PURPOSE: To make it possible to measure the positioning accuracy of the drawing device automatically, by giving pseudo black and white sensing pulses to the drawing device which generates feedback pulse based on the movement, and counting the feedback pulse between the sensing pulses.
CONSTITUTION: A specified command is given to a control device of the drawing device having a moving means provided with a pulsed feedback function, and the pseudo black and white sensing pulses (a) is generated. The number of the feed-back pulses (b) between said sensing pulses are counted, and the positioning accuracy of the moving means itself is automatically measured. For example, the specified command is given to a control device 2 from a paper tape reader 4, and the pseudo black and white sensing pulses (a) are generated. A counter in a measuring function part 3 is reset via a control circuit 6 in the drawing device 1. Based on the command given to the control device, the drawing device is driven (c), and the feedback pulses (b) are generated. The difference between the command value and the acutual amount of the movement is obtained by counting, the result is displayed on a printer, and highly accurate automatic measuring is performed.
HAYASHI ITSUO
YAMADA YOSHIMI
