Node processing system

• US 5,003,533 A
• Filed: 07/25/1989
• Issued: 03/26/1991
• Est. Priority Date: 07/25/1988
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Watanabe, Akira
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Ton, Dang
• Application Number:
  US07/385,241
• Time in Patent Office: 609 Days
• Field of Search: 370/85.5, 370/94.3, 370/85.15, 370/16, 370/89, 370/94.1, 370/85.4, 340/825.05
• US Class Current: 370/258
• CPC Class Codes: H04L 12/42 Loop networks

Abstract

In the maintenance of a ring-type local area network, the physical number, physical addresses and connection sequence of nodes in the network can be readily made known without need of any management by system control personnel. To this end, a frame which can be discriminated only by the immediately succeeding station is used, and own addresses are successively set in an information field of the frame to convey the status of physical connection to the succeeding stations.

Claims

1. In a ring-type local area network including a plurality of node stations disposed on a ring channel, a method for determining the configuration of said network comprising the steps of producing in a source node, an adjacent station frame capable of being discriminated only by the immediately succeeding station, sending out said adjacent station frame with the source node address and a node count variable set in an information field of said adjacent station frame, detecting and receiving said adjacent station frame in a destination node, producing a different adjacent station frame by additionally setting the destination node address after the source node address in said information field and by modifying the node count variable in said information field of said received adjacent station frame, sending out said different adjacent station frame, and determining an end of sequence by detecting the presence of the source node address as the first node address in the information field of a received adjacent station frame, said method permitting the number, physical addresses and connection sequence of nodes of the entire ring-type local area network to be known from the contents of a received adjacent station frame.

2. The method according to claim 1, wherein each of said nodes successively adds its own address to the information field of the received adjacent station frame.

3. The method according to claim 2, wherein the step of modifying the node count variable of said information field comprises each immediately succeeding node station incrementing the node count variable in said received adjacent station frame.

4. A method for determining the address and number of nodes in a ring-type local area network having a plurality of station nodes, each node station having an address among which information is transferred, in a transmission direction, by transmission of data packets consisting of a token and a frame, said method comprising the steps of:

(a) generating, in a node station, a frame recognizable only by an adjacent node station, along said transmission direction, said frame containing a node count field and a node address field;

(b) modifying said node count field of said frame;

(c) writing the address of said node station in said node address field;

(d) transmitting said frame over said ring-type local area network;

(e) receiving said frame in said second node station; and

(f) repeating steps (a) through (d) for each node station in said network.

5. The method of claim 4 wherein step (a) further comprises copying the node count field and node address field from a previously received frame.

6. The method of claim 5 wherein step (c) comprises appending the address of said node station after a node address, if any, in said previously received node address field.

7. The method of claim 5 wherein step (b) comprises incrementing the value of the node count field from a previously received frame.

8. The method of claim 5 wherein after each node station has received a frame from an adjacent node station the value of the node count field represents the number of node stations in the ring-type local area network.

9. The method of claim 5 wherein after each node station has received a frame from an adjacent node station the data contained in said node address field represents the node station addresses and sequential order along said transmission direction of all node stations in said network.