KVM switch including a terminal emulator

• US 8,269,783 B2
• Filed: 07/24/2007
• Issued: 09/18/2012
• Est. Priority Date: 08/25/1999
• Status: Expired due to Fees

• Current Assignee: Avocent Redmond Corporation (Emerson Electric Company)
• Original Assignee: Avocent Redmond Corporation (Emerson Electric Company)
• Inventors: Shirley, Timothy C.
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): HOLTON, STEVEN E
• Application Number:
  US11/878,390
• Publication Number:
  US 20070291004A1
• Time in Patent Office: 1,883 Days
• Field of Search: 710/62, 710/100, 345/520
• US Class Current: 345/520
• CPC Class Codes: G06F 13/107 Terminal emulation
• CPC Class Codes: G06F 2203/0384 Wireless input, i.e. hardware and software details of wireless interface arrangements for pointing devices
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G09G 2370/24 Keyboard-Video-Mouse [KVM] switch
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04

Abstract

A method and system for converting the output of a communications port (e.g., a serial port or a USB port) into video signals representing the output of a terminal using a KVM switch. Upon receiving characters from the communications port, the system interprets the characters as terminal emulation commands and internally generates a representation of what a resulting terminal screen would look like. From that internal (digital) representation, the system produces analog outputs representing the terminal screen. The analog outputs are output on the monitor attached to the KVM switch.

Claims

1. A switch to communicate keyboard and video signals between a first remote target computer and a controlling user interface, comprising:

a target controller housing and (1) a plurality of target computer physical interfaces associated with the housing for coupling keyboard and video signals to or from the remote target computer via associated target computer interfaces and (2) a network physical interface associated with the housing for communication with a packet-based network;

a target controller within the target controller housing to translate keyboard and video signals between at least one of the target computer physical interfaces and the network physical interface;

a target controller communication device for communicating the keyboard and video signals using a packet-based communication protocol on the network physical interface wherein the controlling user interface operates to control the first remote target computer via a communication path including, in sequence, the network physical interface utilizing the packet-based communication protocol, the target controller, at least one of the target computer physical interfaces utilizing a computer peripheral protocol understood by the controlling user interface and different from the packet-based communication protocol, and the controlling user interface; and

a serial interface, separate from the plurality of target computer physical interfaces and separate from the network physical interface, for communicating with a second remote computer.

2. The switch as claimed in claim 1, wherein the serial interface comprises a serial interface for connecting to a null modem cable.

3. The switch as claimed in claim 1, wherein the serial interface comprises a serial interface for connecting to a modem connected to a telephone line.

4. The switch as claimed in claim 1, wherein the serial interface comprises a USB interface.

5. A switch to communicate keyboard and video signals between a first remote target computer and a controlling user interface, comprising:

a target controller housing and (1) a plurality of target computer physical interfaces associated with the housing for coupling keyboard and video signals to or from the remote target computer via associated target computer interfaces and (2) a network physical interface associated with the housing for communication with a packet-based network;

a target controller within the target controller housing to translate keyboard and video signals between at least one of the target computer physical interfaces and the network physical interface;

a target controller communication device for communicating the keyboard and video signals using a packet-based communication protocol on the network physical interface wherein the controlling user interface operates to control the first remote target computer via a communication path including, in sequence, the network physical interface utilizing the packet-based communication protocol, the target controller, at least one of the target computer physical interfaces utilizing a computer peripheral protocol understood by the controlling user interface and different from the packet-based communication protocol, and the controlling user interface; and

a parallel interface, separate from the plurality of target computer physical interfaces and separate from the network physical interface, for communicating with a second remote computer.

6. A switch to communicate keyboard and video signals between a first remote target computer and a controlling user interface, comprising:

a target controller housing and (1) a plurality of target computer physical interfaces associated with the housing for coupling keyboard and video signals to or from the remote target computer via associated target computer interfaces and (2) a network physical interface associated with the housing for communication with a packet-based network;

a target controller within the target controller housing to translate keyboard and video signals between at least one of the target computer physical interfaces and the network physical interface;

a target controller communication device for communicating the keyboard and video signals using a packet-based communication protocol on the network physical interface wherein the controlling user interface operates to control the first remote target computer via a communication path including, in sequence, the network physical interface utilizing the packet-based communication protocol, the target controller, at least one of the target computer physical interfaces utilizing a computer peripheral protocol understood by the controlling user interface and different from the packet-based communication protocol, and the controlling user interface; and

a wireless interface, separate from the plurality of target computer physical interfaces and separate from the network physical interface, for communicating with a second remote computer.