Kabushiki Kaisha Toshiba

Yoshimori Obata

Makoto Toko

The invention is aimed at providing a programmable logic control system capable of executing a plurality of functions to realize high-speed data communication between itself and a control input/output unit without degrading the performance of the programmable logic control system, thereby significantly enhancing the performance and simplifying maintenance. To attain the aim, the programmable logic control system comprises a plurality of separate modules obtained by grouping the operating sections and the input/output sections of the controllers in the form of separate modules, and mounted on a back board. On the back board, there is also provided a control input/output unit connector. A signal is used for the control input/output unit connector connected parallel to the separate modules via the back board, so that communication can be performed, during use of a bus, between the separate modules and the control input/output unit.

Programmable logic control system

A multiple-input digital filter capable of filtering a plurality of digital input signals with a single filtering device first latches the input signals and then sequentially selects each of the digital input signals for output to a counter circuit. The counter circuit, which is preset by the previous count value for the corresponding digital input signal, counts up or down depending on the digital input signal. When the count value reaches its maximum, a decision value signal is set for the corresponding digital input signal until the count value for that digital input signal returns to the minimum value. The count values are stored in a shift register which supplies the count value corresponding to the digital input signal as a preset value to the counter. A second shift register stores the decision values corresponding to each of the digital input signals which are then latched for simultaneous output.

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Tokyo, Japan

Yoshimori Obata