Input device of safety unit

• US 20060271833A1
• Filed: 04/18/2006
• Published: 11/30/2006
• Est. Priority Date: 04/19/2005
• Status: Active Grant

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Teranishi, Keiichi, Hioka, Takehiko, Ikeno, Naoaki, Muneta, Yasuo, Fujiwara, Shohei, Yoshida, Katsufumi, Koshiro, Chiaki, Suganuma, Hiromu, Nakamura, Toshiyuki, Matsui, Asahi
• Granted Patent: US 7,555,353 B2
• Time in Patent Office: Days
• US Class Current: 714/799
• CPC Class Codes: G05B 19/0425 Safety, monitoring
• CPC Class Codes: G05B 19/058 Safety, monitoring
• CPC Class Codes: G05B 2219/14012 Safety integrity level, safety integrated systems, SIL, SIS
• CPC Class Codes: G05B 2219/14075 Test of interface
• CPC Class Codes: G05B 2219/14076 Test of sensor

Abstract

This invention provides an input device of safety unit which enables an error diagnosis result referred to in a process of input processing for generating a control data from raw input signal to be referred by a side using the control data also in a safety unit such as a safety master and safety slave. An input device contains a function of outputting status data indicating the error diagnosis result referred to when input signal is converted to control data and the control data obtained by the conversion in pair, so that when the logical value of the control data is “LOW”, whether it originates from that the raw logical value is “LOW” or that “LOW” is compulsorily set due to an error in the terminal can be determined from the logical value of the status data.

Claims

1. A safety slave unit that with an input device based on a safety specification and activated when a danger exists connected thereto, receives a signal about presence or absence of action from the input device as an input, is connected to a safety controller based on the safety specification through a network so as to transmit the input signal to a communication master of the safety controller, comprising:

an input terminal portion having one or more input terminals supplied with an input signal from the input device based on the safety specification;

an error diagnostic portion that fetches information of a self-diagnosis result of the input device connected to each input terminal of the input terminal portion individually; and

a processing device that handles an error diagnosis result of the error diagnostic portion as a status data, regards a raw logical value about presence or absence of action of the input device, which is an input signal given to the input terminal portion, as indicating presence of action compulsorily when the error diagnosis result is presence of an error, while when the error diagnosis result is normal, maintains the raw logical value, and handles the raw logical value as a control data and transmits the control data and the status data in pair to the communication master of the safety controller.

2. A control system in which a safety controller based on a safety specification having a communication master portion and a safety slave unit for a safety application are connected through a network, wherein

the safety slave unit comprises:

an input terminal portion that has an input terminal and to which an input device based on the safety specification is connected through the input terminal and receives a signal about presence or absence of action from the input device as an input;

an error diagnostic portion that fetches information of a self-diagnosis result of each input device connected to each input terminal individually; and

a processing device that handles an error diagnosis result of the error diagnostic portion as a status data, regards a raw logical value about presence or absence of action of the input device, which is an input signal given to the input terminal portion, as indicating presence of action compulsorily when the error diagnosis result is presence of an error, while when the error diagnosis result is normal, maintains the raw logical value, and handles the raw logical value as a control data and transmits the control data and the status data in pair to the communication master of the safety controller, and wherein

the safety controller receives a pair data of the control data and the status data from the safety slave through the communication master portion and when the received control data indicates a status about presence of an action, determines whether the status originates from that a logical value indicates presence of the action or the presence of the action is compulsorily induced due to the error diagnosis result, based on the logical values of the control data and the status data.

3. A safety controller that with an input device based on a safety specification and activated when a danger exists, receives a signal about presence or absence of an action as an input, connects an input unit that handles the signal as an input signal through an internal bus, while the CPU unit inputs an input signal of the input unit, and executes safety logic control based on the input signal, wherein the input unit includes:

an input terminal portion having one or more input terminals supplied with an input signal from the input device based on the safety specification;

an error diagnostic portion that fetches information of a self-diagnosis result of the input device connected to each input terminal of the input terminal portion individually; and

a processing device that handles an error diagnosis result of the error diagnostic portion as a status data, regards a logical value about presence or absence of the action of the input device, which is an input signal given to the input terminal portion, as presence of the action compulsorily when the result of error diagnosis is presence of an error, while when the result of the error diagnosis is normal, maintains the logical value about the presence or absence of the action, handles the logical value as the control data and transmits the control data and status data in pair to the CPU unit through the internal bus and

the CPU unit includes a central processing portion that with a pair data of the control data and the status data inputted from the input unit, when the inputted control data indicates a status about presence of the action, determines whether status originates from that the raw logical value indicates presence of the action or the presence of the action is compulsorily induced due to the error, based on the logical values of the control data and status data.

4. An input device of a safety unit comprising:

an input terminal portion having one or more input terminals supplied with an input signal from an input device based on a safety specification;

an error diagnostic portion used for diagnosing presence or absence of an error in each input terminal of the input terminal portion;

an error diagnosing device for diagnosing presence or absence of the error in each input terminal of the input terminal portion using the error diagnosing portion; and

an input device that converts an input signal having a raw logical value given to each input terminal of the input terminal portion to a control data having a logical value whose safety is guaranteed by reference to a result of error diagnosis with the error diagnosing device,

wherein

the input device contains a function that outputs a status data indicating the error diagnosis result referred to when the input data is converted to the control data and the control data obtained by that conversion in pair, so that when the logical value of the control data is “

LOW”

, whether it originates from that the raw logical value is “

LOW”

or that “

LOW”

is compulsorily set due to an error is capable of being determined from a logical value of the status data making a pair with the control data.

5. The input device of safety unit according to claim 4 wherein the logical value of the status data is “

LOW”

when an error exists and “

HIGH”

when no error exists.

6. The input device of safety unit according to claim 5 wherein while the input device reflects a raw logical value given to the input terminal on the control data as it is when the result of error diagnosis indicates absence of an error, the input device sets the logical value of the control data to “

LOW”

compulsorily regardless of the raw logical value given to the input terminal when the result indicates presence of the error.

7. A safety slave unit comprising:

an input terminal portion having one or more input terminals supplied with an input signal from an input device based on a safety specification;

an error diagnostic portion used for diagnosing presence or absence of an error in each input terminal of the input terminal portion;

an error diagnosing device for diagnosing presence or absence of the error in each input terminal of the input terminal portion using the error diagnosing portion; and

an input device that converts an input signal having a raw logical value given to each input terminal of the input terminal portion to a control data having a logical value whose safety is guaranteed by reference to a result of error diagnosis with the error diagnosing device, and outputs the control data with a status data indicating the error diagnosis result in pair; and

a transmitting device for transmitting the control data obtained by the input device with the status data in pair to the network,

wherein

a receiving side of the transmission through the network has a function of determining whether, when the logical value of the received control data is “

LOW”

, it originates from that the raw logical value is “

LOW”

or that “

LOW”

is compulsorily set due to an error in the terminal from a logical value of the status data being in pair with the control data.

8. The safety slave unit according to claim 7 wherein the logical value of the status data is “

LOW”

when an error exists and “

HIGH”

when no error exists.

9. The safety slave unit according to claim 8 wherein while the input device reflects a raw logical value given to the input terminal on the control data as it is when the result of error diagnosis indicates absence of error, the input device sets the logical value of the control data to “

LOW”

compulsorily regardless of the raw logical value given to the input terminal when the result indicates presence of the error.

10. A safety controller comprising:

an input terminal portion having one or more input terminals supplied with an input signal from an input device based on a safety specification;

an error diagnostic portion used for diagnosing presence or absence of an error in each input terminal of the input terminal portion;

an error diagnosing device for diagnosing presence or absence of the error in each input terminal of the input terminal portion using the error diagnosing portion; and

an input device that converts an input signal having a raw logical value given to each input terminal of the input terminal portion to a control data having a logical value whose safety is guaranteed by reference to a result of error diagnosis with the error diagnosing device, and outputs the control data with a status data indicating the error diagnosis result in pair; and

a transmitting device for transmitting the control data obtained by the input device with the status data being in pair to the network,

wherein

a receiving side of the transmission through the network has a function of determining whether, when the logical value of the received control data is “

LOW”

, it originates from that the raw logical value is “

LOW”

or that “

LOW”

is compulsorily set due to an error in the terminal from a logical value of the status data being in pair with the control data.

11. The safety controller according to claim 10 wherein the logical value of the status data is “

LOW”

when an error exists and “

HIGH”

when no error exists.

12. The safety controller according to claim 11 wherein while the input device reflects a raw logical value given to the input terminal on the control data as it is when the result of error diagnosis indicates absence of error, the input device sets the logical value of the control data to “

LOW”

compulsorily regardless of the raw logical value given to the input terminal when the result indicates presence of the error.

13. A safety control system in which a safety controller functioning as a safety master and a remote safety unit functioning as a safety slave are connected through a network, wherein the remote safety unit comprising:

an input terminal portion having one or more input terminals supplied with an input signal from an input device based on a safety specification;

an error diagnostic portion used for diagnosing presence or absence of an error in each input terminal of the input terminal portion;

an error diagnosing device for diagnosing presence or absence of the error in each input terminal of the input terminal portion using the error diagnosing portion;

an input device that converts an input signal having a raw logical value given to each input terminal of the input terminal portion to a control data having a logical value whose safety is guaranteed by reference to a result of error diagnosis with the error diagnosing device, and outputs the control data with a status data indicating the error diagnosis result in pair; and

a transmitting device for transmitting the control data obtained from the input device with the status data in pair to the network,

and wherein the safety controller includes;

a receiving device for receiving the control data and the status data in pair from network; and

an input data reproducing device for reproducing input data based on the control data and the status data in pair.

14. The safety control system according to claim 13 wherein the logical value of the status data is “

LOW”

when an error exists and “

HIGH”

when no error exists.

15. The safety control system according to claim 14 wherein while the input device reflects a raw logical value given to the input terminal on the control data as it is when the result of error diagnosis indicates absence of error, the input device sets the logical value of the control data to “

LOW”

compulsorily regardless of the raw logical value given to the input terminal when the result indicates presence of the error.