Method and apparatus for transmitting data between a position measuring system and an evaluation unit

• US 6,320,502 B1
• Filed: 03/17/1998
• Issued: 11/20/2001
• Est. Priority Date: 03/18/1997
• Status: Expired due to Fees

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Hagl, Rainer
• Primary Examiner(s): Pope, Daryl
• Application Number:
  US09/040,015
• Time in Patent Office: 1,344 Days
• Field of Search: 340/538, 340/531, 340/679, 340/686.1, 340/686.2, 340/310.01, 340/310.02, 340/310.06
• US Class Current: 340/531
• CPC Class Codes: G05B 19/21 using an incremental digital measuring device

Abstract

A method for transmitting data between a position measuring system and an evaluating unit that includes the steps of generating a system-specific parameter, transmitting the system specific parameter between a position measuring system and an evaluating unit over at least one supply line.

Claims

1. A method for transmitting data between a position measuring system and an evaluating unit, the method comprising the steps of:

preparing a system-specific parameter that is a characteristic parameter of a position measuring system that determines the position of two parts movable relative to one another;

transmitting said system specific parameter between said position measuring system and an evaluating unit over at least one power supply line that supplies electrical power to said position measuring system so that said system specific parameter is transmitted along an electrically conductive path that is identical to an electrically conductive path upon which said supplied power follows.

2. The method of claim 1, wherein said system specific parameter comprises information on how a memory unit is organized.

3. The method of claim 1, wherein said system specific parameter comprises information on the type of said position measuring system.

4. The method of claim 1, wherein said transmitting step is performed at least intermittently.

5. The method of claim 1, wherein said system-specific parameter is transmitted in modulated form over said at least one power supply line.

6. The method of claim 1, wherein said system-specific parameter is transmitted bidirectionally over said at least one power supply line.

7. The method of claim 1, further comprising the steps of:

reading out said system-specific parameter out of a memory unit of said position measuring system;

preparing said system-specific parameter read out of said memory unit for transmission over said at least one power supply line; and

transmitting said prepared system-specific parameter to said evaluating unit.

8. The method of claim 1, further comprising the steps of:

selecting in said evaluating unit a certain system-specific parameter for the subsequent measuring operation of said position measuring system;

preparing said selected system-specific parameter for transmission over said at least one power supply line; and

transmitting said prepared system-specific parameter to said position measuring system.

9. The method of claim 8, comprising the step of storing said prepared system-specific parameter transmitted to said position measuring system in a memory unit in said position measuring system.

10. The method of claim 1, comprising the step of said position measuring system performing a measurement.

11. The method of claim 10, further comprising the steps of:

reading out said system-specific parameter out of a memory unit of said position measuring system;

preparing said system-specific parameter read out of said memory unit for transmission over said at least one power supply line; and

transmitting said prepared system-specific parameter to said evaluating unit.

12. The method of claim 10, further comprising the steps of:

selecting in said evaluating unit a certain system-specific parameter for the subsequent measuring operation of said position measuring system;

preparing said selected system-specific parameter for transmission over said at least one power supply line; and

transmitting said prepared system-specific parameter to said position measuring system.

13. The method of claim 11, wherein said reading out, preparing and transmitting steps are performed prior to said step of said position measuring system performing a measurement.

14. The method of claim 12, wherein said selecting, preparing and transmitting steps are performed prior to said step of said position measuring system performing a measurement.

15. The method of claim 1, further comprising the steps of:

preparing said system-specific parameter; and

separating said transmitted system specific parameter from said at least one power supply line.

16. The method of claim 15, wherein said preparing and separating steps are effected in said position measuring system and/or in said evaluating unit.

17. The method of claim 15, wherein said preparing and separating steps are effected by a respective modulator/demodulator unit.

18. The method of claim 1, further comprising the steps of:

transmitting a current and a voltage for the position measuring system over said one or more power supply lines.

19. An apparatus for transmitting data between a position measuring system and an evaluating unit, the apparatus comprising:

a position measuring system that determines the position of two parts movable relative to one another;

an evaluating unit;

at least one power supply line said position measuring system and said evaluating unit;

wherein said at least one power supply line supplies electrical power to said position measuring system;

a modulator unit connected to said at least one power supply line, said modulator unit prepares a system specific parameter that is transmitted over said at least one power supply line, wherein said system specific parameter is a characteristic parameter of said position measuring system and said system specific parameter is transmitted along an electrically conductive path that is identical to an electrically conductive path upon which said supplied power follows; and

a demodulator unit that decouples said system specific parameter from said at least one power supply line.

20. The apparatus of claim 19, wherein at least intermittently, a serial transmission of said system-specific parameter is effected between said position measuring system and said evaluating unit over said at least one power supply line.

21. The apparatus of claim 19, wherein said position measuring system comprises a memory unit into which said system-specific parameter can both be written into and read from via said at least one power supply line.

22. The apparatus of claim 21, wherein said memory unit is divided up into a plurality of regions with different access rights.

23. The apparatus of claim 22, wherein one of said plurality of regions is accessible only to the particular manufacturer of said position measuring system.

24. The apparatus of claim 22, wherein one of said plurality of regions may be written into and read out of by a user of said position measuring system.

25. The apparatus of claim 19, wherein said position measuring system comprises a filter element connected to said at least one power supply line over which a transmission of said system-specific parameter is effected.

26. The apparatus of claim 19, wherein said evaluating unit comprises a filter element connected to said at least one power supply line over which a transmission of said system-specific parameter is effected.

27. The apparatus of claim 19, wherein at least two signal transmission lines are disposed between said position measuring system and said evaluating unit, over which lines two phase-offset incremental signals can be transmitted from said position measuring system to said evaluating unit.

28. The apparatus of claim 27, comprising two further signal transmission lines, over which inverted signals, in comparison with said two phase-offset incremental signals, can be transmitted.

29. The apparatus of claim 19, comprising two signal transmission lines disposed between said position measuring system and said evaluating unit, said two signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

30. The apparatus of claim 27, further comprising two additional signal transmission lines disposed between said position measuring system and said evaluating unit, said two additional signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

31. The apparatus of claim 28, further comprising two additional signal transmission lines disposed between said position measuring system and said evaluating unit, said two additional signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

32. An apparatus for transmitting data between a position measuring system and an evaluating unit, the apparatus comprising:

a position measuring system that determines the position of two parts movable relative to one another;

an evaluating unit;

at least one power supply line that supplies electrical power to said position measuring system and said evaluating unit;

wherein at least two signal transmission lines are disposed between said position measuring system and said evaluating unit, over which said at least two signal transmission lines two phase-offset incremental signals can be transmitted from said position measuring system to said evaluating unit;

a modulator unit connected to said at least one power supply line, said modulator unit prepares a system specific parameter that is transmitted over said at least one power supply line, wherein said system specific parameter is significant for a planned measurement mode of said position measuring system and said system specific parameter is transmitted along an electrically conductive path that is identical to an electrically conductive path upon which said supplied power follows; and

a demodulator unit that decouples said system specific parameter from said at least one power supply line.

33. The apparatus of claim 32, comprising two further signal transmission lines, over which inverted signals, in comparison with said two phase-offset incremental signals, can be transmitted.

34. The apparatus of claim 32, comprising two signal transmission lines disposed between said position measuring system and said evaluating unit, said two signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

35. The apparatus of claim 32, further comprising two additional signal transmission lines disposed between said position measuring system and said evaluating unit, said two additional signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

36. The apparatus of claim 33, further comprising two additional signal transmission lines disposed between said position measuring system and said evaluating unit, said two additional signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

37. The apparatus of claim 32, wherein at least intermittently, a serial transmission of said system-specific parameter is effected between said position measuring system and said evaluating unit over said at least one power supply line.

38. The apparatus of claim 32, wherein said position measuring system comprises a memory unit into which said system-specific parameter can both be written into and read from via said at least one power supply line.

39. The apparatus of claim 38, wherein said memory unit is divided up into a plurality of regions with different access rights.

40. The apparatus of claim 39, wherein one of said plurality of regions is accessible only to the particular manufacturer of said position measuring system.

41. The apparatus of claim 39, wherein one of said plurality of regions may be written into and read out of by a user of said position measuring system.

42. The apparatus of claim 32, wherein said position measuring system comprises a filter element connected to said at least one power supply line over which a transmission of said system-specific parameter is effected.

43. The apparatus of claim 32, wherein said evaluating unit comprises a filter element connected to said at least one power supply line over which a transmission of said system-specific parameter is effected.

44. The apparatus of claim 32, wherein at least two signal transmission lines are disposed between said position measuring system and said evaluating unit, over which lines two phase-offset incremental signals can be transmitted from said position measuring system to said evaluating unit.

45. The apparatus of claim 44, comprising two further signal transmission lines, over which inverted signals, in comparison with said two phase-offset incremental signals, can be transmitted.

46. The apparatus of claim 32, comprising two signal transmission lines disposed between said position measuring system and said evaluating unit, said two signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

47. The apparatus of claim 44, further comprising two additional signal transmission lines disposed between said position measuring system and said evaluating unit, said two additional signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

48. The apparatus of claim 45, further comprising two additional signal transmission lines disposed between said position measuring system and said evaluating unit, said two additional signal transmission lines transmit reference pulse signals and signals inverted relative to said reference pulse signals.

49. A method for transmitting data between a position measuring system and an evaluating unit, the method comprising the steps of:

preparing a system-specific parameter that is significant for a planned measurement mode of a position measuring system that determines the position of two parts movable relative to one another;

transmitting said system specific parameter between said position measuring system and an evaluating unit over at least one power supply line that supplies electrical power to said position measuring system, wherein said system specific parameter is transmitted along an electrically conductive path that is identical to an electrically conductive path upon which said supplied power follows.

50. The method of claim 49, wherein said system specific parameter comprises information on the signal period and the measurement steps.

51. The method of claim 49, wherein said system specific parameter comprises information on the location of reference marks.

52. The method of claim 49, wherein said system specific parameter comprises information on the location of the zero point.

53. The method of claim 49, wherein said system-specific parameter is transmitted bidirectionally over said at least one power supply line.

54. The method of claim 49, further comprising the steps of:

reading out said system-specific parameter out of a memory unit of said position measuring system;

preparing said system-specific parameter read out of said memory unit for transmission over said at least one power supply line; and

transmitting said prepared system-specific parameter to said evaluating unit.

55. The method of claim 49, further comprising the steps of:

selecting in said evaluating unit a certain system-specific parameter for the subsequent measuring operation of said position measuring system;

preparing said selected system-specific parameter for transmission over said at least one power supply line; and

transmitting said prepared system-specific parameter to said position measuring system.

56. A method for transmitting data between a position measuring system and an evaluating unit, the method comprising the steps of:

preparing a system-specific parameter;

transmitting said system specific parameter between a position measuring system that determines the position of two parts movable relative to one another and an evaluating unit over at least one power supply line that supplies electrical power to said position measuring system, wherein said preparing and transmitting steps are performed prior to said position measuring system performing a measurement that determines said position, wherein said system specific parameter is transmitted along an electrically conductive path that is identical to an electrically conductive path upon which said supplied power follows.

57. The method of claim 56, further comprising the steps of:

reading out said system-specific parameter out of a memory unit of said position measuring system;

preparing said system-specific parameter read out of said memory unit for transmission over said at least one power supply line; and

transmitting said prepared system-specific parameter to said evaluating unit.

58. The method of claim 56, further comprising the steps of:

selecting in said evaluating unit a certain system-specific parameter for the subsequent measuring operation of said position measuring system;

preparing said selected system-specific parameter for transmission over said at least one power supply line; and

transmitting said prepared system-specific parameter to said position measuring system.

59. The method of claim 58, comprising the step of storing said prepared system-specific parameter transmitted to said position measuring system in a memory unit in said position measuring system.

60. The method of claim 58, wherein said selecting step is performed prior to said position measuring system performing said measurement.