DIGITAL MULTIMETER HAVING REMOTE DISPLAY WITH AUTOMATIC COMMUNICATION MODE SWITCHING

• US 20100181990A1
• Filed: 01/21/2009
• Published: 07/22/2010
• Est. Priority Date: 01/21/2009
• Status: Active Grant

• Current Assignee: Fluke Corporation (Fortive Corp.)
• Original Assignee: Fluke Corporation (Fortive Corp.)
• Inventors: Wetzel, Nathaniel J., Hudson, Jeffrey C.
• Granted Patent: US 8,358,121 B2
• Time in Patent Office: Days
• US Class Current: 324/115
• CPC Class Codes: G01R 15/125 for digital multimeters
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: G08C 23/04 using light waves, e.g. infrared
• CPC Class Codes: H04Q 2209/40 using a wireless architecture
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A multimeter comprising a base unit having at least one test lead terminal. A remote display unit separate from the base unit is also provided. The remote display unit has a display operative to show measured parameters. The multimeter further comprises communication circuitry operative to provide electrical communication between the base unit and the remote display unit. The communication circuitry provides electrical communication in a plurality of alternative communication modes. At least two of the alternative communication modes are preferably wireless communication modes.

Claims

1. A multimeter comprising:

a base unit having at least one test lead terminal;

a remote display unit separate from said base unit, said remote display unit having a display operative to show measured parameters; and

communication circuitry operative to provide electrical communication between said base unit and said remote display unit, said communication circuitry capable of said electrical communication in a plurality of alternative communication modes.

2. A multimeter as set forth in claim 1, wherein said at least two of said communication modes are wireless communication modes.

3. A multimeter as set forth in claim 2, wherein a first communication mode of said wireless communication modes is an optical communication mode.

4. A multimeter as set forth in claim 3, wherein said optical communication mode is an IR communication mode.

5. A multimeter as set forth in claim 2, wherein a second communication mode of said wireless communication modes is an RF communication mode.

6. A multimeter as set forth in claim 1, wherein said communication circuitry provides electrical communication in a first communication mode when said remote display unit is located adjacent to said base unit and in a second communication mode when said remote display unit is located apart from said base unit.

7. A multimeter as set forth in claim 6, wherein a first communication mode is an IR communication mode.

8. A multimeter as set forth in claim 6, wherein a second communication mode is an RF communication mode.

9. A multimeter as set forth in claim 6, wherein said communication circuitry attempts to establish communication from said base unit in an IR communication mode and then switches to an RF communication mode if IR communication is unsuccessful.

10. A multimeter as set forth in claim 1, wherein said remote display unit is matable with said base unit.

11. A multimeter as set forth in claim 10, wherein said base unit has a receiving portion at which said remote display is slidably mated.

12. A multimeter as set forth in claim 10, further comprising a latching mechanism which releasably retains said remote display unit in mated relationship with said base unit.

13. A multimeter as set forth in claim 10, wherein said base unit includes:

a rotary selector knob; and

wherein said at least one test lead terminal comprises a plurality of test lead jacks.

14. A multimeter as set forth in claim 1, wherein said remote display unit has an end surface canted at an acute angle relative to perpendicular such that said display will be tilted when said remote display unit is placed on a horizontal surface.

15. A multimeter as set forth in claim 1, wherein said remote display unit is adapted to be placed on a vertical surface.

16. A multimeter as set forth in claim 15, wherein said remote display unit includes an internal magnet to retain said remote display unit on said vertical surface.

17. A multimeter as set forth in claim 1, wherein said remote display unit has a plurality of display function buttons located thereon.

18. A method of establishing electrical communication between a base unit and a separate remote display unit of an electrical test instrument, said method comprising steps of:

(a) with one of said base unit and said remote display unit, sending a request for response via an IR communication mode to the other of said base unit and said remote display unit;

(b) if a response to said request for response is received at said one of said base unit and said remote display unit, then maintaining communication with the other of said base unit and said remote display unit in an optical communication mode; and

(c) if a response to said request for response is not received at said one of said base unit and said remote display unit, then establishing communication with the other of said base unit and said remote display unit in an RF communication mode.

19. A method as set forth in claim 18, wherein said base unit sends said response for response to said remote display unit.

20. A method as set forth in claim 18, wherein said optical communication mode is an RF communication mode.

21. An electrical test instrument comprising:

a base unit;

a remote display unit separate from but matable with said base unit, said remote display unit having a display operative to show measured parameters;

communication circuitry operative to provide electrical communication between said base unit and said remote display unit; and

said communication circuitry operative to provide electrical communication in a first communication mode when said remote display unit is mated with said base unit and a second communication mode when said remote display unit is located apart from said base unit.

22. An electrical test instrument as set forth in claim 21, wherein said first and second communication modes are wireless communication modes.

23. An electrical test instrument as set forth in claim 22, wherein said first communication mode is an optical communication mode.

24. An electrical test instrument as set forth in claim 23, wherein said optical communication mode is an IR communication mode.

25. An electrical test instrument as set forth in claim 21, wherein said second communication mode is an RF communication mode.

26. An electrical test instrument as set forth in claim 21, wherein said base unit has a receiving portion at which said remote display is slidably mated.

27. An electrical test instrument as set forth in claim 26, further comprising a latching mechanism which releasably retains said remote display unit in mated relationship with said base unit.

28. A multimeter comprising:

a base unit having a plurality of test lead jacks and a rotary selector knob;

a remote display unit separate from but matable with said base unit, said remote display unit having a display operative to show measured parameters;

communication circuitry operative to provide electrical communication between said base unit and said remote display unit;

said communication circuitry operative to provide electrical communication in a first communication mode when said remote display unit is mated with said base unit and a second communication mode when said remote display unit is located apart from said base unit; and

wherein said first and second communication modes are wireless communication modes.

29. A multimeter as set forth in claim 28, wherein said first communication mode is an optical communication mode.

30. A multimeter as set forth in claim 29, wherein said optical communication mode is an IR communication mode.

31. A multimeter as set forth in claim 28, wherein said second communication mode is an RF communication mode.

32. A multimeter as set forth in claim 28, wherein said remote display unit has a plurality of display function buttons located thereon.