Title:
POWER SUPPLY DISCONNECTION DETECTOR IN SEQUENCE CONTROLLER
Document Type and Number:
Japanese Patent JPH01114901
Kind Code:
A
Abstract:
PURPOSE:To prevent an IC element constituting a module from being destructed by providing the title detector with means for detecting the complete stop and instantaneous stop of power supply to an I/O module and inhibiting the I/O operation of a programmable controller by an abnormality deciding means. CONSTITUTION:When a power supply VCC arranged on the side of the I/O module the I/O module 20 is completely stopped, current flows from a power supply VCC arranged on the side of the programmable controller 10 to the earth through a resistor R1, a signal line 31, a diode D1, and a resistor R2 and the electric potential of a comparator 16 is dropped only by a voltage drop due to the resistor R1. The comparator 16 detects the potential drop of a terminal A based on comparison with a reference voltage, outputs an abnormality signal and inputs the signal to an interruption terminal of a central processing unit (CPU) 12. When the power supply VCC is instantaneously stopped or reduced, a signal is outputted from an instantaneous detecting circuit 23 and current is similarly allowed to flow into the earth, and an abnormality signal is generated from the comparator to stop the operation of the CPU 12.
Inventors:
NIWA KUNIYUKI
FUJIMURA SUKEYUKI
FUJIMURA SUKEYUKI
Application Number:
JP27277587A
Publication Date:
May 08, 1989
Filing Date:
October 28, 1987
Export Citation:
Assignee:
TOYODA MACHINE WORKS LTD
International Classes:
G05B9/02; G05B19/04; G05B19/048; G05B19/05; (IPC1-7): G05B9/02; G05B19/04
Attorney, Agent or Firm:
Yusaku Goto