Archive Value function

Root path

The common path to specified data items, including those in expressions. Valid entries include:

• PI Data Archive server name if the data item is a PI point.

• PI AF server and database if the data item is a PI AF attribute.

• Blank if the data item is a PI point on the default PI Data Archive server.

  See Data items.

Data item(s)

One or more PI point names or PI AF attribute names, for which the function returns values.

To specify multiple data items, enter a range of cells that contain PI point names or PI AF attribute names. The function returns values for each.

Required if you select the Data item option.

Expression(s)

One or more performance equations that the function computes a value for. See Expressions.

To specify multiple expressions, enter a range of cells that contain complete expressions. The function returns values for each.

Required if you select the Expression option.

Time stamp

The time stamp for which the function returns values. Specify either a fixed time or a time expression relative to the current time. See Time inputs.

Required.

Retrieval mode

The method the function uses to determine returned values. Choices include:

• previous

  Returns the value that exactly matches or precedes the specified time stamp.

• previous only

  Returns the value that precedes the specified time stamp.

• interpolated

  Returns the interpolated value at the specified time.

  See Interpolated values.

• auto

  Returns the interpolated value at the specified time, or follows the previous method. (Uses the previous method for data items with step attributes.)

• next

  Returns the value that exactly matches or follows the specified time stamp.

• next only

  Returns the value that follows the specified time stamp.

• exact time

  Returns only a value that exactly matches the time stamp, or returns No events found if no value exists at that time stamp.

  Available if you select the Data item option.

Output cell

The worksheet cell where the function writes the resulting function array. If you select a cell before you open the function task pane, PI DataLink inserts the selected cell into the Output cell field.

Specify the top-left corner of the function array. PI DataLink expands the range downward and to the right of the output cell, as necessary to return specified data. PI DataLink might overwrite adjacent cells.

If you specify a multi-cell array in the Output cell field and the specified array is larger than the resulting function array, PI DataLink pastes the function formula in the unneeded cells of the specified array.

No time stamp

Select this option to return only values. The function returns values in a column for a column of referenced data items or expressions, or returns values in a row for a row of referenced data items or expressions.

Time at left

Click this option to return two columns: the time stamp in the left column and the value in the right column.

Time on top

Click this option to return two rows: the time stamp in the top row and the value in the bottom row.