Cable assembly for providing a data acquisition system with data messages passing on a fieldbus of rolling stock

Abstract

A cable assembly for providing a data acquisition system with data messages passing on a fieldbus of rolling stock, said cable assembly comprising a data listener adapted to listen in on said data messages passing on said fieldbus; a data transmitter adapted to transmit said data messages to said data acquisition system; and an isolation module adapted to electrically isolate said data transmitter from said data listener and from said fieldbus, thereby electrically isolating said data acquisition system from said fieldbus such that said data acquisition system is limited by said isolation module to only listening in on said data messages passing on said fieldbus.

Claims

1. A cable assembly for providing a data acquisition system with data messages passing on a fieldbus of rolling stock, said cable assembly comprising: a data listener adapted to listen in on said data messages passing on said fieldbus; a data transmitter adapted to transmit said data messages to said data acquisition system; and an isolation module adapted to electrically isolate said data transmitter from said data listener and from said fieldbus, thereby electrically isolating said data acquisition system from said fieldbus such that said data acquisition system is limited by said isolation module to only listening in on said data messages passing on said fieldbus; wherein: said fieldbus comprises two data message lines, both data message lines being adapted to carry a redundant differential signal; said data listener only listens in on said redundant differential signal only from one of said data message lines; and said data listener is further adapted to convert said redundant differential signal into a TTL signal and to send said TTL signal to said isolation module which is adapted to transmit said TTL signal to said data transmitter.

2. The cable assembly according to claim 1, wherein said isolation module is further adapted to electrically isolate said data transmitter from said data listener and from said fieldbus such that said isolation module prevents said data transmitter from transmitting messages to said fieldbus, thereby preventing said data acquisition system from transmitting messages to said fieldbus.

3. The cable assembly according to claim 1, wherein said fieldbus is a Multifunction Vehicle Bus and/or a vehicle fieldbus comprising one of the following protocols: Factory Instrumentation Protocol or FIP or WorldFIP; Profibus; Profinet; LonWorks; Controller Area Network or CANopen; SAE J1708; SAE J1939; MODBUS; Wire Train Bus or WTB.

4. The cable assembly according to claim 1, wherein isolation module is electrically interposed between said data listener and said data transmitter, thereby electrically isolating said data transmitter from said data listener and from said fieldbus.

5. The cable assembly according to claim 1, wherein said cable assembly is further adapted to covertly listen in on said data messages passing on said fieldbus, thereby allowing said data messages to pass on said fieldbus.

6. The cable assembly according to claim 1, wherein said data listener does not listen in on said redundant differential signal form the other data message line, such that said redundant differential signal on the other data message line of said fieldbus is not listened in by said cable assembly.

7. The cable assembly according to claim 1, wherein said data transmitter is further adapted to convert said TTL signal into a differential signal and to send said differential signal to said data acquisition system.

8. The cable assembly according to claim 1, wherein said isolation module is a galvanic isolation module.

9. The cable assembly according to claim 1, wherein said data transmitter comprises an input impedance larger than 50 kOhms.

10. The cable assembly according to claim 8, wherein said galvanic isolating module comprises a ground isolating unit, adapted to access a ground of said two data message lines; and wherein said data listener is further adapted to ground said redundant differential signal according to said ground.

11. The cable assembly according to claim 10, wherein said cable assembly further comprises a power input filter.

12. A method for providing a data acquisition system with data messages passing on a fieldbus of rolling stock, said method comprising the steps of: listening in on said data messages passing on said fieldbus by a data listener; transmitting said data messages to said data acquisition system; and electrically isolating said data acquisition system from said fieldbus such that said data acquisition system is limited by said isolation module to only listening in on said data messages passing on said fieldbus; wherein: said fieldbus comprises two data message lines, both data message lines being adapted to carry a redundant differential signal; said data listener only listens in on said redundant differential signal only from one of said data message lines; and said data listener is further adapted to convert said redundant differential signal into a TTL signal and to send said TTL signal to said isolation module which is adapted to transmit said TTL signal to said data transmitter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically illustrates an embodiment of a cable assembly according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENT(S)

(2) According to an embodiment shown in FIG. 1, a cable assembly 1 according to the present invention is coupled to a fieldbus 3 and positioned between a fieldbus device 30 coupled to the fieldbus 3 and a data acquisition system 2 of rolling stock 10. The fieldbus 3 is a Multifunction Vehicle Bus or a vehicle fielbus comprising FIP or Profibus or CAN or Profinet or LonWorks. The cable assembly comprises a data listener 101, a data transmitter 102 and an isolation module 103. The cable assembly 1 is coupled to the fieldbus device 30 via a connector 20. The connector 20 is for example a 9 pins D-Sub type of connector. According to an alternative embodiment, the connector 20 is a Deutsch HD10-9-96P type of connector. According to a further alternative embodiment, the connector 20 is a M12 type of connector. The data listener 101 listens in on data messages 300 passing on the fieldbus 3. The data listener 101 covertly listens in on the data messages 300 passing on the fieldbus 3, thereby allowing the data messages 300 to pass on the fieldbus 3 between the connector 20 and the connector 21 of the cable assembly 1. The connector 21 is for example a 9 pins D-Sub type of connector. According to an alternative embodiment, the connector 21 is a RJ-45 type of connector. According to a further alternative embodiment, the connector 21 is a Deutsch DT04-4P type of connector. The fieldbus comprises two data message lines 31;32, both data message lines 31;32 carrying a redundant differential signal 302. The data listener 101 is coupled to only one of the two data message lines 31;32, thereby listening in on the redundant differential signal 302 only from one of the two data message lines 31;32. The data listener 101 is not coupled to the other of the two data message lines 31;32. In other words, the redundant differential signal 302 on the other of the two data message lines 31;32 is not listened in by the cable assembly 1. The data listener 101 converts the redundant differential signal 302 into a TTL signal 303 and sends the TTL signal 303 to the isolation module 103. The isolation module 103 is electrically interposed between the data listener 101 and the data transmitter 102. The data listener 101 listens in only on the redundant differential signal 302 only from one of the two data message lines 31;32. The data listener 101 does not listen in on the other of the two data message lines 31;32. In other words, the redundant differential signal 302 on the other of the two data message lines 31;32 is not listened in by the cable assembly 1. The isolation module 103 electrically isolates the data listener 101 from the data transmitter 102 and sends the TTL signal 303 received from the data listener 101 to the data transmitter 102. The data transmitter 102 converts the TTL signal 303 in to a differential signal 304 and sends the differential signal 304 to the data acquisition system 2. The data transmitter 102 is coupled to the data acquisition system 2 via for example a high-speed data link 301. The high-speed data link 301 is for example a link adapted for speed transfers of 1.5M bits/second. According to an alternative embodiment, the high-speed data link 301 is for example a link adapted for speed transfers of 10M bits/second. According to an alternative embodiment, the data transmitter 102 is coupled to the data acquisition system 2 via 100 or 120 Ohms impedance controlled multi pair cable. The isolation module 103 comprises a galvanic isolation module. Optionally, the galvanic isolation module comprises a ground isolating unit 104 which accesses the ground 33 of the fieldbus 3. In other words, the ground isolating unit 104 accesses the ground 33 of the data message lines 31;32 and grounds the redundant differential signal 302 according to the ground 33, thereby electrically isolating the data transmitter 102 from the data listener 101. The cable assembly 1 further comprises a input filter 105. The power input filter 105 for example comprises a ferrite and capacitors. The power input filter 105 receives power 4 from the data acquisition system 2 and the power input filter 105 powers in return the data transmitter 102 and the isolation module 103 via power 4.

(3) Although the present invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied with various changes and modifications without departing from the scope thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. In other words, it is contemplated to cover any and all modifications, variations or equivalents that fall within the scope of the basic underlying principles and whose essential attributes are claimed in this patent application. It will furthermore be understood by the reader of this patent application that the words “comprising” or “comprise” do not exclude other elements or steps, that the words “a” or “an” do not exclude a plurality, and that a single element, such as a computer system, a processor, or another integrated unit may fulfil the functions of several means recited in the claims. Any reference signs in the claims shall not be construed as limiting the respective claims concerned. The terms “first”, “second”, third”, “a”, “b”, “c”, and the like, when used in the description or in the claims are introduced to distinguish between similar elements or steps and are not necessarily describing a sequential or chronological order. Similarly, the terms “top”, “bottom”, “over”, “under”, and the like are introduced for descriptive purposes and not necessarily to denote relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and embodiments of the invention are capable of operating according to the present invention in other sequences, or in orientations different from the one(s) described or illustrated above.