National Instruments 320682C Musical Toy Instrument User Manual


 
DDE Library Chapter 6
LabWindows/CVI Standard Libraries 6-6 © National Instruments Corporation
When the DDE_DATAREADY transaction is received in the callback function, a numeric
display is updated by passing the data pointer value to a numeric control on the UIR file.
When the DDE event is DDE_DISCONNECT, the DisconnectFromDDEServer
function ends the DDE conversation and program execution is halted.
DDE Library Function Reference
AdviseDDEDataReady
int
status = AdviseDDEDataReady
(unsigned int
conversationHandle
,
char
itemName
[], unsigned int
dataFormat
,
void
*
dataPointer
, unsigned int
dataSize
,
unsigned int
timeout
);
Purpose
Called by a server to write data to a DDE client application. The server should call this only
when the value of a data item changes, and a warm or hot link has been established for the data
item.
Parameters
Input
conversationHandle
unsigned integer Uniquely identifies the
conversation.
itemName
string Uniquely identifies the output
item; for example, system.
dataFormat
unsigned integer Valid data format; for example,
CF_TEXT.
dataPointer
void pointer Pointer to buffer holding data.
dataSize
unsigned integer Number of bytes in data. Must
be 0 if
dataPointer
is NULL.
Limited to 64 kbytes under
Windows 3.1 and Windows 95.
timeout
unsigned integer Timeout in ms.
Return Value
status
integer Refer to error codes in
Table 6-3.