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Programming CP1413plus manual
7-80 Rev. 00/07
7.6.3.3.3 Fetch passive
#include <S5ACCESS.H>
USHORT WENTRY_C S5FetchPassiv(S5_PARAMS W_POINTER s5, S5_PARAMS
W_POINTER(WENTRY_C *UserFctCall)(S5_PARAMS W_POINTER s5))
The S5FetchPassiv function sends the data that a remote station requested by means of an active
fetch task.
Parameters
s5
pointer to a structure of the type
S5_PARAMS
. The values
Kennung, DB, DW
and
Len
of the
s5
structure must contain
valid entries.
s5
must contain a valid connection number which
was returned by the function
S5StarteVerbindung
.
Any data must be entered into a memory allocation located after the
s5 structure. You should allocate the maximum amount of memory
required for the requested data before calling the function. If the
amount of data referenced by
s5
is not available before the
function is initiated you may reallocate memory once the amount
has become available.
The function will either return a 0 or an H1 error.
Tab. 7-9 contains an overview of the H1 errors and their
description.
UserFctCall
pointer to the call-back function. Once the request has been
received from the remote station the requested data is supplied to
this function. The requested data is located in
Kennung, DB,
DW,
and
Len
of the
s5
structure that the initial function call
referred to. If the request from the remote station is not valid the
function will not be initiated and
S5FetchPassiv
is terminated
by an error. The remote station can be informed of errors (e.g.
invalid data requested) by means of
Fehler
in the call-back
function. Any errors are returned to the requesting remote station as
S5 error code, otherwise the data bytes are reversed and transferred
to the remote station. The data must be located in memory after the
s5
structure. The caller must supply the data by means of
references contained in
DB, DW a
nd
Kennung
. The length of
data is calculated from
Kennung
and
Len.
The User-Function is defined as follows:
S5PARAMS W_POINTER WENTRY_C UserCallback(
S5PARAMS W_POINTER s5);