Method of controlling a set point

• US 4,527,230 A
• Filed: 07/29/1983
• Issued: 07/02/1985
• Est. Priority Date: 08/18/1982
• Status: Expired due to Fees

• Current Assignee: Sony/Tektronix Corporation (Fortive Corp.)
• Original Assignee: Sony/Tektronix Corporation (Fortive Corp.)
• Inventors: Takeuchi, Yoko, Sato, Keiichi, Yanagisawa, Midori
• Primary Examiner(s): RUGGIERO, JOSEPH F
• Application Number:
  US06/518,581
• Time in Patent Office: 704 Days
• Field of Search: 364/130, 364/188, 364/189, 364/190, 340/347 P, 340/354, 340/364, 340/365 R
• US Class Current: 700/1
• CPC Class Codes: G01D 5/2497 Absolute encoders G01D5/2454 takes precedence
• CPC Class Codes: G01R 31/2834 Automated test systems [ATE]; using microprocessors or computers G01R31/317 takes precedence; ATE for detection of defective computer hardware G06F11/2736
• CPC Class Codes: G05B 19/108 characterised by physical layout of switches; switches co-operating with display; use of switches in a special way

Abstract

A set point control method and apparatus for controlling many set points of an electronic apparatus by using a simple switch is disclosed. A switch condition is repeatedly detected, and a difference of the switch conditions is obtained when a former switch condition is different from the present switch condition. If a switch is a rotary digital switch for selecting one of a plurality of digital words, the difference is defined by the rotation direction of the switch and a difference of the former and present digital words. A memory stores a plurality of set information, and is addressed in accordance with the difference for controlling the set point of the electronic apparatus.

Claims

1. In a method of controlling a set point with a rotary switch for generating sequentially a predetermined number of different digital words by a single rotation thereof, each of said digital words corresponding to zero or a positive number less than said predetermined number, the method comprising the steps of:

periodically detecting digital words from said rotary switch;

comparing a newly-detected first digital word with a previously-detected second digital word and obtaining the difference therebetween;

obtaining a change value according to the difference between said first digital word and said second digital word under any one of the following four conditions;

(1) when the first digital word is less than the second digital word, and said difference is less than one-half of said predetermined number, then the change value is equal to the negative of said difference;

(2) when the first digital word is less than the second digital word, and said difference is greater than one-half of said predetermined number, then the change value is equal to said predetermined number minus said difference;

(3) when the first digital word is greater than the second digital word, and said difference is greater than one-half of said predetermined number, then the change value is equal to said difference minus said predetermined number;

(4) when the first digital word is greater than the second digital word, and said difference is less than one-half of said predetermined number, then the change value is equal to said difference; and

controlling the set point in accordance with said obtained change value.

2. A method in accordance with claim 1 wherein a presently obtained change value is added to a previous set-point control value to derive a new set-point control value.

3. A method in accordance with claim 2 wherein said new set-point control value is set to the maximum or minimum value of a predetermined control value range if said new set-point control value is outside of control value range.