Safety network system, safety slave, and safety controller

• US 7,120,505 B2
• Filed: 06/21/2002
• Issued: 10/10/2006
• Est. Priority Date: 06/22/2001
• Status: Expired due to Term

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Nakamura, Toshiyuki, Muneta, Yasuo
• Primary Examiner(s): PATEL, RAMESH B
• Application Number:
  US10/481,516
• Publication Number:
  US 20040215354A1
• Time in Patent Office: 1,572 Days
• Field of Search: 700/2, 700/3, 700/5, 700/21, 700/79, 700/80, 700/81, 700/82, 709/208, 709/209, 709/210, 709/211, 710/110
• US Class Current: 700/3
• CPC Class Codes: G05B 19/0428 Safety, monitoring G05B19/0423 takes precedence
• CPC Class Codes: G05B 19/058 Safety, monitoring
• CPC Class Codes: G05B 2219/14114 Integrity, error detector, switch off controller, fail safe
• CPC Class Codes: G05B 2219/15005 Set switches defining control function
• CPC Class Codes: G05B 2219/31131 Field device with gateway functions for communication with pc and other field devices
• CPC Class Codes: G05B 2219/31189 Time multiplex
• CPC Class Codes: G05B 2219/31211 Communicate diagnostic data from intelligent field device controller to central
• CPC Class Codes: G05B 2219/36159 Detachable or portable programming unit, display, pc, pda
• CPC Class Codes: G05B 9/02 electric
• CPC Class Codes: H04B 2203/5458 Monitor sensor; Alarm systems
• CPC Class Codes: H04B 3/542 the information being in digital form
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 2012/4026 Bus for use in automation systems
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A safety network system is constructed by connecting a safety PLC to a safety slave through a safety network. The safety slave obtains safety input informations from a plurality of safety devices connected thereto and transmits information based on the plurality of safety input informations in response to a request from the safety PLC. At this time, the safety slave determines whether or not a safety condition is satisfied based on the plurality of safety input informations, includes two notification modes, that is, a result notification mode in which a result of determination of safety determined by the above determination is transmitted and a detailed information mode in which the plurality of safety input informations are transmitted as they are as aggregated data, and returns a safety response in any of the modes according to a command from the safety PLC. In the result notification mode, the response can be returned at a high speed because an amount of data is small, and, in the detailed information mode, detailed information can be secured.

Claims

1. A safety slave configured for connection to a safety network and which transmits information based on a plurality of safety information inputs managed by the safety slave in response to a request from a safety controller sent through the safety network, comprising:

safety determination means for determining whether or not a safety condition is satisfied based on the plurality of safety information inputs; and

means for transmitting a result of a determination of safety determined by the safety determination means, as the information.

2. The safety slave according to claim 1, wherein information in the information inputs is composed of aggregated data, and wherein the safety slave is configured to use the plurality of safety information inputs without modification since the information is composed of aggregated data.

3. The safety slave according to claim 1, wherein the safety slave is configured to detect the cause of danger to at least one of the safety slave itself and devices managed by the safety slave as well as transmitting data indicative of the cause of danger detected thereby by adding it to the information.

4. The safety slave according to claim 1, wherein the safety slave is a safety gateway to which a different type of a field bus is connected.

5. The safety slave according to claim 4, wherein:

the safety information comprises a plurality of safety information inputs from a plurality of other safety slaves connected to the safety gateway; and

wherein;

the safety gateway is configured to transmit the plurality of safety information inputs obtained in each predetermined unit using time-sharing.

6. The safety slave according to claim 1, wherein the safety slave is configured to transmit at least in one of a result notification mode in which the result of determination of safety is transmitted, and a detailed information mode which is different from the result notification mode and in which more detailed information is transmitted, and

wherein switching of the transmission modes is selectively executed based on a communication command from the safety controller.

7. The safety slave according to claim 1, wherein:

the safety slave is configured to transmit at least in one of a result notification mode in which the result of determination of safety is transmitted and in a detailed information mode which is different from the result notification mode and in which more detailed information is transmitted; and

wherein;

the safety slave comprises a setting switch means for switching the modes in which transmission is executed.

8. A safety network system wherein a safety controller is connected to the safety slave according to claim 1, through a safety network, and wherein the information from the safety slave is transmitted to the safety controller through the safety network.

9. A safety controller connected to a safety network so as to comprises a safety network system having a safety slave according to claim 2, characterized in that:

the safety controller comprises a state storing unit for storing and holding whether or not the state of the safety network system is in a safe state,

wherein, when a present state stored in the state storing unit is safe, the safety controller requests the safety slave to transmit the result of the determination of safety; and

when the present state stored in the state storing unit is not safe, the safety controller requests the safety slave to transmit detailed information which is more detailed than the result of determination of safety.

10. A safety slave configured to be connected to a safety network and to transmit information based on a plurality of safety information inputs managed by the safety slave to other nodes connected to the safety network, comprising:

a safety determination means for determining whether or not a safety condition is satisfied based on the plurality of safety information inputs; and

means for transmitting a result of determination of safety determined by the safety determination means as the information.

11. A safety network system comprising a safety slave connected to a safety network, wherein information from the safety slave is transmitted to at least one other node through the safety network, and

wherein the safety slave is configured to be connected to the safety network and to transmit information, based on a plurality of safety information inputs managed by the safety slave, to the at least one other node connected to the safety network, and which comprises:

a safety determination means for determining whether or not a safety condition is satisfied based on the plurality of safety information inputs; and

means for transmitting a result of determination of safety determined by the safety determination means as the information.