acking and automatically communicating printer failures and usage profile aspectsUS6330628Jun 23, 1997Dec 11, 2001Ricoh Company, Ltd.Memory including a data structure used for identifying a communication protocol of a received communicationUS6430711Jan 6, 1999Aug 6, 2002Seiko Epson CorporationSystem and method for monitoring the state of a plurality of machines connected via a computer networkUS64