Modular numerical control having low-jitter synchronization

• US 20060093127A1
• Filed: 10/25/2005
• Published: 05/04/2006
• Est. Priority Date: 10/27/2004
• Status: Active Grant

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Zehentner, Georg
• Granted Patent: US 7,805,541 B2
• Time in Patent Office: Days
• US Class Current: 379/359
• CPC Class Codes: G01R 31/31709 Jitter measurements; Jitter generators measuring jitter, noise figure or signal-to-noise ratio per se G01R29/26; analysis of tester signals G01R31/31901
• CPC Class Codes: G01R 31/31726 Synchronization, e.g. of test, clock or strobe signals; Signals in different clock domains; Generation of Vernier signals; Comparison and adjustment of the signals
• CPC Class Codes: G05B 19/414 Structure of the control system, e.g. common controller or multiprocessor systems, interface to servo, programmable interface controller
• CPC Class Codes: G05B 2219/34001 PLL phase locked loop
• CPC Class Codes: H04J 3/0658 Clock or time synchronisation among packet nodes

Abstract

A modular, numerical control having low-jitter synchronization includes a main computer and at least one controller unit which, starting from the main computer, are interconnected by serial data-transmission channels in the form of a series circuit. The at least one controller unit includes a first receiver unit for receiving a serial data stream arriving from the direction of the main computer, and a first transmitter unit for outputting a serial data stream. Also provided in the at least one controller unit is a clock recovery unit which derives a synchronous clock signal from the serial data stream arriving at the first receiver unit, and supplies it to the first transmitter unit which uses it as a transmission clock signal, so that the serial data stream arriving at the first receiver unit and the serial data stream output by the first transmitter unit are coupled to each other in phase-locked manner.

Claims

1. A modular, numerical control unit having low-jitter synchronization, comprising:

a main computer; and

at least one controller unit, the at least one controller unit, starting from the main computer, interconnected by serial data transmission channels in the form of a series circuit, the at least one controller unit including;

a first receiver unit adapted to receive a serial data stream arriving from a direction of the main computer;

a first transmitter unit adapted to output a serial data stream; and

a clock recovery unit adapted to derive a synchronous clock signal from the serial data stream arriving at the first receiver unit and to supply the synchronous clock signal to the first transmitter unit, the synchronous clock signal used by the first transmitter unit as a transmission clock signal, the serial data stream arriving at the first receiver unit and the serial data stream output by the first transmitter unit coupled to each other in phase-locked manner.

2. The modular, numerical control according to claim 1, wherein the at least one controller unit includes a processor unit to which the synchronous clock signal is supplied, the processing unit adapted to process data included in the received serial data stream, at determined time intervals and to supply the processed data to the first transmitter unit.

3. The modular, numerical control according to claim 2, wherein the processor unit of the at least one controller unit is synchronizable by synchronization information transmitted in the serial data stream.

4. The modular, numerical control according to claim 1, wherein data in the serial data stream is transmittable as data packets.

5. The modular, numerical control according to claim 4, wherein the data packets include synchronization information.

6. The modular, numerical control according to claim 1, wherein the serial data stream is encoded such that level changes occur during transmission gaps.

7. The modular, numerical control according to claim 6, wherein the serial data stream has a bit group coding of a 4B5B type.

8. The modular, numerical control according to claim 1, wherein the at least one controller unit includes:

a second receiver unit adapted to receive a second serial data stream arriving from a direction of a final controller unit in the series circuit;

a processor unit adapted to process data included in the second serial data stream; and

a second transmitter unit adapted to output the processed data in the form of a serial data stream in the direction of the main computer.

9. The modular, numerical control according to claim 8, wherein the data transmission channels include a transmit channel and a receive channel, a serial data stream transmittable from the main computer in a direction of the controller units by the transmit channel, a serial data stream transmittable from the controller units in the direction of the main computer by the receive channel.

10. The modular, numerical control according to claim 8, wherein in the final controller unit of the series circuit, an output of the first transmitter unit is connected to an input of the second receiver unit.

11. A modular, numerical control unit having low-jitter synchronization, comprising:

main computing means; and

at least one controlling means, the at least one controlling means, starting from the main computing means, interconnected by serial data transmission means in the form of a series circuit, the at least one controlling means including;

first receiving means for receiving a serial data stream arriving from a direction of the main computing means;

first transmitting means for outputting a serial data stream; and

clock recovery means for deriving a synchronous clock signal from the serial data stream arriving at the first receiving means and for supplying the synchronous clock signal to the first transmitting means, the synchronous clock signal used by the first transmitting means as a transmission clock signal, the serial data stream arriving at the first receiving means and the serial data stream output by the first transmitting means coupled to each other in phase-locked manner.