The programmable controller ( PC in short ) is operated by the instruction input from the pushbutton switch, digital switch, etc. provided on the operation panel, or sensor input from the limit switch, proximity switch, photo-electric switch, etc. used to detect the operation condition of the equipment, and serves to control the driving loads such as solenoid valve, motor, electromagnetic clutch, etc. and indication load such as pilot lamp, digital indicator, etc.
The transmission of output signal against these input signals is determined by the content of program to be provided to the programmable controller.
The light loads such as small type solenoid valve, pilot valve, etc. can be directly driven by the programmable controller, however, the heavy loads such as 3 phase motor, large capacity solenoid valve, etc. need to be driven through the contactor or the intermediate relay.
Such contactor, intermediate relay, power breaker, etc. are installed in the control panel together with the programmable controller.
The programmable controller will play the important roles as a small type, high-reliability and flexible brain when designing the automated product machining, assembling, transfer, inspection, packing, etc.
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