Process for testing an electronic electricity meter

• US 5,644,222 A
• Filed: 03/24/1995
• Issued: 07/01/1997
• Est. Priority Date: 09/24/1992
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Windsheimer, Klaus, Dohmstreich, Wolfgang
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): Bowser, Barry
• Application Number:
  US08/403,871
• Time in Patent Office: 830 Days
• Field of Search: 324/74, 324/140, 324/141, 324/142, 324/120, 324/121, 324/126, 324/127, 340/539, 340/870.02, 364/480-483
• US Class Current: 324/74
• CPC Class Codes: G01R 35/04 of instruments for measuring time integral of power or current

Abstract

The invention relates to an electronic electricity meter (1) having an optical interface (5, 6), which is used to test the load curve of the meter. To this end, after a test message is received from a testing unit (7, 8, 9), the microcomputer (2) of the meter (1) applies load meter pulses to the optical interface (5, 6).

Claims

1. A method for testing an electricity meter including a light emitting diode and an optical interface having an infrared transmitting diode, said method comprising the steps of:

applying a test load having a predetermined energy level to the electricity meter;

generating a first plurality of meter pulses having a frequency corresponding to the predetermined energy level;

dividing the first plurality of meter pulses to form a second plurality of meter pulses;

feeding the second plurality of meter pulses to the light emitting diode;

causing the light emitting diode to generate a visible display representing the predetermined energy level of the test load; and

transmitting a first request message to the optical interface to initiate an injection of at least one of the first and second plurality of meter pulses to the infrared transmitting diode.

2. The method of claim 1, wherein the plurality of meter pulses fed to the light emitting diode have a maximum operating flashing frequency of 15 Hz.

3. The method of claim 1, wherein said second plurality of meter pulses is injected into the infrared transmitting diode for a predetermined time period, after which a status inquiry is initiated by transmitting a second external request message to the optical interface, said status inquiry comprising outputting status data through the optical interface.

4. The method of claim 2, wherein the electricity meter maintains said status data in a status register.

5. The method of claim 2, wherein said status inquiry immediately follows said meter measurement, said method further comprising the steps of:

switching off the test load if said meter measurement terminates prior to expiration of the predetermined time period for feeding said second plurality of meter pulses to said light emitting diode; and

transmitting said second request message to the optical interface while the test load is switched off.

6. The method of claim 1, wherein said first plurality of meter pulses has a higher frequency than said second plurality of meter pulses.

7. The method of claim 2, wherein said status data comprises information about one or more control lines for a microcomputer included in the electricity meter.

8. An electricity meter comprising:

a microcomputer;

an optical interface coupled to said microcomputer and including an infrared transmitting diode;

a power/frequency converter coupled to said microcomputer;

a divider coupled to the power/frequency converter;

a light emitting diode coupled to the divider; and

a means for applying a test load having a predetermined energy level to said power/frequency converter, wherein after a test load has been applied to the electricity meter, said power/frequency converter converts the test load to a first plurality of meter pulses having a frequency corresponding to the predetermined energy level, and feeds said plurality of meter pulses to said divider, said divider divides said first plurality of meter pulses to form a second plurality of meter pulses which are fed to said emitting diode,

wherein a receipt by said optical interface of an external request for a meter measurement causes switching means to switch one of the first and second plurality of pulses to said infrared transmitting diode, and

wherein the light emitting diode provides a visual indication of the predetermined energy level.

9. The electricity meter of claim 8, further comprising a memory for maintaining information pertaining to a status of the electricity meter, wherein said status information is communicated by outputting a status word through said optical interface.

10. The electricity meter of claim 8, wherein said microcomputer outputs status data through said optical interface in response to an external request for a status inquiry.