Overview of DDE and WinWedge

WinWedge has full support for Dynamic Data Exchange (DDE). This includes an advanced set of DDE commands that allow other Windows applications to take complete control of all WinWedge functions, including serial output functions. The DDE command set allows you to create extremely powerful device control interfaces from within any DDE supporting application, e.g. EXCEL, ACCESS, LOTUS, VB, INTOUCH, The FIX, some statistical software, LIMS, MMIs and many other Windows, Windows 95 and NT applications.

WinWedge Pro has an expanded set of DDE commands giving the user more precise control over all serial I/O functions directly from within your other Windows applications.

WinWedge can function as both a server and a client in conversations with other applications. As a server, the Wedge can supply data from the “Input Data Fields” and the Date/Time or Record# display fields in WinWedge window. It can also process DDE commands that are sent to it from other applications.

As a client, the Wedge can receive data or commands through an “Output Buffer Link” and a “DDE Command Link” . It can also issue commands to other applications that support a DDE command language. DDE commands can only be sent from the Wedge to another application as a “Record Preamble DDE Command” or as “Field Postamble DDE Commands” when it is in DDE Server Mode. Because the Wedge is the client in these conversations, it needs to know the DDE Application, Topic and Item Names for the Server program that it will be receiving data from or sending commands to. This is why the Wedge prompts you for a DDE Application Name and DDE Topic when you select “DDE Server” from the Mode menu.

Other applications can initiate DDE links with WinWedge using the DDE Application Name “WinWedge” and the DDE Topic “COMn” where “n” is the number of the serial adapter that the Wedge is activated for. The DDE Items available will be the contents of each defined input data field and the contents of the Date/Time and Record# display in WinWedge window. The DDE Item names for the data fields are referenced as “Field(1)” through “Field(n)” where “n” is the highest defined field number. The DDE Item name for the Date/Time display is “DATETIME” and the DDE Item name for the Record# display field is “RECORDNUMBER”. If you use the “Copy” & “Paste Link” method to initiate DDE conversations with WinWedge, this information will be automatically supplied to the client application and does not need to be explicitly specified.

WinWedge also has two hidden DDE Items with the names “OutputBuffer” and “CommandBuffer” that another application can use to “POKE” serial output data or DDE commands to the Wedge. DDE “Poking” is a process where a DDE client application sends data back to a DDE server item. Poking data to the OutputBuffer item would transmit the poked data out the serial port. Poking to the CommandBuffer performs the same function as sending a DDE Command to the Wedge.

To initiate DDE conversations with the Wedge from a macro in a spreadsheet or other application, you will have to refer to the user’s manual or on-line help for the specific application to learn the syntax of the commands or macro instructions that can be used to initiate DDE links, send DDE Commands, perform DDE Pokes or perform DDE Requests. Many example are provided in the “DDE Examples” and should therefore provide a good overview of how to communicate with the Wedge via DDE from within programs like Excel, Access, Lotus 123, Quattro Pro, FoxPro, Word and Visual Basic.

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