Computer system with work stations at remote positions and reserve battery power supply

• US 4,841,474 A
• Filed: 05/10/1985
• Issued: 06/20/1989
• Est. Priority Date: 05/15/1984
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Van Der Vliet, Peter C. L., Zandveld, Frederik
• Primary Examiner(s): Shaw, Gareth D.
• Assistant Examiner(s): KULIK, PAUL V
• Application Number:
  US06/733,272
• Time in Patent Office: 1,502 Days
• Field of Search: 365/228, 365/229, 371/7, 371/9, 371/10, 371/12, 371/66, 364/200, 364/900, 364/492, 364/493, 364/569, 364/144, 364/145, 364/187, 364/146, 307/64, 307/66
• US Class Current: 714/14
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision

Abstract

A computer system having a central machine, work stations and a background memory, wherein the central machine has an active state, a standby state, a battery power supply state and a rest state, a heart memory maintains the actual time and contains information indicating at what time of what days the active state should prevail. When the mains power supply fails the central machine goes over to the battery power supply state. When the latter is failing, the battery indicator is set in an "error" state. When the mains power supply reappears, it is inspected whether then the active state has to be maintained and under the control of an "error" position an initial program load operation is carried out. If admissible the central machine goes over to the standby state.

Claims

1. A computer system comprising:

a central machine for processing data, said machine being adapted to be connected to a mains supply, said central machine including a volatile memory;

a plurality of user work stations coupled to said central machine for remote users to exchange data with said central machine;

reserve battery supply means connected to said central machine for temporarily supplying power to said volatile memory in the event said mains supply is interrupted;

said central machine having four separate states;

an active state, in which data exchange by said central machine with any of said work stations, including processing at said central machine can be carried out;

a standby state, in which data exchange cannot be carried out between any of said workstations and said central machine but in which the volatile memory is powered by the mains supply for retaining information;

a battery supply state in which the volatile memory is temporarily powered by the reserve battery supply means for retaining information; and

a rest state, during which the central machine and volatile memory are deactivated and information stored in the volatile memory is lost;

independently powered heart memory means operative during all said states for storing predetermined beginning and ending times for the active state and including real time clock means and means for setting said central machine in said active state during an active time period beginning at said beginning time and ending at said ending time;

each said workstation including user control means for generating an activate state request signal requesting to change the state of said central machine from said standby state to said active state;

means for generating a battery-was-off signal in the event power from said reserve battery supply means was interrupted during said battery supply state;

means, including said heart memory means, for storing indications of the condition of said computer system including said battery-was-off signal and an indication of whether an activate state request signal has occurred; and

logic means responsive to the presence of power from said mains supply for selectively placing said central machine in said active state or said standby state based on inspection of said stored condition indications including means for initiating an initial program load if said mains supply power reappears during said active time period and said battery-was-off signal is present.

2. The computer system of claim 1 wherein the activate state request signal produced by each said user control means is momentary and wherein said indications storing means includes means responsive to said momentary activate state request signal for storing a RUN signal indicating that a momentary activate state request signal has occurred;

and wherein said logic means responsive to the presence of power from said mains supply also comprises means for initiating said initial program load in the presence of said RUN signal dependent on the state of said battery-was-off signal.

3. The computer system of claim 1 wherein said indication storing means includes means for storing a RESTART VALID signal in said heart memory means if an operation interrupted by failure of said main supply can be continued.

4. The computer system of claim 3 wherein said logic means further comprises means responsive to said RESTART VALID signal to put the central machine in the active state and initiate a RESTART operation upon the reappearance of power from said mains supply.

5. The computer system of claim 2 further comprising means for terminating the active state if said active time period has ended and no new activate state request signal is detected during a predetermined period.

6. The computer system of any of claims 1, 2 or 4 wherein said indications storing means further comprises means for storing a SLEEP signal in said heart memory and wherein said logic means also comprises means responsive to the presence of said SLEEP signal for putting said central machine in the standby state on the reappearance of power from said mains supply and in the absence of the battery-was-off signal.

7. The computer system of any of claims 1-5 further comprising operator selectable means for initializing data stored in said heart memory means except for said beginning and ending times.

8. The computer system of any of claims 1-5 wherein said heart memory means stores different beginning and ending times for a plurality of different days.

9. The computer system of claim 1 further comprising a control panel for a system operator including a first activating element having "on" and "off" positions for selectively placing said central machine in the rest state and a second activating element for generating an activate state request signal, said second activating element also comprising means for selectively locking said first activating element in position.

10. The computer system of claim 1 further comprising a control panel which includes selector means having at least two positions for selecting one of at least two sources in said computer system from which said initial program is to be loaded.

11. The computer system of claim 10 wherein said selector means has a further position for selecting said volatile memory as a source the initial program load.