Network device interface for digitally interfacing data channels to a controller via a network

• US 20040128423A1
• Filed: 12/04/2003
• Published: 07/01/2004
• Est. Priority Date: 12/08/2000
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Konz, Daniel W., Ellerbrock, Philip J., Grant, Robert L., Winkelmann, Joseph P.
• Granted Patent: US 7,058,737 B2
• Time in Patent Office: Days
• US Class Current: 710/305
• CPC Class Codes: H04L 12/40032 Details regarding a bus interface enhancer
• CPC Class Codes: H04L 12/4135 using bit-wise arbitration
• CPC Class Codes: H04L 2012/40215 Controller Area Network CAN
• CPC Class Codes: H04L 2012/4028 the transportation system being an aircraft
• CPC Class Codes: H04L 25/4904 using self-synchronising codes, e.g. split-phase codes

Abstract

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted into digital signals and transmitted back to the controller. In one embodiment, the bus controller sends commands and data a defined bit rate, and the network device interface senses this bit rate and sends data back to the bus controller using the defined bit rate.

Claims

1. A method for communicating between a bus controller and a at least one data data channel via a common digital bus, the method comprising:

transmitting a first message from the bus controller to the at least one data channel at a predetermined bit rate;

determining the predetermined bit rate at which the first message was transmitted upon receipt of the first message by the at least one data channel, where the determination is made independent of a synchronous clock signal from the bus controller;

transmitting a second message from the at least one data channel to the bus controller in response to the first message at the same predetermined bit rate; and

altering the predetermined bit rate and repeating said steps of transmitting the first message, determining the predetermined bit rate, and transmitting the second message.

2. A method according to claim 1 further comprising receiving the second message at the bus controller at the same predetermined bit rate independent of a synchronous clock signal.

3. A method according to claim 1 further comprising transmitting an example message from the bus controller to the at least one data channel at an altered bit rate following alteration of the predetermined bit rate and prior to transmission of the first message by the bus controller such that the altered bit rate can be determined upon receipt of the example message by the at least one data channel.

4. A method according to claim 1 further comprising sending a baud select command from the bus controller that defines a predetermined bit rate at which the subsequent first message will be transmitted.

5. A system for facilitating communications between a bus controller and at least one data channel via a common digital bus, the system comprising:

a bus controller connected to said common digital bus; and

a network device interface connected between the common digital bus and an associated data channel,

wherein said bus controller transmits a first message to said network device interface at a predetermined bit rate,

wherein said network device interface determines the predetermined bit rate at which the first message was transmitted upon receipt of the first message independent of a synchronous clock signal from said bus controller,

wherein said network device interface transmits a second message to said bus controller in response to the first message at the same predetermined bit rate,

wherein said bus controller alters the predetermined bit rate, and

wherein said bus controller and network device interface repeat transmission of the first message, determination of the predetermined bit rate, and transmission of the second message at the altered predetermined bit rate.

6. A system according to claim 5, wherein said bust controller receives the second message at the bus controller at the same predetermined bit rate independent of a synchronous clock signal.

7. A system according to claim 5, wherein said bus controller transmits an example message to the network device interface at an altered bit rate following alteration of the predetermined bit rate and prior to transmission of the first message by the bus controller such that the altered bit rate can be determined upon receipt of the example message by said network device interface.

8. A system according to claim 5, wherein said bus controller sends a baud select command to said network device interface that defines a predetermined bit rate at which the subsequent first message will be transmitted.

9. A system according to claim 5, wherein said network device interface uses the predetermined bit rate to communicate with the data channel associated therewith.

10. A network device interface adapted to interconnect a bus controller with an associated data channel via a common digital bus, the network device interface comprising:

a receiver for receiving messages from the bus controller via the common digital bus;

a device interface for providing commands to the associated data channel in response to messages received by said receiver and for receiving data from the associated data channel; and

a transmitter for transmitting messages to the bus controller via the common digital bus,

wherein said receiver comprises a clock detector for determining if synchronous clock signals are provided with the message and a bit rate detector for determining a bit rate at which the messages are received, wherein said transmitter transmits messages at the same bit rate at which messages are received, if said clock detector determines that the messages that are received are without any accompanying synchronous clock signals, and wherein said transmitter is capable of altering the bit rate at which messages are transmitted in accordance with alterations of the bit rate at which messages are received.

11. A network device interface according to claim 10 wherein said receiver receives an example message from the bus controller at an altered bit rate following alteration of the predetermined bit rate and prior to receipt of the first message at the altered bit rate such that said bit rate detector can determine the altered bit rate at which the example message is received.