DDE Functions

TN3270 Plus can function as a Dynamic Data Exchange (DDE) server. This allows DDE client applications to communicate with TN3270 Plus. For example, some users write Microsoft Excel macros to capture data from the TN3270 Plus terminal window and populate a spreadsheet. TN3270 Plus supports the following DDE functions:

Session Topic Functions

Use the session topic to send data to, and receive data from, a terminal session.

Connect	Service=tn3270,Topic=session name \| session#session_number Examples: Connect Service=tn3270,Topic=mainframe Connect Service=tn3270,Topic=session#3
	Return Values	Success: A handle to the conversation. Failure: 0
Execute	Item=close	closes the session.
	Item=macro macroname	executes a macro. macroname is the macro name.
	Item=script filename	executes a script. filename is the full path to the script to be executed.
	Return Values	Success: (HDDEDATA) DDE_FACK Failure: (HDDEDATA) DDE_FNOTPROCESSED
Request	Item=PS	returns the presentation space (screen image).
	Item=Cursor	returns the cursor position (relative to 1).
	Item=Rows	returns the number of rows in the presentation space.
	Item=Columns	returns the number of columns in the presentation space.
	Item=Emulator	returns the window handle of the TN3270 Plus window.
	Item=Keyboard	returns "Locked" if the keyboard is locked or else it returns "Clear".
	Item=OIA	returns the Operator Information Area (note that this is NOT in IBM format).
	Item=Rnn	returns the nth row in the presentation space.
	Item=Fnn	returns the nth field in the presentation space.
	Item=FnnU	returns the nth unprotected field in the presentation space.
	Item=FnnP	returns the nth protected field in the presentation space.
	Item=Pnnn[F\|Lmmm]	returns a portion of the presentation space. P = Identifier for starting position nnn = starting position on screen (relative to 1) F = return entire field at the starting position L = Identifier for length mmm = length of data to return Examples: P560 returns screen data from position 560 to the end of the field. P560F returns the entire field encompassing position 560. P560L80 returns data from position 560 for a length of 80 characters.
	Return Values	Success: A handle to the data being returned. Failure: 0
Poke	Item=Keystroke	sends one or more keystrokes to TN3270 Plus (same format as WinHLLAPI). See the Keystroke Table for a list of all the keystrokes.
	Item=Cursor	moves the cursor position (relative to 1).
	Item=EscChar	sets the escape character for Item=Keystroke (default is '@').
	Return Values	Success: (HDDEDATA) DDE_FACK Failure: (HDDEDATA) DDE_FNOTPROCESSED
Advise	Item=PS	sends the presentation space to the client whenever it is updated.
	Item=Cursor	sends the cursor position to the client whenever it is updated.
	Return Values	Success: (HDDEDATA) TRUE Failure: (HDDEDATA) FALSE

System Topic Functions

Use the system topic to send instructions to the TN3270 Plus application.

Connect Service=tn3270,Topic=system
	Return Values	Success: A handle to the conversation. Failure: 0
Execute	Item=connect session	connects to a session. session is the name of the session.
	Item=close session	closes a session. session is the name of the session.
	Item=key keyname	sends a menu key. keyname is the name of the menu key.
	Item=macro macroname	executes a macro. macroname is the macro name.
	Item=script filename	executes a script. filename is the full path to the script to be executed.
	Return Values	Success: (HDDEDATA) DDE_FACK Failure: (HDDEDATA) DDE_FNOTPROCESSED
Request	Item=activesession	returns the session number of the currently active session.
	Item=sessions	returns the total number of active sessions.

Tnrun.exe

The tnrun.exe program can execute DDE functions from an external script or program (e.g. Windows Script). The command line format is:

tnrun.exe SYSTEM|session_name command

Examples:

tnrun.exe SYSTEM connect mainframe	(Start the TN3270 Plus session "mainframe")
tnrun.exe mainframe macro login	(Run the "login" macro on session mainframe")

Sample Programs

Sample programs are available for download from the Customer Downloads page (http://sdisw.com/customer_downloads.htm) on our web site.

TN3270 Plus is continually being improved. To learn more about the latest enhancements, please review our Version History web page.