The network DDE Client specifies the remote DDE server share in the normal DDE Client syntax by replacing the DDE Application name and DDE Topic name with the DDE server computer name and DDE server share name in the call. For DDE client syntax details, see DDE conversations and client syntax.
With Network DDE Client syntax, the DDE Application name is replaced with the following string enclosed in single quotes:
where "<ComputerName>" is the name of the computer running the DDE server application, and "NDDE$" notifies Windows on the remote computer that the calling DDE Client wishes to establish a Network DDE channel. You cannot omit the NDDE$ string, or it won't work.
The DDE Topic name is replaced with the following string also enclosed in single quotes:
where "<ShareName>" is the name of the DDE Trusted Share previously set-up on the DDE server computer. The DDE Share on the DDE server machine contains the details of which application and topic to create the Network DDE link with. Most often, DDE server share names end with a $ character.
Note: You need to use a separate DDE share name on the remote computer for each combination of DDE application name and DDE topic name you want to share. You can not declare the topic as a wild card (*).
For example, to create a Network DDE link with the following criteria:
you would construct a Network DDE Client call containing:
In Excel, the following formula could be placed directly into a worksheet cell:
If prompted for a username and password, use one that has appropriate permissions on the DDE server computer.
Note: You cannot omit the DDE syntax pipe character (|) or exclamation character (!), nor can you enclose those characters within quotes (').
CitectSCADA comes with an Excel workbook file which contains macros to help you insert correct DDE Client syntax links from your CitectSCADA runtime project tag database directly into an Excel worksheet.