PURPOSE: To make it possible that diagnosis of abnormality of respective take-up units is performed on the side of a center by connecting plural constant-length control devices to a monitoring computer on the side of factory, and, at the same time connecting that computer to a host computer on the side of the center by means of a telephone line.

CONSTITUTION: In equipment wherein a number of automatic winders (W) are respectively provided in respective factories M1, M2, and constant-length control devices 20 go control respective take-up units 11 of the bases 22 of respective winders (W) are provided to respective winders (W), respective constant-length control devices 20 are respectively connected to monitoring computers 23 through lines 24, and monitoring computers 23 on the side of respective factories are connected to a host computer 28 on the side of a center of the center (C) of a winder maker, etc., through modems 26, telephone lines 27 and a modem 29, and, data of the take-up units 11 of respective winders (W) transmitted daily from respective factories M1, M2 are stored, and at the same time, diagnosis of abnormality of respective take-up units 11 is performed from these data.