| 摘要 |
PROBLEM TO BE SOLVED: To provide a safety input device for a controller including a self-diagnostic function capable of performing the parallel execution of safe control hardly affected by noise superposed on an input line connecting an input end of a sensor or the like and the input device, and self-diagnosis. SOLUTION: The safety input device includes: an input control part 7 controlling the sending of an input signal to an arithmetic device in synchronization with a control period set in the arithmetic device 11a; an output control part 1 instructing to output preset first self-diagnostic pattern data; a test pattern generation part 2 outputting the first self-diagnostic pattern data by a base band transmission system where the first self-diagnostic pattern data are encoded as a pulse train signal having a pulse width not larger than a preset pulse width; a composition input part 4 composing the pulse train signal and the input signal; an input interface part 3; a pattern reconfiguration part 5 decoding an output signal of the composition input part as second self-diagnostic pattern data; and a comparison part 6 comparing the first and second self-diagnostic pattern data to decide the presence/absence of a difference. COPYRIGHT: (C)2011,JPO&INPIT |
