JPH0638276A - Multiplex transmitter - Google Patents

Abstract

PURPOSE:To save power consumption effectively by permitting a node to the transit to the sleep state when a sleep signal is received from all other nodes even when a mode has a fault. CONSTITUTION:A microcomputer 5 of each node at first discriminates whether or not conditions of setting the node to a wake-up state are finished and sets the node to the wakeup state accordingly when a signal to set the wake-up state is received and implements a prescribed operation. Then the microcomputer discriminates whether or not the node is transited to the sleep state. When the transit to the sleep state is available, the microcomputer sends the sleep signal to other nodes, When the transit to the sleep state is available and the sleep signal is received from all other nodes, the microcomputer permits the transit to the sleep state and allows the node to the sleep state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex transmission device for transmitting signals via multiplex communication lines.

[0002]

2. Description of the Related Art It has been proposed to use a multiple communication line in order to suppress enlargement and complication of a harness when transmitting a signal for controlling an electric component mounted on an automobile, such as an air conditioner or an audio device. Has been done. For example, Japanese Unexamined Patent Publication No. 62-4568 discloses a multiplex communication system in which an operation switch and an output device such as various display devices are connected 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,
When the engine is stopped, the electric power depends on the battery power source, so it is necessary to reduce the electric power consumption as much as possible. Therefore, when the device is virtually stopped, from the viewpoint of suppressing the power consumption of the device, when the startup request is made, while supplying only the minimum necessary power so that it can respond promptly, It has been proposed to stop the power supply to unnecessary portions for the time being to give a so-called sleep state. However, in a system that has multiple components, that is, multiple nodes, and that multiple nodes communicate with each other, when each node sleeps in different states, other nodes that should receive the data transmitted from one node There is a concern that the device may not be properly processed when the device is in the sleep state, and the control of the entire device may be lost, which may hinder the operation. In view of this point, it is proposed that the constituent nodes of the multiplex transmission system shift to the sleep state all at once after all the constituent nodes enter the sleep state while confirming each other. But,
Even in this case, if some of the constituent nodes do not operate properly due to a failure or the like, it may not be possible to confirm whether or not the system can be put into the sleep state, and the sleep control may not function.

The present invention is configured from such a point of view, and in a multiplex transmission apparatus having a plurality of nodes, even if an abnormality occurs in a constituent node, the sleep control is appropriately performed to ensure the reliability. 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 perform signal transmission / reception between a plurality of nodes via multiplex communication lines, and determine whether or not the nodes are provided in each of the nodes and can shift to a sleep state. And a sleep determination unit provided in each of the nodes, and when the determination unit determines that the transition to the sleep state is possible, generates a sleep signal indicating that the node can transition to the sleep state. Sleep transmission means for sending a sleep signal to all nodes, monitoring means provided in each node for judging whether or not communication is possible via a multiplex communication line, and transition provided in each of the nodes to a sleep state of the node And permission means for permitting
When the permitting means receives the sleep signals from all the nodes determined to be communicable by the monitoring means when the sleep determining means determines that the sleep state can be entered, the node concerned Is permitted to shift to the sleep state.

[0006]

According to the present invention, a multiplex transmission apparatus including a plurality of communication nodes can check the state of each constituent node in a normal operating state (wakeup state) and shift to a sleep state. Determine whether or not. Therefore, each of the constituent nodes is provided with a determination means for determining whether or not the transition to the sleep state is possible. Then, when each node determines that the transition to the sleep state is completed by this determination, it outputs a sleep signal for inquiring to other nodes whether or not the transition to the sleep state is completed. In other words, this sleep signal means a signal inquiring that the state of the other node is ready for the sleep state, and also a signal that declares that the other node is ready for its own sleep state. means. When the node that received the sleep signal is ready for itself, it sends the acknowledge signal (A
(NC signal) is output to respond. Then, when the ANC signals of all the other nodes are confirmed and then the sleep signals from all the nodes are received, the node shifts to the sleep state. Since the other nodes perform the same operation and enter the sleep state, the multiplex transmission apparatus simultaneously shifts to the sleep state.

In this case, if there is a node that does not have the ANC signal in response to the inquiry signal for some reason, the sleep signal is received from all the other nodes even if the sleep signal from that node is not received. If so, the permitting unit permits the node to shift to the sleep state. By controlling in this way, even if there is a node that cannot send the sleep signal due to some abnormality in the wake-up state, the rest of the nodes are put into the sleep state and the entire system is put into the sleep state. The power consumption can be effectively reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, the multiplex transmission apparatus 1 according to this example includes an A node 2, a B node 2 and a C node 3. These nodes 2, 3, 4 have the same hardware configuration, and the internal configuration of only the A node 2 is schematically shown. The A node 2, the B node 3, and the C node 4 process a multiplexed communication signal with the microcomputer 5 having a microprocessor and a memory and other nodes and input the signals to the microcomputer or receive signals from the microcomputer to receive other signals. It comprises a multiplex communication module 6 for transmitting to a node. In addition, each node 2, 3, 4
Are connected to each other by a multiplex communication line 7 and can communicate with each other.

As shown in FIG. 2, for example, as shown in FIG. 2, the function data constituting the content of the control signal transmitted from the A node by the multiplex communication line 7 includes a start message 8, a signal priority 9, a signal type 10, and transmission data. 11, data abnormality check 12, data end message 13, approval 14
And the end message 15 and other information. Further, a wakeup switch 16 (for example, an ignition switch) that effectively changes the apparatus from a stopped state, that is, a sleep state to a normal operating state, that is, a wakeup 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 this example. The control is performed by the microcomputer 5 of each node. The microcomputer 5 first determines whether or not a condition for bringing the node into the wake-up state is established, and when a signal for entering the wake-up state is input, sets the wake-up state accordingly and performs a predetermined operation. To perform. Next, it is determined whether the node can shift to the sleep state. When the transition to the sleep state is possible, the sleep signal is transmitted to another node. Next, it is confirmed whether or not a wakeup signal is input thereafter. If the wake-up signal is not input and the transition to the sleep state is possible, it is determined whether or not all sleep signals from other nodes are input. When it is input, the transition to the sleep state is permitted and the transition is made. Otherwise, the AN of the node not receiving the sleep signal
It is determined whether a C signal, that is, a reply signal that the sleep signal is received cannot be confirmed. When the ANC signal of the other node can be confirmed, the sleep signal from the node is awaited. This state indicates that the node is not yet ready for sleep.

After that, by receiving the sleep signal from the node, when all the sleep signals are received, the sleep state is entered. When the ANC signal cannot be confirmed, it is determined that the node is in some abnormal state, and the transition to the sleep state is performed.

[0012]

According to the present invention, even if some abnormality occurs in some of the constituent nodes of the multiplex transmission device, the rest of the constituent nodes provide a way to shift the device to the sleep state. Power consumption can be effectively reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a device configuration of a multiplex transmission device according to an embodiment of the present invention,

FIG. 2 is an explanatory diagram showing the contents of functional data,

FIG. 3 is a flowchart showing the content of control at a node.

[Explanation of symbols]

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 Prefecture Nardeck Co., Ltd.

Claims (1)

[Claims] 1. A plurality of nodes for transmitting and receiving a signal between a plurality of nodes via a multiplex communication line, and a sleep determining means provided in each of the nodes for determining whether or not the node can shift to a sleep state. And a sleep signal indicating that the node can be shifted to the sleep state is generated when it is determined by the determination means that the node is provided to each of the nodes, and all other nodes are generated. Sleep transmitting means for sending a sleep signal, monitoring means provided in each node for judging whether or not communication is possible via a multiplex communication line, and permission provided for each node for permitting the node to shift to a sleep state And means,
When the permitting means receives the sleep signals from all the nodes determined to be communicable by the monitoring means when the sleep determining means determines that the sleep state can be entered, the node concerned A multiplex transmission device characterized by permitting a transition to a sleep state of.