Measuring machine communication with automatic address allocation

Patent metadata

Field	Value
Publication number	US-10218672-B2
Application number	US-201314426119-A
Country	US
Kind code	B2
Filing date	Sep 4, 2013
Priority date	Sep 5, 2012
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

The invention relates to a method for allocating participant-specific communication addresses for participants in a measuring system such as, for example, a position measuring system of a coordinate measuring device with measuring sensors as participants. In the measuring system, the participants communicate via a bus system using messages with at least one communication address and message content. The messages transmitted by one participant are received by each of the other participants. The participant-dedicated communication addresses are ascertained as part of a calibrating or referencing process in which the participants monitor the messages on the bus system. If a collision by a communication address of a received message is detected, wherein the address matches the participant-dedicated communication address, a participant-dedicated communication address, which has been changed and has not collided with the received message, of the participant is allocated to said participant as a result of the collision.

First claim

What is claimed is:

1. A method for address allocation of participant-specific communication addresses for participants in a measuring system, the method comprising:
performing a communication between the participants, which communication takes place via a bus system by means of messages with at least one communication address and a message content, wherein in the bus system the messages that are communicated by any of the participants are received by all other participants;
carrying out an automatic address iteration for at least one of the participants during a calibration or referencing of the measuring system, wherein the automatic address iteration comprises:
monitoring of the messages on the bus system; and
detecting of a collision by a communication address of a received message, which is identical to a participant-dedicated communication address of the at least one of the participants;

providing a collision-related allocation of a changed participant-dedicated communication address of the at least one of the participants to the at least one of the participants, which changed participant-dedicated communication address does not collide with the communication address of the received message; and
performing a defined stimulation of at least one sensor of the at least one of the participants to obtain one or more sensor values, which defined simulation is carried out within the calibration or referencing of the measuring system; and
performing a determination of an address-device allocation of the participants in the measuring system, which determination takes place using the one or more sensor values obtained by the defined stimulation.

2. The method as claimed in claim 1 , wherein:
for the automatic address iteration, each of the participants providing a provided message transmitted by the respective participant, each provided message having a participant-specific message content; and
in a case of identical communication addresses, establishing a high probability of collision of the provided messages from the participants through the participant-specific message content of each provided message.

3. The method as claimed in claim 2 , further comprising:
forming the participant specific message content of the provided messages from all of the participants using a sensor measurement value defined by the respective participant for the respective participant specific message content.

4. The method as claimed in claim 2 , further comprising:
forming the participant specific message content of the provided messages from all of the participants using a random number generated in the respective participant for the respective participant specific message content.

5. The method as claimed in claim 2 , further comprising:
performing an allocation of a new participant-dedicated communication address using a mapping function for a participant which detects a collision in the detecting of the collision by the communication address of the received message; wherein:
the mapping function is designed in such a way that the automatic address iteration converges towards participant-specific addresses for all of the participants of the measuring system,
wherein the mapping function depends on the participant specific message content provided by the respective participant.

6. The method as claimed in claim 5 , further comprising:
defining of the new participant-dedicated communication address takes place using the mapping function, which is effected by incorporating a difference between messages in the detecting of the collision by the communication address of the received message, in order to avoid a simultaneous, similar change of the communication address in a plurality of the participants.

7. The method as claimed in claim 1 , wherein:
a participant, when allocating a changed communication address to itself, transmitting a message with its old and its new address.

8. The method as claimed in claim 1 , wherein:
the collision-related allocation of a changed participant-dedicated communication address is activatable or deactivatable; and
wherein, after receiving a specific lock message, one or more of the participants fixes its participant-dedicated communication address and carries out no further allocation of a changed communication address to itself, wherein, by means of a reset message, a reset signal or through shutdown of the participants, the collision-related allocation of a changed participant-dedicated communication address is reactivated.

9. The method as claimed in claim 8 , further comprising:
when attempting a subsequent detecting of a collision by a communication address of a received message is free from collisions, a convergence of the automatic address iteration is detected and the collision-related allocation of a changed participant-dedicated communication address is deactivated, wherein a unique participant-dedicated communication address for each participant is stored in a non-volatile memory following the convergence of the automatic address iteration,
wherein the stored communication address for each participant serves in future as an initial value for a subsequent new address iteration.

10. The method as claimed in claim 1 , further comprising:
storing the participant-dedicated communication address only in volatile form in the at least one of the participants.

11. The method as claimed in claim 1 , wherein:
communication interfaces of the bus system are designed according to RS422, RS423, RS323 or RS485 specification;
wherein all participants are additionally connected to a global, common clock trigger signal line, by which
a synchronization of participant-internal, local clock signals takes place in the participants, which are used for communication and/or measurement value acquisition in the participants, and a triggering of an acquisition of a measurement value.

12. A participant in a two-way measuring system communication,
which has:
a message processor which is designed in such a way that it carries out the automatic address iteration method as claimed in claim 1 ; and
at least one communication interface operable by the message processor for a communicative connection to at least one further participant via messages on the bus system, which is part of the two-way measuring system communication, wherein in the bus system a message transmitted is receivable by all participants of the bus system.

13. The participant as claimed in claim 12 , wherein:
the participant has a random number generator and/or a measurement value sensor and an establishment of a high probability of collision of the message on the bus system of the two-way measuring system communication takes place for the automatic address iteration in the case of identical participant-dedicated communication addresses with a participant-specific message content as a potentially participant-unique value of the random number generator and/or the measurement value sensor.

14. The participant as claimed in claim 12 , comprising a measurement value sensor in a position-measuring system of a Coordinate Measurement Machine (CMM).

15. A coordinate-measuring system comprising:
a communication system with measurement value sensors as participants of the communication system, which participants of the communication system are configured to operate with the method claimed in claim 1 ; and
at least one exchangeable device which is exchangeable in operation, is configured to be connected to the communication system as at least one participant of the communication system.

16. One or more non-tra

Assignees

• Hexagon Technology Ct Gmbh

Inventors

• Fritsch Robert

Classifications

• H04L2012/4026

  Bus for use in automation systems · CPC title

• H04L61/2038

  Electricity · mapped topic

• G01D21/00

  Measuring or testing not otherwise provided for · CPC title

• H04L61/2046 Primary

  Electricity · mapped topic

• H04L67/12

  specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks · CPC title