IM-Based Communication Mechanism for an On-Line Monitoring System

There was a problem that monitoring server (MS) maybe could not originate active communications to monitoring terminals (MT) which use private IP addresses in an on-line monitoring system for scientific instruments (OMS-SI) based on Internet/Intranet, so instant messaging (IM) used for near-real-time text-based chatting originally was introduced to provide a new communication mechanism for OMS-SI. In the IM-based communication mechanism, MS can obtain current presence (online/offline, available/unavailable, etc.) of every MT and communicate with it actively if the MT is available, even though private IP address is used for the MT. This communication mechanism for OMS-SI proposed in this paper is also valuable for designing intelligent sensor or other on-line monitoring system based on Internet/Intranet.