CONNECTION CONTROL SYSTEM

PURPOSE:To recover an input/output device from an abnormal condition without stopping a system as a whole by changing an ER control signal to the input/ output device from OFF to ON and initializing the input/output device from a personal computer side. CONSTITUTION:By assigning a resetting terminal to a terminal, which is not used at an input/output device 2 side on an RS-232-C interface, for example, 9 pins, a receiving part 6 is connected. To the receiving part 6, an ER signal, which is a transmission part 5 transmitting signal of a personal computer 1, is transmitted. A transmission part 5 of the personal computer 1 executes the ON/OFF control by the program. At the time of OFF, the signal is communicated to the receiving part 6 in the input/output device 2 through an interface cable 8, and a control part 4 of the input/output device 2 is kept in the resetting condition through a resetting signal line 7. When the signal is changed from OfF to ON, after the control part 4 is initialized, the operatable condition is obtained. Thus, without turning OFF/ON the power source of a personal computer system, the input/output device can be recovered from the abnormal condition.