Systems, device, and methods related to estimating a Signal to Noise Ratio (SNR) of a signal are disclosed. A method of estimating an SNR includes setting a threshold of a comparator of a physical layer device to a first value, applying a signal to the comparator, and determining a first bit error number of an output of the comparator with the threshold set at the first value. The method also includes setting the threshold of the comparator to a second value that is different from the first value, applying the signal to the comparator, and determining a second bit error number of the output of the comparator with the threshold set at the second value. The method further includes determining an SNR of the signal based on the first bit error number and the second bit error number.

In some embodiments, a motor drive system includes a communication subassembly electrically coupled to a control subassembly for providing communication between the control subassembly and at least one external device. The control subassembly and the communication subassembly transmit and receive control data independently of messaging data, greatly enhancing performance and reducing the workload of processors on the control subassembly and communication subassembly. Additionally, the control subassembly and the communication subassembly transmit message data via sequence count based messaging. Communications between the communication subassembly and the control subassembly may include a series of timeout periods and retries, increasing reliability.

A method for shaping traffic across a wide area network is disclosed. The method involves advertising a data rate limit across a wide area network (WAN) from a first node, measuring the rate of data received at a WAN interface of the first node, and, if the measured rate of data received at the WAN interface of the first node exceeds a maximum threshold, advertising a reduced data rate limit across the WAN, and, if the measured rate of data received at the WAN interface of the first node is below a minimum threshold, advertising an increased data rate limit across the WAN.

A controller area network (CAN) communication method for electronic devices of a vehicle includes: transmitting data using a data frame in which communication mode information designating high speed CAN communication processing or general CAN communication processing is inserted into a null bit or a reserved bit that is not used in a general CAN communication protocol; receiving the transmitted data; and processing the received data in a high speed CAN communication mode or a general CAN communication mode based on the communication mode information.

There is provided an interface circuit, a network switch or network device coupler incorporating the interface circuit, and a network incorporating the network switch or network device. The interface circuit has a data bus interface (7) for connecting a data bus to either a first device (6) that communicates in a first signalling protocol or a second device (6) that communicates in a second signalling protocol. The data bus has two bus conductors that provide combined power and data. A voltage source (12) powers the data bus. The voltage source (12) is connected to the data bus via a reactance (10) and then a first resistance (4) connected in series. An output of a transmitter (13) is connected via a second resistance (3) to a point between the reactance (10) and the first resistance, to modulate the data bus.

An error detection test device for a subscriber station of a serial bus system. The error detection test device has an evaluation module for evaluating which bit of a signal must be interrupted so that the receivers of the resulting signal in which the at least one bit is interrupted can check the function of an error detection mechanism, the signal being processed by a protocol control unit while the subscriber station is in operation in order to be able to be transmitted as a frame onto a bus of the bus system or, after a frame has been received from the bus, to decode the signal from the frame, and an output terminal for outputting a switching signal to the protocol control unit to interrupt the at least one bit. The evaluation module generates the switching signal based on the at least one bit evaluated by the evaluation module.

A device and method for a serial bus system. The device has a transmit signal analysis module for counting edges of a transmit signal to be transmitted on a bus of the bus system; a receive signal analysis module for counting edges of a receive signal generated from a signal transmitted on the bus because of the transmit signal; and an evaluation module for evaluating the difference that results from a comparison of the edges counted by the transmit signal analysis module and the edges counted by the receive signal analysis module. If the signal propagation time on the bus is greater than the bit time of the receive signal, the evaluation module signals whether the amount of the difference is less than or equal to a predefined value or whether the amount of the difference is greater than the predefined value, the predefined value being greater than zero.

A user station for a serial bus system and a method for transmitting a message in a serial bus system. The user station includes a communication control device for transmitting messages to a bus of the bus system and/or for receiving messages from the bus of the bus system, and a bit rate switchover unit for switching over a bit rate of the messages from a first bit rate in a first communication phase to a second bit rate for a second communication phase. The bit rate switching unit is designed to switch the bit rate from the first bit rate over to the second bit rate, due to an edge of a predetermined bit sequence that includes one bit of the first communication phase and one bit of the second communication phase.

A user station for a serial bus system and a method for communication in a serial bus system. The user station includes a communication control unit, and a transceiver unit for transmitting a transmit signal for a message which is exchanged between user stations of the bus system. The bit time of a signal transmitted in the first communication phase on the bus differs from a bit time of a signal transmitted in the second communication phase. The communication control unit generates the transmit signal according to a frame, in which in addition to a field which indicates the priority of the message, a field for a data type is provided, and the communication control unit being designed to write a value in the field for the data type which indicates which type of information is located in a data field of the frame.

The invention realizes a gateway device capable of shortening the time required for routing to a CAN bus of the opposite microcomputer side and reducing the delay of data transfer. If the indexes are the same, a microcomputer 1 and a microcomputer 2 include common routing tables 10 and 20 in which the same contents are defined. The microcomputer 1 sends the index to the microcomputer 2. The microcomputer 2 that has received the index reads the routing rule defined in the common routing table 20 by the received index.