Field bus system for controlling safety-critical processes

• US 20040010651A1
• Filed: 04/29/2003
• Published: 01/15/2004
• Est. Priority Date: 10/30/2000
• Status: Abandoned Application

• Current Assignee: PILZ GmbH & Company
• Original Assignee: PILZ GmbH & Company
• Inventors: Wiegert, Alexander
• Application Number:
  US10/426,430
• Publication Number:
  US 20040010651A1
• Time in Patent Office: Days
• US Class Current: 710/305
• CPC Class Codes: G05B 2219/31135 Fieldbus
• CPC Class Codes: G05B 2219/31174 Load, use different protocols, formats, emulators for different systems
• CPC Class Codes: H04L 12/40169 Flexible bus arrangements arrangements for maintenance or administration involving management of faults; events, alarms H04L41/06; automatic restoration of network faults H04L41/0654
• CPC Class Codes: H04L 2012/40208 characterized by the use of a particular bus standard
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

The present invention relates to a field bus system for controlling safety-critical processes. The system has an open channel transmission medium and a plurality of bus subscribers connected to the transmission medium. The bus subscribers are configured to transmit bus messages via the transmission medium in order to communicate with each other. The system further has a defined communication protocol which predetermines rules for the transmission and reception of bus messages. The communication protocol includes an individual system identifier which is connected at least to each bus message transmitted via the open communication channel.

Claims

1. A method of controlling safety-critical processes in an automated installation, the method comprising the steps of:

providing a field bus system comprising a transmission medium having an open communication channel, and comprising a plurality of bus subscribers connected to the transmission medium, with the bus subscribers being configured to transmit bus messages across the transmission medium for communicating with each other thereby monitoring and controlling the safety-critical processes, and

providing a defined communication protocol which predetermines rules for the transmission and reception of the bus messages across the transmission medium,

wherein the communication protocol includes a system identifier individually set to identify the field bus system and distinguish it as an entity uniquely from other field bus systems of the same type, and

wherein the system identifier is combined with each bus message transmitted across the open communication channel.

2. The method of claim 1, wherein the system identifier is selected to be the same for all bus messages transmitted in the field bus system.

3. The method of claim 1, wherein the bus subscribers monitor emergency-stop switches, two-handed controllers, guard doors and/or light barriers for controlling the automated installation.

4. The method of claim 1, wherein the individual system identifier is intrinsically redundant.

5. The method of claim 1, wherein the individual system identifier includes a defined frequency signal which is transmitted with the bus messages across the open communication channel.

6. The method of claim 1, wherein the individual system identifier includes a data value which is transmitted as a part of the bus messages.

7. The method of claim 6, wherein the data value is autonomously protected against data errors.

8. The method of claim 1, wherein the transmission medium further comprises a closed communication channel and a signal converter connecting the closed communication channel and the open communication channel.

9. The method of claim 8, wherein the signal converter comprises a first safety stage which connects the system identifier to any bus message to be transmitted across the open communication channel.

10. The method of claim 8, wherein the signal converter comprises a second safety stage which checks the system identifier of any bus message received across the open communication channel.

11. The method of claim 8, wherein the signal converter comprises a filter stage which selects any bus messages to be transmitted across the open communication channel, while it suppresses any bus messages not to be transmitted across the open communication channel.

12. The method of claim 8, wherein the signal converter comprises an interchangeable storage medium on which the system identifier is stored in a non-volatile manner.

13. The method of claim 1, wherein each bus subscriber comprises an interchangeable storage medium on which the system identifier is stored in a non-volatile manner.

14. The method of claim 13, wherein the interchangeable storage medium further comprises an individual subscriber address also stored in a non-volatile manner.

15. The method of claim 1, wherein the open communication channel is a radio channel.

16. The method of claim 1, wherein the open communication channel is an Ethernet link.

17. A field bus system for controlling safety-critical processes in an automated installation, the system comprising a transmission medium and a plurality of bus subscribers which are connected to the transmission medium, with the bus subscribers being configured to transmit bus messages across the transmission medium for communicating with each other, the system further comprising a defined communication protocol, which sets rules for the transmission and reception of the bus messages, wherein the transmission medium comprises an open communication channel, and the communication protocol includes an individual system identifier which is combined with each bus message transmitted across the open communication channel.

18. The field bus system of claim 17, wherein the individual system identifier is intrinsically redundant.

19. The field bus system of claim 17, wherein the individual system identifier includes a defined frequency signal, which is transmitted with the bus messages across the open communication channel.

20. The field bus system of claim 17, wherein the individual system identifier includes a data value which is transmitted as a component of the bus messages.

21. The field bus system of claim 20, wherein the data value is autonomously protected against data errors.

22. The field bus system of claim 17, wherein the transmission medium further comprises a closed communication channel and a signal converter for connecting the closed communication channel to the open communication channel.

23. The field bus system of claim 22, wherein the signal converter comprises a first safety stage which combines any bus message to be transmitted across the open communication channel with the system identifier.

24. The field bus system of claim 22, wherein the signal converter comprises a second safety stage which checks the system identifier of any bus message received across the open communication channel.

25. The field bus system of claim 22, wherein the signal converter comprises a filter stage which selects any bus messages to be transmitted across the open communication channel, while it suppresses any bus messages not to be transmitted across the open communication channel.

26. The field bus system of claim 22, wherein the signal converter has an interchangeable storage medium on which the system identifier is stored in a non-volatile manner.

27. The field bus system of claim 17, wherein each bus subscriber has an interchangeable storage medium on which the system identifier is stored in a non-volatile manner.

28. The field bus system of claim 27, wherein the interchangeable storage medium further comprises an individual subscriber address also stored in a non-volatile manner.

29. The field bus system of claim 17, wherein the open communication channel is a radio channel.

30. The field bus system of claim 17, wherein the open communication channel is an Ethernet link.

31. A bus connection module for use in a field bus system for controlling safety-critical processes, the module comprising an interface for connecting a bus subscriber to a transmission medium and comprising a communication unit in which a communication protocol is implemented, wherein the interface is an open communication interface, and wherein the implemented communication protocol includes a system identifier configured to be individually set, which system identifier identifies the field bus system as an entity uniquely from other field bus systems of the same type, said interface being configured to combine the system identifier to any bus message to be transmitted.

32. The bus connection module of claim 31, further comprising an interface for an interchangeable storage medium in which the individual system identifier is stored in a nonvolatile manner.