points per trace specified. If you do not wire max points per trace, the VI returns all points between the start and stop timestamps set in time interval. If you do not wire interpolate data, the DSC Module preserves gaps in the data as invalid (NaN) values. If you set interpolate data to TRUE, the DSC Module ignores the gaps, and the trace interpolates across the gap in the data.

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

Read Traces (Numeric)

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.
max points per trace is the maximum number of points to read from the database. The default is –1. If max points per trace is less than zero, the VI returns all points available between start timestamp and stop timestamp. Otherwise, the number of points in the trace is the minimum of the actual number of data points between start timestamp and stop timestamp and max points in trace (all).
database URL is the computer name where the Citadel database resides and the name of the database. Enter the database URL in the format \\computer\database_name. If you do not wire database URL, the VI reads data from the database associated with the default DSC Module process.

Tip  To access databases on another computer, provide the path in the format \\computer\database_name. For example, if you have a copy of the 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.
shared variable names is the list of shared variable names corresponding to the historical traces for which you want to read historical data. The DSC Module uses these shared variable names as column headers when you convert this information into spreadsheet format.
time interval is the span of time between the start timestamp and stop timestamp. If you do not wire this input, the VI reads all data logged up to now.
start timestamp is the start date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged before the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the first data point in the database.

stop timestamp is the end date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged after the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the last data point in the database.

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.
options specifies the formatting settings for the data as the VI reads the trace or traces.
interpolate data estimates data values based on the data values that were logged at the interpolation interval.
extrapolate to now extrapolates the last data point in the database to the current system time when TRUE. If the last point logged was a break (logging was turned off), no point is added unless remove data breaks is also TRUE.
remove data breaks removes the value of a data break from the trace. When this value is FALSE, gaps in the logged data are preserved, marked by a break. If this value is TRUE, the break markers are not placed in the trace, which means you can no longer identify the gaps in the data.
maintain trending info includes the last data point before start timestamp and the first data point after stop timestamp with the returned trace if TRUE. If this parameter is FALSE, the returned trace includes only points strictly between start timestamp and stop timestamp.
interpolation interval is the interval at which the VI interpolates the data in seconds.
database URL out is the computer name and database name.
historical traces is the trace data for each input tag name read from the historical database, starting at the date and time specified by start timestamp and stopping at the date and time specified by stop timestamp or up to max points per trace, whichever is smaller. If the start timestamp and stop timestamp values are unwired, all the logged data up to max points per trace for the tag is returned.
timestamps returns the timestamp of the most recent shared variable value for each value in the shared variable name array.
data contains the data values of the data points.
quality is the data quality of the trace(s) read. A value of zero indicates good quality.
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.

Read Traces (Bit Array)

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.
max points per trace is the maximum number of points to read from the database. The default is –1. If max points per trace is less than zero, the VI returns all points available between start timestamp and stop timestamp. Otherwise, the number of points in the trace is the minimum of the actual number of data points between start timestamp and stop timestamp and max points in trace (all).
database URL is the computer name where the Citadel database resides and the name of the database. Enter the database URL in the format \\computer\database_name. If you do not wire database URL, the VI reads data from the database associated with the default DSC Module process.

Tip  To access databases on another computer, provide the path in the format \\computer\database_name. For example, if you have a copy of the 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.
shared variable names is the list of shared variable names corresponding to the historical traces for which you want to read historical data. The DSC Module uses these shared variable names as column headers when you convert this information into spreadsheet format.
time interval is the span of time between the start timestamp and stop timestamp. If you do not wire this input, the VI reads all data logged up to now.
start timestamp is the start date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged before the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the first data point in the database.

stop timestamp is the end date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged after the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the last data point in the database.

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.
options specifies the formatting settings for the data as the VI reads the trace or traces.
interpolate data estimates data values based on the data values that were logged at the interpolation interval.
extrapolate to now extrapolates the last data point in the database to the current system time when TRUE. If the last point logged was a break (logging was turned off), no point is added unless remove data breaks is also TRUE.
remove data breaks removes the value of a data break from the trace. When this value is FALSE, gaps in the logged data are preserved, marked by a break. If this value is TRUE, the break markers are not placed in the trace, which means you can no longer identify the gaps in the data.
maintain trending info includes the last data point before start timestamp and the first data point after stop timestamp with the returned trace if TRUE. If this parameter is FALSE, the returned trace includes only points strictly between start timestamp and stop timestamp.
interpolation interval is the interval at which the VI interpolates the data in seconds.
database URL out is the computer name and database name.
historical traces is the trace data for each input tag name read from the historical database, starting at the date and time specified by start timestamp and stopping at the date and time specified by stop timestamp or up to max points per trace, whichever is smaller. If the start timestamp and stop timestamp values are unwired, all the logged data up to max points per trace for the tag is returned.
timestamps returns the timestamp of the most recent shared variable value for each value in the shared variable name array.
data contains the data values of the data points.
quality is the data quality of the trace(s) read. A value of zero indicates good quality.
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.

Read Traces (Logical)

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.
max points per trace is the maximum number of points to read from the database. The default is –1. If max points per trace is less than zero, the VI returns all points available between start timestamp and stop timestamp. Otherwise, the number of points in the trace is the minimum of the actual number of data points between start timestamp and stop timestamp and max points in trace (all).
database URL is the computer name where the Citadel database resides and the name of the database. Enter the database URL in the format \\computer\database_name. If you do not wire database URL, the VI reads data from the database associated with the default DSC Module process.

Tip  To access databases on another computer, provide the path in the format \\computer\database_name. For example, if you have a copy of the 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.
shared variable names is the list of shared variable names corresponding to the historical traces for which you want to read historical data. The DSC Module uses these shared variable names as column headers when you convert this information into spreadsheet format.
time interval is the span of time between the start timestamp and stop timestamp. If you do not wire this input, the VI reads all data logged up to now.
start timestamp is the start date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged before the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the first data point in the database.

stop timestamp is the end date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged after the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the last data point in the database.

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.
options specifies the formatting settings for the data as the VI reads the trace or traces.
interpolate data estimates data values based on the data values that were logged at the interpolation interval.
extrapolate to now extrapolates the last data point in the database to the current system time when TRUE. If the last point logged was a break (logging was turned off), no point is added unless remove data breaks is also TRUE.
remove data breaks removes the value of a data break from the trace. When this value is FALSE, gaps in the logged data are preserved, marked by a break. If this value is TRUE, the break markers are not placed in the trace, which means you can no longer identify the gaps in the data.
maintain trending info includes the last data point before start timestamp and the first data point after stop timestamp with the returned trace if TRUE. If this parameter is FALSE, the returned trace includes only points strictly between start timestamp and stop timestamp.
interpolation interval is the interval at which the VI interpolates the data in seconds.
database URL out is the computer name and database name.
historical traces is the trace data for each input tag name read from the historical database, starting at the date and time specified by start timestamp and stopping at the date and time specified by stop timestamp or up to max points per trace, whichever is smaller. If the start timestamp and stop timestamp values are unwired, all the logged data up to max points per trace for the tag is returned.
timestamps returns the timestamp of the most recent shared variable value for each value in the shared variable name array.
data contains the data values of the data points.
quality is the data quality of the trace(s) read. A value of zero indicates good quality.
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.

Read Traces (String)

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.
max points per trace is the maximum number of points to read from the database. The default is –1. If max points per trace is less than zero, the VI returns all points available between start timestamp and stop timestamp. Otherwise, the number of points in the trace is the minimum of the actual number of data points between start timestamp and stop timestamp and max points in trace (all).
database URL is the computer name where the Citadel database resides and the name of the database. Enter the database URL in the format \\computer\database_name. If you do not wire database URL, the VI reads data from the database associated with the default DSC Module process.

Tip  To access databases on another computer, provide the path in the format \\computer\database_name. For example, if you have a copy of the 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.
shared variable names is the list of shared variable names corresponding to the historical traces for which you want to read historical data. The DSC Module uses these shared variable names as column headers when you convert this information into spreadsheet format.
time interval is the span of time between the start timestamp and stop timestamp. If you do not wire this input, the VI reads all data logged up to now.
start timestamp is the start date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged before the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the first data point in the database.

stop timestamp is the end date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged after the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the last data point in the database.

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.
options specifies the formatting settings for the data as the VI reads the trace or traces.
interpolate data estimates data values based on the data values that were logged at the interpolation interval.
extrapolate to now extrapolates the last data point in the database to the current system time when TRUE. If the last point logged was a break (logging was turned off), no point is added unless remove data breaks is also TRUE.
remove data breaks removes the value of a data break from the trace. When this value is FALSE, gaps in the logged data are preserved, marked by a break. If this value is TRUE, the break markers are not placed in the trace, which means you can no longer identify the gaps in the data.
maintain trending info includes the last data point before start timestamp and the first data point after stop timestamp with the returned trace if TRUE. If this parameter is FALSE, the returned trace includes only points strictly between start timestamp and stop timestamp.
interpolation interval is the interval at which the VI interpolates the data in seconds.
database URL out is the computer name and database name.
historical traces is the trace data for each input tag name read from the historical database, starting at the date and time specified by start timestamp and stopping at the date and time specified by stop timestamp or up to max points per trace, whichever is smaller. If the start timestamp and stop timestamp values are unwired, all the logged data up to max points per trace for the tag is returned.
timestamps returns the timestamp of the most recent shared variable value for each value in the shared variable name array.
data is contains the data values of the data points.
quality is the data quality of the trace(s) read. A value of zero indicates good quality.
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.

Read Traces (Variant)

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.
max points per trace is the maximum number of points to read from the database. The default is –1. If max points per trace is less than zero, the VI returns all points available between start timestamp and stop timestamp. Otherwise, the number of points in the trace is the minimum of the actual number of data points between start timestamp and stop timestamp and max points in trace (all).
database URL is the computer name where the Citadel database resides and the name of the database. Enter the database URL in the format \\computer\database_name. If you do not wire database URL, the VI reads data from the database associated with the default DSC Module process.

Tip  To access databases on another computer, provide the path in the format \\computer\database_name. For example, if you have a copy of the 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.
shared variable names is the list of shared variable names corresponding to the historical traces for which you want to read historical data. The DSC Module uses these shared variable names as column headers when you convert this information into spreadsheet format.
time interval is the span of time between the start timestamp and stop timestamp. If you do not wire this input, the VI reads all data logged up to now.
start timestamp is the start date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged before the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the first data point in the database.

stop timestamp is the end date and time of data you want to retrieve from the database. The DSC Module retrieves the entire page on which the data appears. When you view the data, you might see data logged after the actual time you specified.

If you do not wire this input, the DSC Module uses the timestamp of the last data point in the database.

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.
options specifies the formatting settings for the data as the VI reads the trace or traces.
interpolate data estimates data values based on the data values that were logged at the interpolation interval.
extrapolate to now extrapolates the last data point in the database to the current system time when TRUE. If the last point logged was a break (logging was turned off), no point is added unless remove data breaks is also TRUE.
remove data breaks removes the value of a data break from the trace. When this value is FALSE, gaps in the logged data are preserved, marked by a break. If this value is TRUE, the break markers are not placed in the trace, which means you can no longer identify the gaps in the data.
maintain trending info includes the last data point before start timestamp and the first data point after stop timestamp with the returned trace if TRUE. If this parameter is FALSE, the returned trace includes only points strictly between start timestamp and stop timestamp.
interpolation interval is the interval at which the VI interpolates the data in seconds.
database URL out is the computer name and database name.
historical traces is the trace data for each input shared variable name read from the historical database, starting at the date and time specified by start timestamp and stopping at the date and time specified by stop timestamp or up to max points per trace, whichever is smaller. If you do not wire the start timestamp and stop timestamp values, this VI returns all the logged data up to max points per trace for the shared variables.
timestamps returns the timestamp of the most recent shared variable value for each value in the shared variable name array.
data contains the data values of the data points.
quality is the data quality of the trace(s) read. A value of zero indicates good quality.
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.

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