JPH05183562A - Multiplex transmitter - Google Patents

Abstract

PURPOSE:To simplify the system in the multiplex transmitter able to select the multiplex communication mode in which plural control units connected to a common multiplex communication line make multiplex communication via a built-in multiplex communication interface or the sleep mode in which the interface is at a halt. CONSTITUTION:Nodes A, B, C 14A, 14B, 14C are connected to 1st and 2nd transmission lines 12, 13 connected in a ring and controllers 17A, 17B, 17C, provided to each node send/receive a signal mutually through multiplex modules 15A, 15B, 15C interposed between the 1st and 2nd transmission lines 12, 13. Then start circuits 20A, 20B, 20C, to input/output a start signal used to select the operating state of the controllers 17A, 17B, 17C from the sleep mode into the multiplex communication mode are provided to the nodes A, B, C, 14A, 14B, 14C independently of the multiplex modules 15A, 15B, 15C, and the start circuits 20A, 20B, 20C are respectively connected to the 1st transmission line 12.

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, and more particularly to a multiplex communication mode in which a plurality of control units connected on a common multiplex communication line perform multiplex communication through a built-in multiplex communication interface. The present invention relates to a multiplex transmission device capable of switching between a sleep mode in which an interface is suspended.

[0002]

2. Description of the Related Art In vehicles and the like, electronic control of various controls has been promoted along with the development of electronics in recent years, and new electric components tend to be equipped in order to increase added value. In that case, generally, a control signal is transmitted by using a wire harness in which a large number of signal lines are bundled, but it is becoming difficult to secure a space for installing the wire harness as electronics are advanced.

In order to fundamentally solve such a problem, use of multiplex communication has been attempted as disclosed in, for example, Japanese Patent Laid-Open No. 62-4658. This is, for example, by providing multiple control interfaces with multiplex communication interfaces for multiplexing and transmitting and receiving data, and connecting these multiplex communication interfaces to one or two multiplex communication lines, It is intended to perform bidirectional communication between the control controllers provided in the respective control units via the multiplex communication interface. According to this, a large number of signal lines are not needed, so that the wire harness can be simplified.

On the other hand, in a moving body such as a vehicle that cannot be supplied with electric power from the outside, electricity output from a generator driven by an engine is generally supplied to an electric load. It is required to suppress power consumption in the load as much as possible. Therefore,
Also in a control unit that constitutes a multiplex transmission device in this type of mobile unit, a multiplex communication mode in which multiplex communication is performed via a multiplex communication interface provided between a multiplex communication line and a controller, for example, a multiplex communication interface A sleep mode that reduces the current consumption by providing a sleep mode is provided, and in normal times the control unit is operated in the sleep mode to reduce unnecessary power consumption and to activate the external switch for a prescribed start time. There is a system in which the operating state of the controller is switched to the multiplex communication mode in which the multiplex communication interface operates when the conditions are satisfied.

[0005]

By the way, when the control unit constituting the multiplex transmission device operates in two operation modes, that is, the multiplex communication mode and the sleep mode, as described below, Will cause another problem.

That is, in the sleep mode, since the multiplex communication interface is inactive, the individual control units constituting the system are separated from each other, and for example, one control unit switches from the sleep mode to the multiplex communication mode. Even if it is replaced, the remaining control units maintain the sleep mode, and the multiplex communication interface continues to be in the idle state, and the data link via the multiplex communication line is not established.

For such a problem, a system configuration as shown in FIG. 4, for example, has been considered. That is, in the multiplex transmission system in which a plurality of control units 1 ... 1 are connected to the multiplex communication line 2, the signal lines 4 ... 4 of the external switches 3 ... 3 connected to the respective control units 1 ... 1 are exclusively activated. The signal lines 5 are connected to each other. Therefore, when any external switch 3 is turned ON, all the control units 1 ... 1 exit from the sleep mode and shift to the multiplex communication mode, and bidirectional communication via the multiplex communication line 2 becomes possible.

However, in the above system, since the activation signal line 5 is required in addition to the multiplex communication line 2, there is a problem that the wire-saving effect due to the use of multiplex communication is impaired.

Moreover, since the start-up signal line 5 does not have a backup, if the start-up signal line 5 is broken, a serious malfunction will occur, and a problem remains in terms of system reliability.

The present invention switches between a multiplex communication mode in which a plurality of control units connected on a common multiplex communication line perform multiplex communication through a built-in multiplex communication interface, and a sleep mode in which the interface is suspended. The present invention addresses the above problems in a possible multiplex transmission device, and aims to simplify the system.

[0011]

That is, in the multiplex transmission apparatus according to claim 1 of the present application, a plurality of control units are connected on a common multiplex communication line, and controllers provided in these control units are the above-mentioned. Multiplex communication in which signals are mutually transmitted and received through an interface for multiplex communication provided between the multiplex communication line and each control unit performs multiplex transmission through the interface for multiplex communication In the mode in which the mode and the sleep mode in which the interface is inactive can be switched,
Each of the control units is provided with a start-up circuit for inputting and outputting a start-up signal for switching the operation state of the controller from the sleep mode in which the multiplex communication interface is inactive to the multiplex communication mode, independently of the multiplex communication interface. Each of the start-up circuits is connected to the multiplex communication line.

Further, a multiplex transmission device according to a second aspect of the present application is characterized in that the multiplex transmission line according to the first aspect is configured so that the multiplex communication line is formed in a ring shape.

[0013]

According to the multiplex transmission device of the present invention, the control unit is provided with the respective start circuits for inputting and outputting the start signal for starting the controller, and these start circuits are simply connected to the multiplex communication line. Because of the configuration, in the sleep mode where the interface for multiplex communication is inactive, the multiplex communication line also serves as the activation signal line, which simplifies the system without impairing the advantage of wire saving and also reduces the cost. It will be planned.

Particularly, according to the multiplex transmission device of the second aspect, since the multiplex communication line is formed in a ring shape, even if one place of the multiplex communication line is broken, the start signal propagates in the reverse direction. Therefore, the unbootable state is unlikely to occur and the reliability of the system is improved.

[0015]

EXAMPLES Examples of the present invention will be described below.

As shown in FIG. 1, in the multiplex transmission device 11 according to the embodiment, first and second transmission lines 13 formed in a ring shape.
Is provided, and the first and second transmission lines 1 are provided.
Nodes A, B, and C that form a control unit are shown at 2 and 13.
14 _A , 14 _B and 14 _C are connected respectively.

The node _A 14 _A is provided with a multiplex module 15 _A as an interface for multiplex communication, and is connected to the controller 17 _A via a bidirectional bus 16 _A. The first transmission line 12 is connected to the first transmission line 12.
The communication line 18 _A and the second communication line 19 _A connected to the second transmission line 13 are connected to the multiple module 15 _A , respectively.

Further, the starting circuit 20 _{A according} to this embodiment is provided in the node _A 14 _A independently of the multiple module 15 _A. The starting circuit 20 _A has an NPN type input transistor 21 _A for inputting a starting signal and a PNP type output transistor 22 _A for outputting a starting signal. The emitter side of the input transistor 21 _A is body-grounded, and the interrupt side input terminal 23 _A of the controller 17 _A is connected to the collector side via an input signal line 24 _A. And this input transistor 21 _A
A start signal line 25 _A branched from the first communication line 18 _A is connected to the base side of the. On the other hand, the power supply voltage is applied to the emitter side of the output transistor 22 _A , and the activation signal output terminal 26 _A provided in the controller 17 _A is connected to the base side via the output signal line 27 _A. There is. And this output transistor 22 _A
The start signal line 25 _A is connected to the collector side of the.

An external switch 28 is connected to the controller 17 _A.

[0020] Here, to describe the basic operation state of the controller 17 _A, with the controller 17 _A in the normal state to operate the node A14 _A by resting the operation of the multi-module 15 _A in sleep mode When the external switch 28 is turned on or a predetermined activation condition such as the activation signal being input to the interrupt input terminal 23 _A is satisfied, the multiple module 15 _A is activated to set the node _A 14 _A in the multiple communication mode. It is designed to work.

The node B 14 _B has the same structure as the node _A 14 _A, and has the multiple module 15 _B connected to the controller 17 _B via the bidirectional bus 16 _B, and the multiple module 15 _B. The input transistor 2 of the starting circuit 20 _B provided independently of
A start signal line 25 _B branched from a first signal line 18 _B connecting the multiplex module 15 _B and the first transmission line 12 is connected to the base side of 1 _B. The interrupt input terminal 23 _B of the controller 17 _B is connected to the collector side of the input transistor 21 _B via the input signal line 24 _B. An output signal line 27 _B connected to the activation signal output terminal 26 _B of the controller 17 _B is connected to the base side of the output transistor 22 _B , and the activation signal line 25 is connected to the collector side of the transistor 22 _{B. B} is connected.

[0022] Then, the controller 17 _B in the Node B14 _B, an external switch 29 and the actuator 30 are connected.

Further, the node will be C14 _C, and has a multi-module 15 _C which is connected to the controller 17 _C via a bidirectional bus 16 _C, the starting circuit is provided independently of this multiplexing module 15 _C 20 the base of the input transistor 21 _C and _C, multiple module 15 _C and starting signal line 25 _C branched from the first communication line 18 _C connecting the first transmission line 12 is connected. The interrupt input terminal 23 _C of the controller 17 _C is connected to the collector side of the input transistor 21 _C via the input signal line 24 _C. An output signal line 27 _C connected to the start signal output terminal 26 _C of the controller 17 _C is connected to the base side of the output transistor 22 _C , and the start signal line 25 is connected to the collector side of the transistor 22 _{C. C} is connected.

The controller 17 _C in the node C 14 _C has a sensor 31 and an actuator 32.
And are connected.

Next, the transition operation from the sleep mode to the multiplex communication mode in the multiplex transmission device 1 will be described. This transition operation is performed as follows according to the operation procedure shown in the flowchart of FIG.

That is, first, in step S1, the node A1
4 _A is performed is determined whether satisfies a predetermined start condition, the controller 17 _A of when the determination is YES node A14 _A together with activating the node A14 _A activates multiple module 15 _A , _A start signal is output from the start signal output terminal 26 _A to turn on the output transistor 22 _A of the start circuit 20 _A , so that the node B14 _B and the node C1 are turned on.
4 _C is activated (steps S2 to S4). Then, the controller 17 _A determines in step S5 whether or not the predetermined waiting time T ₀ has elapsed. When it is determined that the standby time T ₀ has elapsed, the controller 17 _A proceeds to step S6 and passes through the multiplex module 15 _A. Then, the transmission request frame is output, and then in step S7, the mode shifts to the multiplex communication mode.

On the other hand, in step S1 described above, the node A
If it is determined that 14 _A does not satisfy the predetermined start condition, then in step S8 it is determined whether or not the node B 14 _B satisfies the start condition, and if YES is determined, the node B The controller 17 _{B of} B14 _B activates the multiple module 15 _B to activate the node B14 _B , and outputs an activation signal from the activation signal output terminal 26 _B to turn on the output transistor 22 _B of the activation circuit 20 _B. activating the node A14 _a and node C14 _C (step S9 to S11). Then, the controller 17
_B, it is determined whether the waiting time T ₀ has elapsed at step S12, outputs the transmission request frame over multiple module 15 _B proceeds to step S13 when it is determined that the standby time T ₀ has elapsed It is like this.

Further, when it is determined in step S8 that the node B14 _B also does not satisfy the activation condition, it is determined in step S14 whether or not the node C14 _C satisfies the activation condition. , with YES if it is determined that the node C14 _C controller 17 _C activates the node C14 _C activates multiple module 15 _C, the starting circuit 20 _C output by outputting a start signal from the start signal output terminal 26 _C The transistor 22 _C is turned on to activate the node B14 _B and the node C14 _C (steps S15 to S17). Then, the controller 17
_C, it is determined whether the waiting time T ₀ has elapsed at step S18, outputs the transmission request frame over multiple module 15 _C proceeds to Step S19 when it is determined that the standby time T ₀ has elapsed ..

Next, the operation of this embodiment when the node A14 _A is set as the starting node will be described with reference to the time chart of FIG.

That is, as shown in FIG. 3A, assuming that the external switch 28 is turned on at time t ₁ , the controller 17 _A of the node _A 14 _A which has input the signal outputs the activation pulse from the activation signal output terminal 26 _A. Is output. Activation circuit 20 _A This activation pulse via the output signal line 27 _A
Is applied to the base of the output transistor 22 _A, FIG output transistor 22 _A, as shown in (b) is turned on, the voltage outputted to the start signal line 25 _A which is connected to the collector side first communication First transmission line 1 via line 18 _A
2 is transmitted. Therefore, as shown in FIG. 7C, the first transmission line 12 becomes high level, and the base side voltage of the input transistors 21 _B and 21 _C of the starter circuits 20 _B and 20 _{C at} the nodes B14 _B and C14 _{C also} becomes high. As a result, the input transistors 21 _B and 21 _C are turned on. This allows node B
Controller 17 _{B at} 14 _B and node C 14 _C ,
The interrupt input terminals 23 _B and 23 _{C of} 17 _C respectively fall to the ground to enable the interrupt, and the node B14 _B and the node C14 _C are activated from the dormant state as shown in (d) and (e) of FIG. It will transition to the state.

Then, as shown in FIG. 3C, at the time t ₃ when a predetermined waiting time T ₀ has elapsed from the time t ₂ when the output transistor 22 _A provided in the node _A 14 _A is turned on, the first transmission line so that the transmission request frame over multiple module 15 _a at node A14 _a is outputted to the 12.

[0032] Then, in this embodiment, first node A as shown in FIG. _{1, B, C14 A, 14} B, 14 start circuit provided in the _{C 20 A, 20 B, 20} C are connected since the first transmission line 12 is formed in an annular shape, if the node B14 _B and node C14 points even though a break in P between _{C, the} starting circuit 20 _B of the nodes B14 _B and node C14 _C, Each input transistor 21 at 20 _C
The conduction state between _B and 21 _C and the first transmission line 12 is maintained, and it is possible to prevent the start failure.

Further, the nodes _{A to} C14 _A , 14 _B , 1
When the controllers 17 _A , 17 _B , and 17 _C in 4 _C are ready for the sleep state, the controllers 17 _A , 17 _B , and 17 _C send a data frame indicating the preparation completion to the first and second transmission lines via the multiple modules 15 _A , 15 _B , and 15 _C. 12 and 13, when all the nodes are ready for the sleep state, the multiple communication mode is switched to the sleep mode.

The number of nodes is not limited to three.

[0035]

As described above, according to the multiplex transmission device of the first aspect of the present invention, the control unit is provided with the start-up circuit for inputting and outputting the start-up signal for starting up the controller, and these start-up circuits are multiplexed. Since the configuration is only connected to the line, in the sleep mode in which the interface for multiplex communication is inactive, the multiplex communication line also serves as the activation signal line, which simplifies the system without compromising the advantage of wire saving. It also means that costs can be reduced.

In particular, according to the multiplex transmission device of the second aspect, since the multiplex communication line is formed in a ring, even if one place of the multiplex communication line is broken, the start signal propagates in the reverse direction. Therefore, the unbootable state is unlikely to occur and the reliability of the system is improved.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a system configuration of a multiplex transmission device according to an embodiment.

FIG. 2 is a flowchart showing a procedure of a transition operation from a sleep mode to a multiplex communication mode.

FIG. 3 is a time chart showing the operation of the embodiment.

FIG. 4 is an explanatory diagram of a conventional problem.

[Explanation of symbols]

11 Multiplex Transmission Device 12 First Transmission Line 13 Second Transmission Line 14 _A Node A 14 _B Node B 14 _C Node C 15 _A , 15 _B , 15 _C Multiplex Module 17 _A , 17 _B , 17 _C Controller 20 _A , 20 _B , 20 _C start circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toshinaga Tokunaga No. 3 Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Osamu Dohira No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Within the corporation

Claims (2)

[Claims] 1. A plurality of control units are connected on a common multiplex communication line, and controllers provided in these control units are connected via a multiplex communication interface provided between the control units and the multiplex communication line. Multiplex transmission configured to exchange signals with each other and capable of switching between a multiplex communication mode in which each control unit performs multiplex transmission through the multiplex communication interface and a sleep mode in which the interface is suspended. In the device, each of the control units has an activation circuit for inputting and outputting an activation signal for switching the operating state of the controller from the sleep mode in which the multiple communication interface is inactive to the multiple communication mode, independently of the multiple communication interface. These start circuits are connected to the multiplex communication line. A multiplex transmission device characterized by being continued. 2. The multiplex transmission device according to claim 1, wherein the multiplex communication line is formed in a ring shape.