US 6,118,387 A · Counter

Abstract

When a cylinder is urged to displace a piston rod, and a pulse signal is inputted into a counter from an encoder, then the number of pulses of the pulse signal is counted by a counting section. A time-measuring section starts measurement for the elapsed time upon the start of operation of the cylinder. When the pulse signal is inputted, the elapsed time is reset. When the displacement of the piston rod is stopped, the pulse signal is not inputted. The elapsed time is increased to make coincidence with a predetermined preset time to output, to a control unit, a preset time elapse signal indicating this fact. At this time, the preset count value is compared with the count value of the pulse signal counted by the counting section. If the both are coincident with each other, a coincidence signal indicating this fact is outputted to the control unit. Accordingly, it is possible for the control unit to detect the stop of the cylinder and detect the displacement position of the piston rod at this time.

Claims8

Dependent claims

A counter for counting a number of pulses of a pulse signal outputted from an encoder, comparing said number of pulses with a preset count value, and outputting a coincidence signal if said number is substantially coincident with said preset count value, said counter comprising:

a time-measuring section for measuring an elapsed time from said output of said pulse signal during a period until the next pulse signal is outputted;
and
a signal output section for comparing said elapsed time with a preset time and outputting a preset time elapse signal at a point of time at which said elapsed time arrives at said preset time.

Dependencies are inferred from the claim text.

Counter

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Counter

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Abstract

Claims8