Safe PLC, sequence program creation support software and sequence program judgment method
AssigneeJtekt Corporation
InventorsYouji Yoshida, Satoshi Kato, Tsutomu Araki, Mitsushi Nishi
Life of this patent
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Abstract
Preparation supporting software for sequence programs in a safety PLC capable of rewriting sequence programs, wherein the preparation supporting software for sequence programs judges whether or not an output section corresponding to an object sequence program is of the configuration ensured to be safe, based on input device kind information, which stores first kind information indicative of safety ensured or second kind information indicative of safety not ensured in correspondence to each input device, and the object sequence program, and displays the result of the judgment distinguishably.
Claims6
A safety PLC capable of rewriting sequence programs, comprising:
- input means for inputting signals relating to the conductive states of a plurality of input devices;
- storage means for storing sequence programs each configured by combining arbitrary input devices selected from the inputted input devices in serial or parallel and for storing input device information which classifies each of the input devices as providing either first information indicative of safety ensured or second information indicative of safety not ensured;
- and
- arithmetic means for obtaining an arithmetic result based on a sequence program and signals relating to the conductive states of respective input devices;
- and
- output means for outputting the arithmetic result of the arithmetic means from an output section to control an output device,
- wherein the safety PLC judges whether or not the arithmetic result outputted to the output section is of a configuration ensured to be safe, based on stored rules for identifying the arithmetic result as safe or not safe, the stored rules considering the sequence program and the input device information and,
- when judging that the configuration is not ensured to be safe, the safety PLC sends an output to alerting means and controls an output device connected to the output section toward a safe side.
Preparation supporting software for sequence programs in a safety PLC capable of rewriting sequence programs, the PLC comprising:
- input means for inputting signals relating to the conductive states of a plurality of input devices;
- storage means for storing sequence programs each configured by combining arbitrary input devices selected from the inputted input devices in serial or parallel and for storing input device kind information which classifies each of the input devices as providing either first information indicative of safety ensured or second information indicative of safety not ensured;
- arithmetic means for obtaining an arithmetic result based on a sequence program and signals relating to the conductive states of respective input devices;
- and
- output means for outputting the arithmetic result of the arithmetic means from an output section to control an output device,
- wherein the preparation supporting software for sequence programs judges whether or not an output section corresponding to an object sequence program is of the configuration ensured to be safe, based on rules for identifying the arithmetic result as safe or not safe, the stored rules considering the input device information, and
- the object sequence program and distinguishably displays a result of the judgment.
Dependencies are inferred from the claim text.