1. Select "DDE Server" from WinWedge MODE
menu. When the dialog box appears asking for a DDE Command
Destination Application, enter: MyServer as the Application
Name and enter MyTopic as the DDE topic.
2. Select "Input Data Record Structure" from
the DEFINE menu and define the structure of the input records
to WinWedge. When you get to the final Window entitled "Input
Record Definition Editor", enter the string: [GRABDATA] as
the "Field Postamble DDE Command" after the last
data field that you have defined. This is a DDE command that
will be sent to your FoxPro application after each data record
is received by the Wedge.
3. Set up the rest of WinWedge parameters and activate
it.
FoxPro does not have a "GrabData" command
so we must create one. The FoxPro code example on the following
page does exactly that. Create a new program module in the
CODE section of FoxPro and enter the code on the following
page. After you are done entering the code save your work
and run the program.
What this example does is to set up WinWedge to issue a
DDE command [GRABDATA] to your FoxPro application
after each data record is received from your serial device.
This causes the procedure DoCommand to run which then
performs a DDERequest back to the Wedge asking for the data
in Field(1) in the Wedge Window. This data is then returned
to FoxPro in the variable: MyData. Once the data from the
Wedge is in a variable, you can do whatever you like with
it by including additional code of your own design.
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*** Set this application up as a DDE server. The following
code must be run at the start***
*** of your application to make it able to respond to DDE commands.***
*** Set the DDE application name to: "MyServer" and Enable DDE command
execution***
= DDESetService('MyServer', 'DEFINE')
= DDESetService('MyServer', 'EXECUTE', .T.)
*** Set the DDE topic to "MyTopic" ***
*** Set up procedure "DoCommand" to run on all DDEExecutes to topic
"MyTopic"***
= DDESetTopic('MyServer', 'MyTopic', 'DoCommand')
*** The following procedure will run whenever another application***
*** issues a DDE command to application name 'MyServer' and topic 'MyTopic'***
*** The DDE command is passed in the variable "gData"***
PROCEDURE DoCommand
PARAMETERS gnChannel, gcAction, gcItem, gData, gcFormat,
gnAdvise
glResult = .F.
*** It's necessary to return .T. from an INITIATE action or no connection is made ***
IF gcAction = 'INITIATE'
glResult = .T.
ENDIF
IF gcAction = 'EXECUTE'
*** support a GRABDATA command - performs a DDERequest to WinWedge***
*** on COM2, requests data from FIELD(1) and stores it in a variable:
"MyData"***
IF gData="[GRABDATA]"
gnChanNum = DDEInitiate('WinWedge', 'COM2')
IF gnChanNum != -1
MyData=DDERequest(gnChanNum,'Field(1)')
= DDETerminate(gnChanNum) && Close the channel
*** The variable 'MyData' now contains the data from Field(1) in WinWedge***
*** Your code goes here to do something with it ***
WAIT WINDOW MyData NOWAIT && For Example - Display the data
ENDIF
ENDIF
ENDIF
IF gcAction = 'TERMINATE'
glResult = .T.
ENDIF
RETURN glResult
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