TagExDesc

For an attribute associated with a PI point, retrieve the point's extended descriptor from the point database.

Syntax

TagExDesc(attname)

Arguments

• attname

  An attribute with a PI point data reference, enclosed in single quotes

Returns

The PI point's extended descriptor

Exceptions

If the PI point does not exist, an error values is returned

Notes

Returns blank when PI point lacks extended descriptor

Example

• TagExDesc('cdt158')

  [Returns blank since the point lacks extended descriptor]