Abstract: A first initialization pattern signal is a signal in which a maximum signal level and a minimum signal level appear alternately, and a second initialization pattern signal is a signal in which all signal levels appear in a predetermined arrangement. In a ring-shaped network including plural stages of data transmission apparatuses (100), a transmission unit (110) of each data transmission apparatus outputs the first initialization pattern signal successively to a next-stage data transmission apparatus at turn-on of power or immediately after reset, and a reception unit (120) establishes clock synchronization on the basis of the first initialization pattern signal received.

Abstract: A digital data transmission apparatus includes a transmitting end (100) that includes: a binary/quadrary conversion unit (110) for converting a data stream; a coding unit (120) for mapping converted data to be coded; a digital filter (130); a D/A conversion unit (140); a low-pass filter (150) for attenuating noises which are caused by folding distortion; a differential driver (160); low-pass filters (170a) and (170b) for eliminating noises from differentially outputted signals; and a common mode choke coil (180) for eliminating common mode noises and outputting a resultant signal to a twisted pair cable (300), and a receiving end (200) that includes: a low-pass filter (210) for eliminating noises from the twisted pair cable; a receiver (220); an A/D conversion unit (230); a digital filter (240); an evaluation unit (250) for evaluating a signal level of a received signal; a decoding unit (260) for decoding the signal level into received data; and a synchronization unit (270) for generating a clock.

Abstract: It is an object to provide an evaluation level setting method for accurately evaluating signal levels, and a data reception apparatus, in multi-valued transmission for transmitting data while assigning one or more bits of data as one data symbol to a signal level.

Abstract: In a network of a topology of a loop and a bus, occurrence of a failure is detected and a location of the failure is specified. Occurrence of the failure is detected by detecting that a specific signal pattern to be received at regular time intervals within a fixed time period is not received. A node which has detected occurrence of the failure transmits or receives a specifying signal among the nodes, and decide whether or not the failure has occurred adjacently to itself. A packet indicating a decided location of the failure is transmitted or received among nodes, and thereby respective nodes specify the location of the failure. When the failure has occurred at the master node, a node having a smallest node ID after waiting time according to the node ID operates as the alternative master node.

Abstract: A communications system and a communications device are provided that can reduce the difference in data reaching time with a simple structure and can play audio without making listeners feeling strange. A communications device 105 is coupled to a network 101 and a device 106 such as a CD player or the like. The communications device 105 includes a network interface unit 100, a network controller 103 communicating with the device 106 and others, and a CPU controlling these components. Furthermore, the network interface unit 100, a transmission signal processing unit 107 and a reception signal processing unit 108 converts the data format appropriate for the network controller 103 and the network 101, respectively. A transmission scheme determination unit 102 determines the transmission scheme used among nodes. First and second switches 109 and 110 each have a contact A and a contact B, connecting either one of these contacts based on a control signal from the transmission scheme determination unit 102.

Abstract: A communications system and a communications device are provided that can reduce the difference in data reaching time with a simple structure and can play audio without making listeners feeling strange. A communications device 105 is coupled to a network 101 and a device 106 such as a CD player or the like. The communications device 105 includes a network interface unit 100, a network controller 103 communicating with the device 106 and others, and a CPU controlling these components. Furthermore, the network interface unit 100, a transmission signal processing unit 107 and a reception signal processing unit 108 converts the data format appropriate for the network controller 103 and the network 101, respectively. A transmission scheme determination unit 102 determines the transmission scheme used among nodes. First and second switches 109 and 110 each have a contact A and a contact B, connecting either one of these contacts based on a control signal from the transmission scheme determination unit 102.

Abstract: A master station 11 produces a token packet for isochronous data in which a slave station 12 and slave stations 13 and 14 serving as a sending station and receiving stations are designated using IDs for isochronous data “#2” and “#3” in accordance with contents described in a table 161 held in its inner part so as to manage a transmission bandwidth using a token packet sending/analysis executing device 16, and sends out the produced token packet to a transition path 15 on the downstream side. The slave station 12 sends out an isochronous data packet 42 using the token packet for isochronous data 41. According to the token packet for isochronous data 41, the slave stations 13 and 14 are designated as receiving stations using the ID for isochronous data “#3”, so that the slave stations 13 and 14 perform the above-mentioned operations, to receive the isochronous data packet 42.

Abstract: A network system comprises a main loop in which one master node which issues a token packet for data communication, and at least one slave node are connected in a loop; a first sub loop in which the master node, one sub-master node, and at least one slave node are connected in a loop; and at least one second sub loop in which the master node, at least two sub-master nodes including the sub-master node of the first sub loop, and at least one slave node are connected in a loop. In this network system, each node has an analysis execution unit which performs analysis of the token packet, control of data transmission and data reception, and a switch for changing the connection. When each node receives and analyzes the token packet, it controls the switch so as to output, transmit, or discard the token packet and a data packet. Therefore, addition of nodes and loops is facilitated while maintaining the transmission efficiency, without increasing the packet transmission time.

Abstract: A control device 3 determines whether an image generated by merging concurrently picked-up several images has consistent image quality on a display device 2. If determined No, image quality parameters set in each image pickup device 1 are so controlled as to make the image quality of the merged image consistent. Therefore, the merged image can assuredly have consistent image quality.

Abstract: The present invention provides a data transmission system comprising first and second source devices 102 and 103 for transmitting video data (isochronous data) 205 and 206 output from first and second data output units 1011 and 1012, and a sink device 101 for receiving the video data transmitted from the source devices and outputting the data to a video composition device 1020, in which the video data supplied from the data output units to the source device are synchronized in frame units and transmitted from the source devices to one sink device. In this data transmission system, synchronous information (reference signal information) 207a in the video composition device 1020 is transmitted from the sink device 101 to the source devices 102 and 103, and timing reference signals 208b1 and 208b2 in the data output units 1011 and 1012 are generated by the source devices on the basis of the synchronous information.

Abstract: A master station including at least a token packet (Iso) management table in which the overall band of the bus is partitioned into certain bands, rewrites the token packet (Iso) management table according to the bandwidth required in Isochronous data transmission between stations to at least control transmission of token packets (Iso) and dynamically control the bandwidth.