Browse Prior Art Database

Indicator Control System

IP.com Disclosure Number: IPCOM000081297D
Original Publication Date: 1974-May-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Baldwin, BE: AUTHOR

Abstract

Indicating systems for showing the status of various elements in a system should preferably have the ability to freeze the pertinent data displayed at the time of failure, so that maintenance personnel can determine the status of the system at the time the failure occurred. Capture of status by this indicator control system meets the following requirements: (1) The data captured or frozen is not changed during the period extending from system failure to logging of status by maintenance personnel. (2) Assuming the failure is intermittent and resettable, machine operation is allowed to continue. (3) Indicated data can be understood by maintenance personnel without referral to manuals or handbooks for meaning of indications. (4) Logout analysis is accomplished while the system continues to operate.

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Indicator Control System

Indicating systems for showing the status of various elements in a system should preferably have the ability to freeze the pertinent data displayed at the time of failure, so that maintenance personnel can determine the status of the system at the time the failure occurred. Capture of status by this indicator control system meets the following requirements:
(1) The data captured or frozen is not changed during the

period extending from system failure to logging of status

by maintenance personnel.
(2) Assuming the failure is intermittent and resettable, machine

operation is allowed to continue.
(3) Indicated data can be understood by maintenance personnel

without referral to manuals or handbooks for meaning of

indications.
(4) Logout analysis is accomplished while the system continues

to operate.

As shown, a plurality of data lines, to be indicated, such as +D1, +D2, +D3...+Dn are connected as inputs to a corresponding plurality of polarity hold latches, such as PHL1, PHL2, PHL3...PHLn. These latches are constructed and arranged so that a signal on the +D line will cause an output to be present on the output line, and if the signal on the input line changes, the output signal follows. However, these conditions obtain only if the common line CL is up, as during normal operation. Occurrence of a system error or failure causes a latch IL to be set on, thereby dropping line CL, and "freezing" the output of each polarity hold latch in its condi...