registerPoint
registerPoint — registers to receive updates from a DataHub point.
ST_STATUS registerPoint( | point, | |
create); |
CDataHubPoint& point;bool create=TRUE;ST_STATUS registerPoint( | pointname, | |
create); |
LPCTSTR pointname;bool create=TRUE;Exception registerPoint( | point, | |
create); |
DataHubPoint point;boolean create;Exception registerPoint( | pointname, | |
create); |
String pointname;boolean create;Exception registerPoint( | point, | |
create); |
DataHubPoint point;bool create;Exception registerPoint( | pointname, | |
create); |
String pointname;bool create;pointA
DataHubPoint object. The name
member must be valid.
pointnameThe name of the point.
create If TRUE, then the point is created if it does
not already exist. If FALSE and the point does
not exist, then an error message will be generated.
ST_OK if the command was successfully sent to the
DataHub instance. Since the command is sent asynchronously, the actual
success or failure of the command must be determined through the onSuccess
or onError message handlers.
ST_NO_TASK if a connection to the DataHub instance
does not exist.
ST_ERROR if the connection socket is unable to
send the message.
When a point is registered with the DataHub instance, any changes to the value of
that point in the DataHub instance will cause the
onPointChange method to be called. If the
DataHub point does not exist, then DataHub instance will respond with an error, and
onError will be called with the
following arguments:
status: ST_NO_POINT |
msg: "Point does not exist" |