Device and process for acquisition of measurments using a digital communication bus, particularly used during aircraft tests

• US 20030179715A1
• Filed: 03/14/2003
• Published: 09/25/2003
• Est. Priority Date: 03/15/2002
• Status: Active Grant

• Current Assignee: Airbus Operations SAS (Airbus SE)
• Original Assignee: Airbus France
• Inventors: Viard, Laurent, Freaud, Gilles, Perez, Pierre
• Granted Patent: US 6,937,957 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: G06F 13/4291 using a clocked protocol

Abstract

The invention relates to a device for acquisition of measurements using a digital communication bus (10) and a computer system, comprising:

a bus arbitrator (11) connected to this bus (10), with the function of acting as the bus master and which synchronizes measurements made using sensors (14),

several items of slave equipment (13) connected on this bus (10), to which these sensors (14) are connected,

two line termination devices; the first being integrated in the bus arbitrator (11) and the second being integrated into slave equipment (13) at the other end of the bus (10) opposite the bus arbitrator (11).

The invention also relates to a measurement acquisition process.

Claims

1. Device for acquisition of measurements using a digital communication bus (10) and a computer system characterized in that it comprises:

a bus arbitrator (11) connected to this bus (10), with the function of acting as the bus master and which synchronizes measurements made using sensors (14),

several items of slave equipment (13) connected on this bus (10), to which these sensors (14) are connected,

two line termination devices;

the first being integrated in the bus arbitrator (11) and the second being integrated into slave equipment (13) at the other end of the bus (10) opposite the bus arbitrator (13).

2. Device according to claim 1, comprising at least one intelligent sensor (16) comprising at least one measurement channel connected directly to the bus (10).

3. Device according to claim 1, in which the bus (10) is composed of a cable with two shielded twisted pairs (2p):

a first pair being used for data exchanges between the bus arbitrator (11) and slave equipment (13),

a second pair being used for transporting a data validation clock.

4. Device according to claim 1, in which the bus is split into several segments, the ends of which are connected to connectors (18) of slave equipment (13), one end of one of the segments being connected to the bus arbitrator (11), the interconnections between these various segments and the connection lines between the slave equipment (13) and the bus (10) being made within the slave equipment (13).

5. Device according to claim 1, comprising at least one junction element (19) that can replace slave equipment (13), the connection of this junction element being compatible with the connection of this slave equipment to guarantee continuity of the bus and the bus shielding.

6. Device according to claim 1, in which the slave equipment is composed of two types of multiplexers:

multiplexers of a first type (13), each of which receives 16 analog input channels,

multiplexers of a second type (13′

), each of which receives 32 analog inputs.

16. Use of the measurement acquisition device according to claim 1 during tests on an aircraft.

7. Process for the acquisition of measurements using a digital communication bus (10), a computer system, a bus arbitrator (11) connected to this bus (10) which acts as bus master and which synchronizes measurements made using sensors (14), and several items of slave equipment (13) connected to this bus (10) to which these sensors are connected, characterized in that the bus arbitrator (11) uses a cyclic exchange of variables to acquire measurements from sensors (14) through the slave equipment (13).

8. Process according to claim 7, in which the bus arbitrator (11) comprises a scanning table composed of an ordered sequence of identifiers of variables to be queried during an elementary data scanning cycle.

9. Process according to claim 8, in which this table is fixed and unchangeable.

10. Process according to claim 9, in which this table comprises two parts;

a first part related to the acquisition of measurements, a second part related to the acquisition of status variables of the different slave equipment.

11. Process according to claim 7, in which the bus arbitrator (11) uses a non-periodic exchange of variables to make data transfers either from the said bus arbitrator (11) to the slave equipment (13), or from slave equipment (13) to the said bus arbitrator (11).

12. Process according to claim 11, in which the bus arbitrator (11) orders the circulation of a start download/remote read data transfer identification frame to trigger the data transfer.

13. Process according to claim 12, in which, in the case of a transfer of download data only, the slave equipment (13) that receives the data begins by acknowledging the received identification frame, and is then followed by an exchange of data sent by the bus arbitrator (11) (download) or by the sending slave equipment (13) (remote read), with an acknowledgement of each exchange by the data receiver.

14. Process according to claim 13, in which, in the case of a transfer of download data, the bus arbitrator (11) terminates the exchange by sending an end of transaction indication frame that is acknowledged by the slave equipment concerned.

15. Process according to claim 12, in which, in the case of a transfer of remote read data, the sending slave equipment indicates the end of the exchange by sending an end of transaction indication frame to the bus arbitrator.