Method for Exchanging Information Among Digital Units In a Distributed System

• US 20090097504A1
• Filed: 07/25/2006
• Published: 04/16/2009
• Est. Priority Date: 07/28/2005
• Status: Active Grant

• Current Assignee: IMA - Industria Macchine Automatiche SPA (Vacchi Family)
• Original Assignee: I.M.A. Industria Macchine
• Inventors: Tilli, Andrea, Mazzuchetti, Graziano, Potenza, Leonardo, Ragazzini, Pierantonio, Rossi, Carlo
• Granted Patent: US 8,462,796 B2
• Time in Patent Office: Days
• US Class Current: 370/498
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: H04L 7/02 Speed or phase control by the received code signals, the signals containing no special synchronisation information H04L7/0075 takes precedence
• CPC Class Codes: H04L 7/0331 with a digital phase-locked loop [PLL] processing binary samples, e.g. add/subtract logic for correction of receiver clock H04L7/0337 takes precedence

Abstract

Method for exchanging information among digital units in a distributed system, with digital units being defined by at least a master node and slave nodes, comprising the step of transferring information references from said master node to said slave nodes, said information references being sampled with sampling time corresponding to a cycle time period defined by clock value of said master node; wherein the method comprises further steps of estimating the number of said information references sampled arrived to said slave node from said master node during a periodic reference time interval, and using said number to recalculate the master clock value, so that said slave nodes are able to reconstruct master node information reference during a following reference time interval.

Claims

1. Method for exchanging information among digital units in a distributed system, with digital units being defined by at least a master node and slave nodes, comprising the step of transferring information references from said master node to said slave nodes, said information references being sampled with sampling time corresponding to a cycle time period defined by clock value of said master node;

wherein the method comprises further steps of estimating the number of said information references sampled arrived to said slave node from said master node during a periodic reference time interval, and using said number to recalculate the master clock value, so that said slave nodes are able to reconstruct master node information reference during a following reference time interval.

2. Method according to claim 1, wherein said recalculation is realized by a linear interpolation and by using a buffer for storing more master node samples.

3. Method according to claim 2, wherein said buffer is a first in-first out type buffer.

4. Method according to claim 1, wherein said slave nodes are linked with respective electromechanical axes of an automatic packaging machine, the motion of which is to be controlled.

5. Method according to claim 2, wherein said slave nodes are linked with respective electromechanical axes of an automatic packaging machine, the motion of which is to be controlled.

6. Method according to claim 1, wherein said slave nodes are linked with respective electromechanical axes of an automatic packaging machine, the motion of which is to be controlled.

7. Method according to claim 1, wherein said information references comprise at least a couple of values, one of such value being a time value.

8. Method according to claim 2, wherein said information references comprise at least a couple of values, one of such value being a time value.

9. Method according to claim 3, wherein said information references comprise at least a couple of values, one of such value being a time value.

10. Method according to claim 4, wherein said information references comprise at least a couple of values, one of such value being a time value.

11. Method according to claim 10, wherein said information references comprise at least a couple of values, one of such value being a time value.

12. Method according to claim 11, wherein said information references comprise at least a couple of values, one of such value being a time value.