1. Filed of the Invention
The present invention relates to a technique of making a diagnosis of abnormality in a device in the event of a communication failure between the device and a server.
2. Description of the Related Art
Monitor systems have been proposed recently to use a server to monitor multiple printers located in an intranet via the Internet.
In the proposed monitor system, the intranet is connected via a proxy server to the Internet. A firewall is set in the proxy server to block unauthorized accesses from the Internet and interfere with a direct access from the server to the intranet. Each of the multiple printers located in the intranet thus voluntarily makes an access to the server via the Internet and informs the server of a result of the self monitoring.
A known technique related to the monitor system enables a client to monitor copying machines via a communication device as disclosed in Japanese Patent Laid-Open Gazette No. 2002-288066.
In the prior art monitor system, when a printer included in the intranet has some abnormality and fails to access to the server (in the event of a communication failure between the server and the printer), the server can not make a diagnosis of abnormality in the printer because of the interference with the direct access from the server to the intranet.
The monitor system may be adopted to monitor diversity of other devices as well as the printers, and similar problems may occur in any of such monitor systems.