Method for synchronizing several digital input signals

• US 7,327,815 B1
• Filed: 11/30/1999
• Issued: 02/05/2008
• Est. Priority Date: 12/23/1998
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Jurisch, Andreas
• Primary Examiner(s): Fan; Chieh M.
• Assistant Examiner(s): PUENTE, EVA YI ZHENG
• Application Number:
  US09/868,773
• Time in Patent Office: 2,989 Days
• Field of Search: 375/354, 375/222, 375/232, 375/147, 375/355, 375/308, 375/350, 375/340, 375/295, 375/230, 375/240, 370/465, 370/536, 370/222, 341/61, 341/76
• US Class Current: 375/354
• CPC Class Codes: G06F 17/17 Function evaluation by approximation methods, e.g. inter- or extrapolation, smoothing, least mean square method G06F17/18 takes precedence ; interpolation for numerical control G05B19/18

Abstract

The invention relates to a method for synchronizing a plurality of digital input signals which are formed by sampling with the aid of a dedicated operating clock in each case.

In order to be able to carry out such a method reliably with a relatively low outlay, according to the invention digital auxiliary signals (xd(nk+j), (yd(nk+j)) are formed by sampling the digital input signals (x(k)) with the aid of a common postprocessing clock, use being made of a postprocessing clock which is at least twice as fast as the fastest operating clock; synchronized digital output signals (x(m), y(m)) which correspond to the digital input signals (x(k)) are formed by means of interpolating each digital auxiliary signal (xd(nk+j), yd(nk+j)).

Claims

1. A method for synchronizing a plurality of digital input signals formed by sampling analog input variables of measuring transducers,

wherein the measuring transducers are disposed at various points in an electric power supply system;

and

wherein the analog input variables are sampled with a dedicated operating clock;

the method comprising;

encoding each digital input signal using a signal encoder formed by a differentiator forming encoded digital input signals;

transmitting each encoded digital input signal from a transmission device via a transmission channel to a receiving device;

forming digital auxiliary signals using a signal resampling device by respectively sampling the received digital input signals with a common post-processing clock, which is at least twice as fast as a fastest operating clock; and

forming synchronized digital output signals corresponding to the digital input signals by interpolating each digital auxiliary signal using an interpolation filter formed by an integrator.

2. The method according to claim 1, further comprising:

filtering the synchronized digital output signals with an anti-aliasing filter directly after the interpolation.

3. The method according to claim 1, further comprising:

forming the digital auxiliary signals directly from the input signals and using an integrator for the interpolation when the digital input signals are formed from secondary variables of Rogovsky measuring transducers.