Remote power control

(54) REMOTE POWER CONTROL

(75) Inventors: Reginald Beer, Eastleigh (GB); Robert Frank Maddock, Southampton (GB); Michael Alan Veal, Southampton (GB)

(73) Assignee: International Business Machines Corporation, Armonk, NY (US)

( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.

(21) Appl. No.: 09/548,025

(22) Filed: Apr. 12, 2000

(30) Foreign Application Priority Data

Dec. 23, 1999 (GB) 9930284

(51) Int. CI.7 G06F 1/26; G06F 1/32

(52) U.S. CI 340/3.1; 713/300; 713/310;

713/320; 713/323; 713/324

(58) Field of Search 340/3.1; 713/300,

713/323, 322, 321, 310, 320, 324

(56) References Cited

U.S. PATENT DOCUMENTS

4,747,041 A * 5/1988 Engel et al 307/29

4,835,706 A * 5/1989 Asahi 340/3.1

5,404,544 A * 4/1995 Crayford 713/310

5,408,668 A 4/1995 Tornai

5,483,464 A * 1/1996 Song 307/38

5,489,809 A 2/1996 Kaya et al.

5,713,027 A * 1/1998 Soejima et al 709/224

5,919,263 A * 7/1999 Kikinis et al 713/300

5,936,442 A 8/1999 Liu et al.

5,974,551 A * 10/1999 Lee 713/300

5,978,923 A * 11/1999 Kou 713/320

* cited by examiner

Primary Examiner—Brian Zimmerman
Assistant Examiner—Clara Yang

(74) Attorney, Agent, or Firm—Ido Tuchman; Louis P. Herberg

(57) ABSTRACT

A method is provided for remotely controlling power to electronic devices. Each device includes two or more ports for receiving signals over the serial link. The method includes issuing a shutdown command from the host data processing system to selected one ol the devices over the link and responsive to the receipt ol a power-off command at a device, causing the device to enter a low power standby mode on cessation ol signal activity at one ol the device ports. On entering standby mode at a device, standby power is supplied in the device to allow the device to monitor the one or more device ports lor incoming signals. In addition, transmission ol signals via the one or more ports is ceased. On receipt ol a signal at any ol the one or more ports that was previously inactive, power is restored to the device.

18 Claims, 3 Drawing Sheets