Safety controller and system using same

1. A plurality of safety controllers for providing a safety output to a target controlled system based on an input from an input device to thereby control operation of machine equipment, said safety controllers forming a safety circuit that supplies power to said machine equipment only when safety condition is maintained by said plurality of safety controllers, each of said safety controllers comprising:

a plurality of safety output parts for transmitting a solid-state output as said safety output;

a connection output part for transmitting a connection output to another safety controller;

a control part for controlling said safety output and said connection output according to a program based on the input from said input device;

a connection input part for receiving a connection output from another safety controller as a connection input; and

a setting part for setting to enable and disable the connection input from said connection input part;

wherein said control part controls said safety output and said connection output based on an input from said input device and connection input from said connection input part;

wherein said connection output is a solid-state output for logical connection;

wherein said control part controls said safety output and said connection output by carrying out logical calculations according to said program based on said input from said input device and said connection input from said connection input part; and

wherein said control part controls said safety output and said connection output by disabling said connecting input if said setting part sets for disablement.

2. The safety controllers of claim 1 wherein said control part controls output condition of said connection output according to said program in same way as the output condition of said safety output.

3. A plurality of safety controllers for providing a safety output to a target controlled system based on an input from an input device to thereby control operation of machine equipment, said safety controllers forming a safety circuit that supplies power to said machine equipment only when safety condition is maintained by said plurality of safety controllers, each of said safety controllers comprising:

a plurality of safety output parts for transmitting a solid-state output as said safety output;

a connection output part for transmitting a connection output to another safety controller;

a control part for carrying out input process, diagnostic process and output process according to a program, said control part judging condition of input from said input device in said input process, carrying out self-diagnosis in said diagnostic process and controlling said safety output and said connection output based on results of said input process and said diagnostic process;

a connection input part for receiving a connection output from another safety controller as a connection input; and

a setting part for setting to enable and disable the connection input from said connection input part;

wherein said control part judges conditions of input from said input device and of connection input from said connection input part in said input process, carries out self diagnosis in said diagnostic process and controls said safety output and said connection output based on results of said input process and said diagnostic process;

wherein said connection output is a solid-state output for logical connection and said control part determines output conditions of said safety output and said connection output by a logical calculation on the input from said input device and the connection input from said connection input part in said input process and controls in said output process according to result of said diagnostic process said safety output and said connection output in a safe condition determined by said input process if there is no abnormality and in a predetermined output condition if there is an abnormality; and

wherein said control part controls said safety output and said connection output by disabling said connecting input if said setting part sets for disablement.

4. The safety controllers of claim 3 , each of said safety controllers further comprising a setting part for setting to enable and disable the connection input from said connection input part, wherein said control part controls said safety output and said connection output by disabling said connecting input if said setting part sets for disablement.

5. The safety controllers of claim 1 wherein said plurality of safety output parts include an instantaneous output part for outputting safety instantaneous outputs and an off-delay output part for outputting safety off-delay outputs.

6. The safety controllers of claim 1 wherein said safety output and said connection output have different signal patterns.

7. The safety controllers of claim 1 , each of said safety controllers being connectable to an expansion unit that contains a plurality of electromagnetic relays and is adapted to output a relay output corresponding to said safety output.

8. The safety controllers of claim 1 wherein said control part comprises two CPUs.

9. The safety controllers of claim 1 wherein said setting part is provided such that said setting part cannot be operated when said safety controller is installed in a specified manner.

10. The safety controllers of claim 9 wherein said setting part is operable from a back surface of a case, said safety controller being installed in said specified manner by being attached over said back surface.

11. The safety controllers of claim 1 wherein said setting part comprises a first setting part adapted to set at least a part of items to be set by said setting part and a second setting part adapted to set the same part of said items, said control part having two CPUs consisting of a first CPU and a second CPU, outputs from said first and second setting parts being respectively transmitted to said first and second CPUs, each of said CPUs serving to compare the outputs from said first and second setting parts.

12. The safety controllers of claim 11 wherein said second setting part is visually observable when said safety controller is installed in a specified manner.

13. A system comprising a plurality of safety controllers for providing a safety output to a target controlled system based on an input from an input device to thereby control operation of machine equipment, said safety controllers forming a safety circuit that supplies power to said machine equipment only when safety condition is maintained by said plurality of safety controllers, each of said safety controllers comprising:

a plurality of safety output parts for transmitting a solid-state output as said safety output;

a connection output part for transmitting a connection output to another safety controller, said plurality of safety controllers being connected together through the connecting output parts;

a control part for controlling said safety output and said connection output according to a program based on the input from said input device;

a connection input part for receiving a connection output from another safety controller as a connection input; and

a setting part for setting to enable and disable the connection input from said connection input part;

wherein said control part controls said safety output and said connection output based on an input from said input device and connection input from said connection input part;

wherein said connection output is a solid-state output for logical connection;

wherein said control part controls said safety output and said connection output by carrying out logical calculations according to said program based on said input from said input device and said connection input from said connection input part; and

wherein said control part controls said safety output and said connection output by disabling said connecting input if said setting part sets for disablement.

14. The safety controllers of claim 10 wherein said setting part comprises a first setting part adapted to set at least a part of items to be set by said setting part and a second setting part adapted to set the same part of said items, said control part having two CPUs consisting of a first CPU and a second CPU, outputs from said first and second setting parts being respectively transmitted to said first and second CPUs, each of said CPUs serving to compare the outputs from said first and second setting parts; and

wherein said second setting part is visually observable when said safety controller is installed in said specified manner.

15. The safety controllers of claim 3 wherein said setting part is provided such that said setting part cannot be operated when said safety controller is installed in a specified manner; and

wherein said setting part is operable from a back surface of a case, said safety controller being installed in said specified manner by being attached over said back surface.

16. The safety controllers of claim 3 wherein said setting part comprises a first setting part adapted to set at least a part of items to be set by said setting part and a second setting part adapted to set the same part of said items, said control part having two CPUs consisting of a first CPU and a second CPU, outputs from said first and second setting parts being respectively transmitted to said first and second CPUs, each of said CPUs serving to compare the outputs from said first and second setting parts; and

wherein said second setting part is visually observable when said safety controller is installed in a specified manner.

17. The safety controllers of claim 16 wherein said setting part is provided such that said setting part cannot be operated when said safety controller is installed in said specified manner; and

wherein said setting part is operable from a back surface of a case, said safety controller being installed in said specified manner by being attached over said back surface.

18. The system of claim 13 wherein said setting part is provided such that said setting part cannot be operated when said safety controller is installed in a specified manner; and

wherein said setting part is operable from a back surface of a case, said safety controller being installed in said specified manner by being attached over said back surface.

19. The system of claim 13 wherein said setting part comprises a first setting part adapted to set at least a part of items to be set by said setting part and a second setting part adapted to set the same part of said items, said control part having two CPUs consisting of a first CPU and a second CPU, outputs from said first and second setting parts being respectively transmitted to said first and second CPUs, each of said CPUs serving to compare the outputs from said first and second setting parts; and

wherein said second setting part is visually observable when said safety controller is installed in a specified manner.

20. The system of claim 18 wherein said setting part is provided such that said setting part cannot be operated when said safety controller is installed in said specified manner; and

wherein said setting part is operable from a back surface of a case, said safety controller being installed in said specified manner by being attached over said back surface.