DC_TAG dc_tag_add dc_tag_add_subscription DC_TAG_CALLBACK dc_tag_close dc_tag_error_code dc_tag_explain_quality DC_TAG_HANDLE dc_tag_init DC_TAG_MAX_RW_COUNT dc_tag_open dc_tag_read dc_tag_read_subscription dc_tag_remove dc_tag_remove_subscription dc_tag_uninit dc_tag_update dc_tag_write

DC_TAG_HANDLE dc_tag_open ( char const *  tag_name, void *  tag_context  ) Open a exist tag in the DataCenter with the specified name. Even the tag would be opened is not present in the DataCenter, this function also return a valid handle, but if you read the tag you would get a exception quality code. Parameters [in] tag_name Specify the name of the tag you want to add to the DataCenter. [in] tag_context The context related to the tag opened, it will be passed by the update callback function. Returns On success, a valid tag handle is returned, otherwise NULL is returned. Examples: dc_tag_read.c, dc_tag_read_subscription.c, dc_tag_update.c, and dc_tag_write.c.