JP3372569B2 - Multiplex transmission equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex transmission apparatus for transmitting a signal through a multiplex communication line. 2. Description of the Related Art In transmitting a signal for controlling electric components mounted on a vehicle, for example, an air conditioner, an audio device, etc., a multiplex communication line is used to suppress enlargement and complication of a harness. It has been proposed. For example, Japanese Patent Laying-Open No. 62-4568 discloses a multiplex communication system in which an operation switch is connected to output devices such as various display devices by such a multiplex communication line to perform control. [0003] When an apparatus using such a multiplex communication system is mounted on, for example, an automobile,
In the stopped state of the engine, the electric power depends on the battery power source, so it is necessary to reduce the power consumption as much as possible. For this reason, when the device is actually stopped operating, from the viewpoint of suppressing the power consumption of the device, only the minimum necessary power supply is performed so as to be able to respond promptly when a start-up request is made, It has been proposed to suspend power supply to unnecessary parts for the time being to give a so-called sleep state. However, in a system that includes a plurality of components, that is, a plurality of nodes and performs multiplex communication among each other, when each node sleeps separately, another node that should receive data transmitted from one node should be received. When the device is in the sleep state, there is a concern that a situation in which the process is not properly performed may occur, and control of the entire device may not be obtained, which may hinder operation. In view of this point, it has been proposed that the constituent nodes of the multiplex transmission system, while confirming each other, shift to the sleep state all at once after all the constituent nodes enter the sleep state. But,
Even in this case, if any of the constituent nodes does not operate properly due to a failure or the like, it is not possible to confirm whether the system is ready for the sleep state, and the sleep control may not function. [0004] The present invention is constructed from such a viewpoint. In a multiplex transmission apparatus having a plurality of nodes, even if an abnormality occurs in a constituent node, sleep control is appropriately performed to ensure the sleep control. An object of the present invention is to provide a multiplex transmission device capable of reducing power consumption. [0005] In order to solve the above problems, the present invention is configured as follows. A multiplex transmission device according to the present invention determines a plurality of nodes that transmit and receive signals between a plurality of nodes via a multiplex communication line, and determines whether a transition to a sleep state of the node provided in each of the nodes is possible. A sleep determination unit that is provided in each of the nodes and generates a sleep signal indicating that the node can shift to the sleep state when the determination unit determines that the transition to the sleep state is possible. Sleep transmitting means for transmitting a sleep signal to all nodes, monitoring means provided at each node to determine whether communication is possible via a multiplex communication line, and transition to the sleep state of the node provided at each node Permission means for permitting
The permitting means determines that it is possible to shift to the sleep state by its own sleep determining means, and receives a sleep signal from all nodes determined to be communicable by the monitoring means, and Is permitted to shift to a sleep state. According to the present invention, a multiplex transmission apparatus including a plurality of communication nodes confirms the state of each constituent node in a normal operation state (wake-up state) and sleeps. It is determined whether the process can be shifted to. For this reason, each of the constituent nodes has a determination unit for determining whether or not the transition to the sleep state is possible. When each node determines by this determination that it is ready for the transition to the sleep state, it outputs a sleep signal that inquires of other nodes whether the state for the sleep state is ready. That is, this sleep signal means a signal for inquiring that the state of the other node is ready for the sleep state, and a signal declaring that the other node is ready for the sleep state. means. When the node that has received the sleep signal is ready for itself, it receives an approval signal (A
(NC signal). Then, the ANC signals of all the other nodes are checked, and when the sleep signals are received from all the nodes thereafter, the nodes shift to the sleep state. The other nodes perform the same operation to enter the sleep state, so that the multiplex transmission apparatuses simultaneously shift to the sleep state. In this case, if there is a node that does not respond to the inquiry signal for some reason, that is, there is no ANC signal, the sleep signal is received from all the other nodes even if the sleep signal from that node is not received. If so, the permission unit permits the node to shift to the sleep state. By controlling in this way, even if some abnormality occurs in the wake-up state and there is a node that cannot send a sleep signal, the rest of the nodes are put into the sleep state by shifting the rest of the system to the sleep state. The power consumption can be effectively reduced. An embodiment of the present invention will be described below with reference to the drawings. Referring to FIG. 1, a multiplex transmission apparatus 1 according to the present example includes an A node 2, a B node 3, and a C node 4. These nodes 2, 3, and 4 have the same hardware configuration, and only the internal configuration of A node 2 is schematically shown. The A node 2, the B node 3, and the C node 4 process a multiplex communication signal with a microcomputer 5 having a microprocessor and a memory and other nodes and input the signal to the microcomputer, or receive signals from the microcomputer and perform other processing. A multiplex communication module 6 for transmitting to a node is provided. Also, each node 2, 3, 4
Are connected to each other by a multiplex communication line 7 so that communication is possible. As shown in FIG. 2, for example, as shown in FIG. 2, the function data constituting the contents of the control signal transmitted from the A node transmitted through the multiplex communication line 7 includes a start message 8, a signal priority 9, a signal type 10, a transmission data 11, data abnormality check 12, data end message 13, approval 14
And information such as the end message 15. Also, a wake-up switch 16 (for example, an ignition switch) that switches the apparatus from a stopped state, ie, a sleep state to a normal operation state, ie, a wake-up state, is connected to the A node 2. Referring to FIG. 3, there is shown a flowchart showing the contents of the operation of the multiplex transmission apparatus of the present embodiment. The control is performed by the microcomputer 5 of each node. The microcomputer 5 first determines whether or not a condition for putting the node into a wake-up state is established. When a signal for wake-up state is input, the microcomputer 5 sets the wake-up state accordingly, Is performed. Next, it is determined whether or not the node can shift to the sleep state. If the transition to the sleep state is possible, the sleep signal is transmitted to another node. Next, it is checked whether or not a wake-up signal has been input. If the wake-up signal has not been input and it is possible to shift to the sleep state, it is determined whether or not all sleep signals from other nodes have been input. If it has been input, the transition to the sleep state is permitted and the transition is made. Otherwise, the AN of the node that has not received the sleep signal
It is determined whether a C signal, that is, a signal indicating that the sleep signal has been received, cannot be confirmed. If the ANC signal of the other node can be confirmed, it waits for a sleep signal from that node. This state indicates that the node is not yet ready for the sleep state. Thereafter, by receiving a sleep signal from the node, the apparatus shifts to a sleep state when all sleep signals are received. If the ANC signal cannot be confirmed, it is determined that the node is in an abnormal state, and a transition to the sleep state is performed. According to the present invention, even when some of the constituent nodes of the multiplex transmission apparatus have some trouble, a way is provided to shift the apparatus to the sleep state only by the remaining constituent nodes. Thus, power consumption can be effectively reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a device configuration of a multiplex transmission device according to one embodiment of the present invention; FIG. 2 is an explanatory diagram showing the contents of function data; FIG. It is a flowchart which shows the content of control. [Description of Signs] 1 Multiplex transmission device, 2, 3, 4, node, 5 microcomputer, 6 multiplex module, 7 multiplex communication line.

Continuation of the front page (72) Inventor Yasuhiko Kurata 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Naldec Co., Ltd. (56) References JP-A-5-58233 (JP, A) JP-A-6-122350 ( JP, A) JP-A-5-58234 (JP, A) JP-A-5-58232 (JP, A) JP-A-6-62021 (JP, A) JP-A-5-181796 (JP, A) JP-A-4-345239 (JP, A) JP-A-5-236560 (JP, A) JP-A-5-193427 (JP, A) JP-A-3-25046 (JP, A) JP-A-5-16746 (JP , A) JP-A-5-175964 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04Q 9/00 H04L 12/00

Claims (1)

(57) [Claim 1] A plurality of nodes that transmit and receive signals between a plurality of nodes via a multiplex communication line and a transition to a sleep state of each node provided in each of the nodes. Sleep determining means for determining whether or not the node can be shifted to a sleep state provided by each of the nodes when the determining means determines that the node can be shifted to the sleep state And a sleep transmitting means for transmitting a sleep signal to all other nodes, a monitoring means provided at each node to determine whether communication is possible via a multiplex communication line, and a Permission means for permitting the transition to the sleep state,
The permitting means is configured to, when it is determined by the own sleep determining means that the transition to the sleep state is possible, receive a sleep signal from all nodes determined to be communicable by the monitoring means, and A multiplex transmission apparatus that permits a transition to a sleep state.