MODBUS plus ethernet bridge

• US 6,434,157 B1
• Filed: 10/06/1998
• Issued: 08/13/2002
• Est. Priority Date: 10/06/1998
• Status: Expired due to Term

• Current Assignee: Schneider Automation Incorporated (Schneider Electric SE)
• Original Assignee: Schneider Automation Incorporated (Schneider Electric SE)
• Inventors: Davies, Cynthia, Dubeʼ, Denis W., Swales, Andrew G.
• Primary Examiner(s): Marcelo, Melvin
• Assistant Examiner(s): ABELSON, RONALD B
• Application Number:
  US09/167,251
• Time in Patent Office: 1,407 Days
• Field of Search: 370/401-405
• US Class Current: 370/401
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone

Abstract

A bridge is disclosed for providing a connection between a MODBUS Plus network and an Ethernet network. The bridge includes a MODBUS circuit board, an Ethernet circuit board, and a CPU. The MODBUS circuit board is operably coupled to the local area network for receiving a message from an originating node having a five-byte routing path field. The CPU is operably connected to the circuit board for extracting a table location in response to a third byte within the routing path field. The Ethernet circuit board is operably connected to the CPU and the Ethernet network for forwarding the message to an IP destination in response to the table location.

Claims

1. A bridge for providing a connection between a local area network and an Ethernet network comprising:

a local area network circuit board operably coupled to the local area network for receiving a message from an originating node having a routing path field;

a CPU operably connected to the circuit board for extracting a table location in response to the routing path field; and

,

an Ethernet circuit board operably connected to the CPU and the Ethernet network for forwarding the message to an IP destination in response to the table wherein the Ethernet circuit board receives a message from the Ethernet network, the message having an IP address and an embedded destination index byte, and the local area network board delivering the message received from the Ethernet network to a destination node on the local area network in response to the destination index byte.

2. The bridge of claim 1, wherein the CPU provides for mapping the embedded destination index byte to correspond with the destination node.

3. The bridge of claim 1, wherein the Ethernet circuit board is operably connected to another bridge for receiving the message and delivering the message to a destination node in response the routing path field.

4. The bridge of claim 1, wherein the CPU maintains at least two internal mapping tables between IP addresses and addresses of the local area network.

5. The bridge of claim 4, wherein a keyboard is operably connected to the CPU for configuring the mapping tables from a local keyboard.

6. The bridge of claim 4, wherein the CPU downloads the mapping tables from an Ethernet host.

7. A method for providing a connection between a local area network and an Ethernet network comprising the steps of:

receiving a message from an originating node on the local area network having a five-byte routing path field;

opening a path between the local area network and the Ethernet network in response to a second byte within the routing path field;

extracting a table location in response to the second byte within the routing path field;

forwarding the message to an IP destination on the Ethernet network in response to the table location and a one byte destination identification within a header transmitted on the Ethernet network;

receiving another message from the Ethernet network, the message having an IP address and an embedded destination index byte; and

delivering the message received from the Ethernet network to a destination node on the local area network in response to the destination index byte.

8. The method of claim 7, further including the step of mapping the embedded destination index byte to correspond with the destination node.

9. The method of claim 7, further including the steps of receiving the message from the Ethernet network and delivering the message to a destination node in response to a fourth byte within the routing path field.

10. The method of claim 7, further including the step of loading a program onto a personal computer for extracting the table location in response to the second byte within the routing path field.

11. The method of claim 7, further including the step of maintaining at least two internal mapping tables between IP addresses and addresses of the local area network.

12. The method of claim 11, further including the step of configuring the mapping tables from a local keyboard.

13. The method of claim 12, further including the step of downloading the mapping tables from an Ethernet host.

14. The method of claim 7, further including the step of closing the path between the local area network and the Ethernet network.

15. A method for providing a connection between a local area network and an Ethernet network comprising the steps of:

receiving a message from a originating node on the local area network having a five-byte routing path field;

opening a path between the local area network and the Ethernet network in response to a second byte within the routing path field;

extracting a table location in response to a second byte within the routing path field;

forwarding the message to an IP destination on the Ethernet network in response to the table location; and

receiving another message from the Ethernet network, the message having an IP address and an embedded destination index byte, and delivering the message received from the Ethernet network to a destination node on the local area network in response to the destination index byte.

18. The method of claim 15, further including the step of loading a program onto a personal computer for extracting the table location in response to the second byte within the routing path field.

16. A method for providing a connection between a local area network and an Ethernet network comprising the steps of:

receiving a message from a originating node on the local area network having a five-byte routing path field;

opening a path between the local area network and the Ethernet network in response to a second byte within the routing path field;

extracting a table location in response to a second byte within the routing path field;

forwarding the message to an IP destination on the Ethernet network in response to the table location; and

,

mapping the embedded destination index byte to correspond with the destination node.

17. A method for providing a connection between a local area network and an Ethernet network comprising the steps of:

receiving a message from a originating node on the local area network having a five-byte routing path field;

opening a path between the local area network and the Ethernet network in response to a second byte within the routing path field;

extracting a table location in response to a second byte within the routing path field;

forwarding the message to an IP destination on the Ethernet network in response to the table location; and

,

receiving the message from the Ethernet network and delivering the message to a destination node in response to a fourth byte within the routing path field.

19. The method of claim 17, further including the step of maintaining at least two internal mapping tables between IP addresses and addresses of the local area network.

20. The method of claim 19, further including the step of configuring the mapping tables from a local keyboard.

21. The method of claim 19, further including the step of downloading the mapping tables from an Ethernet host.

22. A bridge for providing a connection between a MODBUS Plus network and an Ethernet network comprising:

a MODBUS Plus circuit board operably coupled to the MODBUS Plus network for receiving a message from an originating node;

a CPU operably connected to the MODBUS circuit board for extracting a table location in response to the routing path field; and

,

an Ethernet circuit board operably connected to the CPU and the Ethernet network for forwarding the message to an IP destination in response to the table location wherein the routing path field has five bytes, and the CPU extracts the table location in response to a third byte with the routing path field, the third byte having an address range of from 1 to 255.

24. A dynamically configurable bridge operably connected between an Ethernet network host and a local area network, the bridge comprising:

a configuration destination index; and

, an application responsive to a message received at the configuration destination index from the host; and

,

a dynamic destination index utilized by the application for configuring the bridge for dynamic routing.

23. The bridge of claim 25, wherein the Ethernet circuit board is operably connected to another bridge for receiving the message and delivering the message to a destination node in response to a fourth byte within the routing path field.

25. The bridge of claim 24 further comprising the dynamic routing being host-based wherein the bridge can be configured by the host for simple addressing to the local area network.

26. The bridge of claim 24 further comprising the dynamic routing being socket-based wherein the bridge is capable of handling concurrent sessions from one or more hosts utilizing independent routing assignments.