DEVICE FOR DETECTING THE POSITION OF A MACHINE.

摘要

A device for detecting the absolute position of a moving part of a machine using a rotary encoder. The object is to detect any error that may develop in the content stored in the absolute position storage means. A register (4) stores the absolute position of when the power source circuit is closed and the present absolute position that is detected by a rotary encoder (2) based on the subsequent amount of movement. A counter (5) counts the quantity of shift from a position of generating a one-turn signal of the rotary encoder (2). When the moving part stops, a coincidence circuit (6) collates the present position stored in the register (4) with the counted content of the register (5), and generates an error signal when they are not in agreement. Therefore, the machine tool and the like are prevented from erroneously operating.