Communication system and method for synchronization of the same

• US 20060083213A1
• Filed: 10/11/2005
• Published: 04/20/2006
• Est. Priority Date: 10/15/2004
• Status: Active Grant

• Current Assignee: Bosch Rexroth AG (Robert Bosch GmbH)
• Original Assignee: Bosch Rexroth AG (Robert Bosch GmbH)
• Inventors: Schultze, Stephan, Schmid, Thomas, Leurs, Ludwig, Kynast, Rigobert
• Granted Patent: US 8,170,066 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04J 3/0664 unidirectional timestamps
• CPC Class Codes: H04L 12/42 Loop networks
• CPC Class Codes: H04L 7/04 Speed or phase control by synchronisation signals H04L7/0075 takes precedence

Abstract

With a method for synchronization in a communication system that includes a central participant and at least one further participant, at least one of the further participants being synchronized with the central participant, and, to this end, a telegram with synchronization information being transmitted by the central participant to the at least one further participant, particularly efficient synchronization of the at least one participant with the central participant results due to the fact that the telegram is a data telegram.

Claims

1-32. -32. (canceled)

33. A method for synchronization in a communication system including a central participant in at least one further participant, comprising the steps of synchronizing the at least one further participant with the central participant by transmitting a telegram with synchronization information by the central participant to the at least one further participant;

and forming the telegram as a data telegram.

34. A method as defined in claim 33;

and further comprising forming the data telegram as a Master Data Telegram which includes setpoint values for process interfaces controlled by the at least one further participant.

35. A method as defined in claim 33;

and further comprising embedding the synchronization information in a data field of the data telegram.

36. A method as defined in claim 35;

and further comprising forming the synchronization information as a subfield of the data field.

37. A method as defined in claim 36;

and further comprising forming the subfield containing the synchronization information as a first entry in the data field.

38. A method as defined in claim 36;

and further comprising occurring an end of the subfield containing the synchronization information at a specified time interval after a beginning of the data telegram.

39. A method as defined in claim 38;

and further comprising using the specified time interval of substantially 2 μ

s.

40. A method as defined in claim 38;

and further comprising using the specified time interval of substantially 2.24 μ

s.

41. A method as defined in claim 38;

and further comprising making the specified time interval independent of a total length of the data telegram.

42. A method as defined in claim 33;

and further comprising protecting the synchronization information contained in the data telegram by a dedicated checksum.

43. A method as defined in claim 42;

and further comprising forming the checksum used to protect the synchronization information contained in the data telegram as a cyclic redundancy check.

44. A method as defined in claim 42;

and further comprising covering by the checksum a beginning of the data telegram up to and including the synchronization information.

45. A method as defined in claim 42;

and further comprising performing an evaluation of the checksum by the at least one further participant via a comparison with previously-stored checksums for known data telegram entries.

46. A method as defined in claim 42;

and further comprising locating the checksum after a subfield containing the synchronization information.

47. A method as defined in claim 42;

and further comprising locating the checksum directly at an end of a subfield containing the synchronization information.

48. A method as defined in claim 33;

and further comprising providing a beginning of the data telegram with a fixed reference to an instant of synchronization in the central participant.

49. A method as defined in claim 33;

and further comprising including in the data telegram a plurality of fields containing a preamble field, a destination address field, a source address field, a type field, a data field, and a checksum field, wherein a subfield with the synchronization information is located at a beginning of the data field, and a checksum field of the data telegram includes a checksum for an entire data telegram.

50. A method as defined in claim 33;

and further comprising including in a subfield with the synchronization information fields a type field, a phase field, and a checksum field, wherein the checksum field of the subfield includes a checksum that covers a beginning of a data telegram up to and including the phase field.

51. A method as defined in claim 33;

and further comprising evaluating the synchronization also when a checksum field of a subfield is valid and the checksum field of the data telegram is invalid.

52. A method as defined in claim 33;

and further comprising forming the data telegram as an amplifier telegram.

53. A method as defined in claim 43;

and further comprising forming the data telegrams as Ethernet telegrams.

54. A communication system, comprising a central participant;

at least one further participant being synchronized with a central participant by transmitting a telegram with synchronization information with the central participant to the at least one further participant, wherein the telegram is a data telegram.

55. A communication system as defined in claim 54, wherein a communication system is a distributed communication system for decentralized control with a master-slave structure.

56. A communication system as defined in claim 54, wherein the communication system is located in a structure selected from the group consisting of a ring structure, a linear bus topology, and a star topology.

57. A communication system as defined in claim 54, wherein the communication system is based on Ethernet physics.

58. An automation system, comprising a communication system including a central participant and at least one further participant being synchronized with a central participant by transmitting a telegram with synchronization information with the central participant to the at least one further participant, wherein the telegram is a data telegram;

a control unit; and

at least one further unit selected from the group consisting of an amplifier unit, an input unit, and an output unit, said control unit being connected with the central participant, and at least one of said further units being connected with one of further participants.

59. A telegram for synchronization in a communication system including a central participant and at least one further participant being synchronized with a central participant by transmitting a telegram with synchronization information with the central participant to the at least one further participant, wherein the telegram is a data telegram that includes the synchronization information.

60. A telegram as defined in claim 59, wherein entire contents of the telegram are protected by a checksum, and a portion of telegram contents is protected by a further checksum.

61. A telegram as defined in claim 60, wherein the checksum for protecting the entire contents of the telegram is located at an end of the telegram, while the further checksums are located in a front region of the telegrams.

62. A telegram as defined in claim 60, wherein a part of the telegram protected by the further checksum includes synchronization information, and a remaining part of the telegram contains operating data.

63. A telegram as defined in claim 59, wherein the data telegram is Ethernet telegram.