Method and device for establishing the network topology of a bus system

• US 20040098514A1
• Filed: 03/28/2003
• Published: 05/20/2004
• Est. Priority Date: 09/29/2000
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Schuster, Armin
• Granted Patent: US 7,076,694 B2
• Time in Patent Office: Days
• US Class Current: 709/253
• 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 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

To determine the network topology of a bus system having a number of bus users positioned on bus segments of a bus line interconnected by at least one diagnosis repeater, an initiating measuring telegram is first sent to each bus user. This telegram is answered by the diagnosis repeater with a data telegram having a segment code and by other bus users with a response telegram. The diagnosis repeater then sends a measuring signal to each responding bus user, which reflects the signal. The distance of the responding bus user from the diagnosis repeater is determined from the time interval between the sending of the measuring signal and the arrival of the reflection signal.

Claims

1. A method for determining the network topology of a bus system (1) having a number of bus subscribers (T_n), which are arranged on mutually connected bus segments (B_n) of a bus line (2),

with each bus subscriber (T_n) being sent an initiating measurement message (SRD) which is responded to by a diagnosis repeater (3), which is provided with a measurement device (4) for reflection measurement and connects a number of bus segments (B_n), with a data message (DT) which has a segment identifier (SK), and is responded to by the other bus subscribers (T_n) with a response message (AS, RS),

with the diagnosis repeater (3) sending a measurement signal (MS) to the responding bus subscriber (T_n) which reflects this signal, and

with the distance (l_n) between the responding bus subscriber (T_n) and the diagnosis repeater (3) being determined from the time interval between the transmission of the measurement signal (MS) and the arrival of the reflection signal (RS).

2. The method as claimed in claim 1, in which the diagnosis repeater (3) increments a cascading identifier (KK) of a received data message (DT) and passes this on on a segment-specific basis.

3. The method as claimed in claim 1 or 2, in which the distance (l_n) to the responding bus subscriber (T_n) is stored in a topology table (7, 7′

) which is associated with the diagnosis repeater (3).

4. The method as claimed in claim 3, in which a segment identifier (BF) for the responding bus subscriber (T_n) is entered in the topology table (7, 7′

).

5. The method as claimed in claim 3 or 4, in which a status identifier (SF) for the responding bus subscriber (T_n) is entered in the topology table (7, 7′

).

6. The method as claimed in one of claims 3 to 5, in which the fault location of a line fault (F), which is detected by means of the measurement device (4), between two bus subscribers (T_n) is determined using the topology table (7).

7. An apparatus for determining the network topology of a bus system (1) having a number of bus subscribers (T_n) which are arranged on bus segments (B_n) of a bus line (2),

having a number of diagnosis repeaters (3) which connect the bus segments (B_n) to one another, and each of which has a segment-specific measurement device (4) for reflection measurement, and

having a measurement initiator (6), which is connected to the bus line (2) and sends a measurement message (SRD) to the bus subscribers (T_n), to which the or each diagnosis repeater (3) responds with a data message (DT) which has a segment identifier (SK), and every other bus subscriber (T_n) responds with a response message (RS),

with the diagnosis repeater (3) identifying a responding bus subscriber (T_n) and sending a measurement signal (MS) to it, and determining the distance to the responding bus subscriber (T_n) from the time interval between the transmission of the measurement signal (MS) and the arrival of a reflection signal (RS).

8. The apparatus as claimed in claim 7, in which each diagnosis repeater (3) has a topology table (7, 7′

), in which the distance (l_n) to the or to each bus subscriber (T_n) is entered, and which is identified by this associated bus segment (B_n).

9. The apparatus as claimed in claim 8, in which one or more of the following fields is associated with the addressed bus subscribers (T_n) in the topology table (7′

) of each diagnosis repeater (2);

a status field (SF) for indicating the identification of the bus subscriber (T_n),

a subscriber-specific bus segment field (BF_T) for association of a bus segment (B_n) which is connected to the diagnosis repeater (3),

a distance field (EF) for entering the distance (l_n) to the bus subscriber (T_n),

a type field (TF) for identifying the type of bus subscriber (T_n), and

a repeater-specific bus segment field (BF_R) for identifying a diagnosis repeater (3) which is adjacent on a segment-specific basis.

10. The apparatus as claimed in one of claims 7 to 9, in which each diagnosis repeater (3) has two measurement devices (4) for reflection measurement, with each bus segment (B_n) having only one associated measurement device (4) and with at least one measurement initiator (6) being arranged on at least one bus segment (B_n).