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 KomUniValstructure). 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.
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