The EXCEL application must have access to the WebAccess SCADA node. EXCEL must be running on the SCADA Node PC or have a Network DDE connection (NetDDE) to the SCADA node.
In EXCEL, the formula has three parts: the name of the application (bwdde); the file name or topic always topic for WebAccess); and the cell range, value, field, or data that's referred to (the tagname). The following illustration shows the parts of a remote reference formula and the required separator characters.
A pipe character (|) separates the program name from the document or topic name. An exclamation point (!) separates the document or topic name from the cell range, value, field, or data referred to.
The general format of EXCEL formula to read data from WebAccess is:
=bwddexe|topic!tagname
=bwddexe|topic!tagname.field
=bwddexe|topic!BLOCK:PARAMETER
=bwddexe|topic!BLOCK:PARAMETER.field
For example,
To read the value of the tag named
speed:
=bwddexe|topic!SPEED.NAME
To read the Hi Span of a tag name
speed:
=bwddexe|topic!SPEED.SPANHI
To read the engineering units of
TIMER
: =bwddexe|topic!TIMER.ENUNIT
When to use
single quotation marks In EXCEL, if the name of the
tag item contains spaces, begins with a number or contains
characters such as underscore (_), colons (:) or minus signs ( – )
or contains characters that have special uses in a formula, or if a
name resembles a cell reference, enclose the name in single
quotation marks.
For example,
=bwddexe|topic!'1Z_1_TEXT'