int _stdcall monitor_status(int camera, const char * content, unsigned int content_len, DWORD wait_time);
camera:[in]，The camera's handle which is from new_camera
content:[in]，One or more camera status which want to monitor
content_len:[in]，The monitor content's length
wait_time:[in]，The time waiting for repone, millisecond
Return ERROR_OK if success，else refer to the definition of error number
Request monitor the state of the camera.
Before calling this function, should first ensure the connection of camera
with the specified has been established, or the operation will fail.
This function is one or more state request monitor camera to camera,
the result of the operation through the MONITOR_STATUS_RESULT event notification user.
When the operation is successful, if a user specified monitor changes, camera will notify the client program.
After receiving the rc_ipcam library can stimulate the MONITORED_STATUS_CHANGED event to notify the user.
For example, a user can request to monitor camera disk, record, alarm,
So once the camera disk or tape or alarm status changes,
The user can through paying attention to the camera MONITORED_STATUS_CHANGED event to get.
The content parameter is used to specify the name of the state to monitor.
The format of the content parameter is composed of one or more strings,
Each string is composed to monitor the state name, between each string '\0' separated by.
The content_len parameter value is equal to the length of all the data of content, including each end of the string '\0'.
Content = "disk\0record\0alarm\0"; (Note: Here "" does not mean that the content of C string, just represent the distribution in memory)
Content_len 18.
As for the specific state of camera please refer to the relevant CGI application guide.