WritePointValue

WritePointValue


Declaration

unsigned int _stdcall WritePointValue(struct StationPar * St, struct PointPar * Pt, struct KomUniVal * Val, unsigned int * RdBack)

Parameters

St

Pointer to the StationPar structure.

Pt

Pointer to the PointPar structure.

Val

Pointer to the KomUniVal structure (contains a new value).

RdBack

Pointer to a Boolean value of the request attribute of the function ReadPointValue.

Description

The function WritePointValue (_WritePointValue@16 in the Stdcall calling convention) is optional and called to write a new value into defined output I/O tag. After successful writing, the I/O tag will change into the status Transient (see the item Status in KomUniVal structure). The I/O tag will change back to the normal status (InLimit, ...) after the backward reading a value from the device. If a user requires the backward reading (calling the function ReadPointValue), it is necessary to write a non-zero value to into the parameter RdBack (if the parameter is zero, then calling the function ReadPointValue is disabled).

Return code

Code

Description

RQ_OK

Request executed OK.

RQ_ERR

An error occurred (a device does not communicate or is out of service, or there is any error), the station changes into the status COM_ERR or HARD_ERR after returning from the function.

RQ_IGNORED

The function was ignored and the station status is not changed.