摘要:
A multiplex transmission system includes a plurality of multiplex nodes interconnected by a common multiplex transmission line. Data frames are transmitted among the multiplex nodes through the multiplex transmission line. A data frame transmitted from a sending multiplex node includes a data area which is divided into subdivided areas in accordance with data transmitted therefrom and data transmitted from receiving multiplex nodes which send data in response to a send request, in accordance with the number of data pieces or the number of bits, and the receiving nodes send data to respective subdivided areas in a predetermined order, to thereby carry out a data transmission. Accordingly, the sending multiplex node can simultaneously collect data from the receiving multiplex nodes which are functionally subordinate. When any of the receiving multiplex nodes fails to return an ACK signal, the sending multiplex node retransmits the data frame.
摘要:
When a message is transmitted, frame by frame, from any one (10) of a plurality of multiplex nodes to a common multiplex bus (MB) to which the multiplex nodes are connected, each of the multiplex nodes (20 and 30) determines that transmission of a frame therefrom is allowed when it detects a transmission permission signal (b, b') added to the frame after detection of and idle state of the multiplex bus, and starts transmitting a message data frame. This makes it possible to properly implement priority-based control according to the priority levels of the data frames irrespectively of variations in the reference clocks of the multiplex nodes. Further, receiving multiplex nodes perform frame synchronization at the rise of a special code (a) of a start code (SOM) of a message data frame, and then perform re-synchronization at the rise of a special bit pattern (b") which includes a passive bit and a dominant bit. This prevents synchronization from being deviated and bit errors resulting from deviated synchronization, thus leading to higher reliability of multiplex transmission.
摘要:
A multiplex transmission system according to the present invention is provided with a plurality of multiplex nodes which are connected in parallel with two common buses so that data are transmitted between the nodes. A receiver circuit of each multiplex node includes a passive potential detector section and bias sections. In case of any trouble on the buses, in this multiplex transmission system, the passive potential detector section detects the respective passive-mode potentials of the buses, controls the bias sections in accordance with the detected passive potentials, and sets input potentials within a predetermined range, thereby enabling data transmission between the multiplex nodes.
摘要:
Multiplex nodes (11, 12) connected via multiplex transmission lines (A, B and C), a voltage setting unit 16, which changes the voltage of the multiplex transmission line C to a specified value, a controller IC 14, which detects a failure in the multiplex transmission lines A and B, a protective circuit 15, which writes specified address data received from the controller IC 14 and key word data and sends a state signal corresponding to these pieces of data to the voltage setting unit 16, and a controller IC 14 which writes these pieces of data in a predetermined area of the protective circuit 15 are provided. The controller IC 14 detects a failure, the voltage setting unit 16 connects the specified multiplex transmission line C to a power supply or ground according to a state signal received from the protective circuit 15, thus changing the states of the multiplex transmission lines A and B.
摘要:
A passenger detecting apparatus determines the presence of a passenger or an object, such as a child seat, in a seat unit, estimates the weight of the passenger or determines the build of the passenger, thereby improving the usability of peripheral devices of a seat. The passenger detecting apparatus has a dielectric sensor (111) and a pressure-sensitive sensor (112) in a seat cushion (102) and detects the presence of a passenger or an object on a seat based on their outputs, or has a dielectric sensor and a pressure-sensitive sensor in the seat cushion and a dielectric sensor (113) in the back rest and an angle sensor (114) for detecting an angle defined by the seat cushion and the back rest and determines the build of a passenger based on their outputs.
摘要:
A device for controlling the current consumption of a power supply which applies a voltage to a transmission control circuit for transmitting a transmission signal with respect to a transmission line is provided. A power supply stabilizing circuit for stabilizing a voltage applied from the power supply; an amplitude detection circuit for detecting a transmission signal input from the transmission line; a switching circuit for interrupting application of a voltage from the power supply stabilizing circuit to the transmission control circuit; and a control circuit for controlling the open/closed state of the switching circuit according to the presence or absence of a transmission signal detected by the amplitude detection circuit are provided, and only when the amplitude detection circuit has detected the transmission signal, the control circuit sets the switching circuit into the closed state so as to permit a voltage to be applied to the transmission control circuit. When no transmission signal is transmitted, application of an unnecessary voltage to the transmission control circuit is interrupted, thereby reducing the current consumption.
摘要:
A terminal node (40); which includes a first bias unit (41) for biasing a first transmission line (10), out of two common transmission lines (10, 11), to a power supply potential, a second bias unit (42) for biasing a second transmission line (11) to the ground potential, and a communication control unit (43) for controlling data transmission. Another terminal node (50), which includes a communication control unit (51) is also provided. Connecting terminals (44 to 47, 52 to 55) are provided which connect the bias units (41, 42) and the communication control units (43, 51) of the terminal nodes (40, 50) to the transmission lines (10, 11) at two points for each line, and the terminal nodes (40, 50) are daisy-chain-connected to the transmission lines (10, 11) by means of the connecting terminals.
摘要:
At least two multiplex nodes (11 to 15 or 21 to 25) are connected to each other by means of a data bus (10a or 20a), at least two data buses (10a, 20a) are connected with the individual multiplex nodes (11 to 15, 21 to 25), and a gateway node (30) is connected individually to the data buses (10a, 20a). An internal memory (30d) stores data inputted through the data buses (10a, 20a) and a CPU (30a) discriminates the data inputted through the data buses (10a, 20a). The CPU (30a) discriminates data sent from one multiplex node and stores it in the internal memory (30d), and converts it into data for the other line for sending or transmits it without converting it.
摘要:
A multipath transmission system according to the present invention comprises a plurality of multiplex nodes connected to two multiplex buses. Each of the multiplex nodes is assigned to a specific apparatus, and includes a communication control circuit (LSI) for fetching multiplex signals from the apparatus and transmitting the multiplex signals to the multiplex buses. One multiplex node, out of the plurality of multiplex nodes, includes communication control circuits driver/receiver circuits, and troubleshooting driver/receiver circuits, which are connected to the multiplex buses and used for signal transfer between the buses, and a microprocessor for troubleshooting the multiplex buses and the multiplex nodes. The multiplex node relays a failure signal, corresponding to the result of troubleshooting, to the other network which suffers no trouble.
摘要:
A multiplex transmission apparatus in accordance with the present invention is interconnected with other multiplex transmission apparatuses via common transmission lines, and it is used for a multiplex transmission system which performs data transmission. The multiplex transmission apparatus comprises voltage converting circuits which detect voltages of the transmission lines, the first comparator which compares the detected voltages, the second comparator which compares one voltage of the detected voltages with a reference voltage, and the third comparator which compares the other detected voltage with a reference voltage. The comparators supply the comparison results to differential circuits, respectively, set the output of the differential circuit linked to a comparator, which is connected to a faulty line, for "L", and determine the logical sum of the outputs of the differential circuits by a logical synthesizing circuit. By applying the determined logical sum to a multiplex transmission control circuit, the apparatus makes it possible to reduce wasteful message transmission and successfully cope with faults in the transmission lines without causing delay in transmission of messages which require quick responses and without increasing the traffic volume of the transmission lines. The multiplex transmission control circuit detects signals on the transmission lines according to the comparison results of the comparators.