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Programming CP1413plus manual
7-50 Rev. 00/07
7.6.2.3.13 Start reading expedited data and continue (asynchronous)
#include <H1Def.h>
unsigned short WENTRY_C H1StarteLesenExOverlapped(H1_RECPARAMS
W_POINTER rec, LPOVERLAPPED ov)
This function initiates a read task for expedited data. Expedited data is priority or urgent data.
This function initiates a read operation on an established connection and immediately returns to the
caller. The result of the function is returned in the rec structure. The completion of the read
operation (successful or error) is indicated by setting the event in the
ov
structure. You may also
check for completion of the read operation by means of the operating system function
H1GetOverlappedResult
.
Parameters
rec
pointer to a structure containing receive parameters. The parameters
Vnr
,
DataLen
and
SendLen(=0)
must be specified. The buffer
located at the end of the structure must have a length of
sizeof(H1_RECPARAMS) + DataLen
.
Possible values returned by
rec.Fehler
are:
0
H1_BLOCKED_DATA
H1_BAD_LINE
H1_WAIT_DATA
H1_NO_DRIVER
H1_NO_ADAPTER
H1_NOT_SUPPORTED
ov
pointer to a structure of the type
OVERLAPPED
. The
hEvent
must
be set to a handle for a valid event. The event must be created by the
user.
Returns
< >
0
An error has occurred in the operating system.
0
The rec.Fehler element contains one of the above values.
Note
This function initiates a read task. The result of the function can be checked by
means of
H1AbfrageLesenEx . You may not use both H1LeseDaten and
H1StarteLesen/H1AbfrageLesen
tasks for a single connection.
The driver must have been opened by means of H1DriverOpen and the respective
connection must have been established by means of
H1StarteVerbindung
.
See also
H1LeseDaten H1LeseDatenEx H1StarteLesenEx
H1StarteLesen H1AbfrageLesenEx H1AbfrageLesen
H1StarteLesenOverlapped H1GetOverlappedResult