opcif_unregister()
#include opcapi.h
int opcif_unregister(
int interface_id, /* in */
long cond_id /* in */
);
Parameters
interface_id- Specifies which interface instance is used.
cond_id- Specifies the registration condition to be removed; 0 unregisters for all messages, message events or application responses.
Description
To cancel prior registrations for messages, the external
application calls
opcif_unregister() with the value of reg_cond that was
specified in the call to the registration API. As the registration
mechanism is a positive filter, removing a registration condition
does not mean that messages matched by this condition are filtered
out after opcif_unregister() is called; instead, just
that positive filter condition is cancelled.
By unregistering a condition for message events or application responses, information matching the unregistered condition will no longer received.
Return Values
OPC_ERR_OK:- OK
OPC_ERR_CANT_INIT:- initialization of queues failed
OPC_ERR_INVALID_INTERFACE_ID:- no such interface opened
OPC_ERR_CANT_INFORM_MSGM:- informing message manager failed
Versions
HPOM for Windows A.07.50 and later
See Also