PURPOSE: To enable to stop a troubled robot while continuing operations of robots except the troubled robot and indicate abnormals after the workings therefore are finished, in case a plurality of robots are being operated.

CONSTITUTION: In a system in which a plurality of mechanism portions 1 are driven by commands from a central processing unit (CUP) 2, present values of the mechanism portions 1 are detected by position detectors 3 and signals are sent to servo systems 8, and thus, the mechanism portions 1 are controlled. When some abnormals are caused within the mechanism portion 1, CUP 2 detects the caused abnormals by status signals and sends signals, regarding to a device and a number of robot in which the abnormals are caused, to be memorized in a read and memorizing device (RAM) 20 capable of reading and recording as well as temporal memorizing. During this period, robots without troubles are continued to operate, and after all works for the all robots are finished, CPU 2 indicates the number of the troubled robot by an indicating lamp 22 in accordance with the data of the RAM 20.