JP3281472B2 - Multiplex transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to transmission of control information to a communication line for multiplex transmission of a plurality of types of control information, acquisition of control information from a communication line, or transmission of control information to a communication line. The present invention relates to a multiplex transmission apparatus configured by connecting a plurality of node units for transmitting a control signal and transmitting control information from a communication line.

[0002]

2. Description of the Related Art In a vehicle, wirings, connectors, and electronic controls provided in the vehicle are increased with the increase in the number of electric components or control systems to be equipped and the progress of computerization of various electric components or control systems. The number of devices has increased significantly, which has led to an increase in the size and weight of wire harnesses attached to vehicle bodies. And the larger wire harness is
The installation space of the harness to the vehicle body will be limited, and the flexibility of the wire / harness will be reduced, leading to a reduction in the efficiency of the assembling work.
An increase in the weight of the wire harness directly leads to an increase in the weight of the vehicle.

In order to reduce the number of wirings, connectors and electronic control units in a vehicle, for example, Japanese Patent Laid-Open No.
As disclosed in JP-A-16845, a common communication line is provided for multiplexing and transmitting a plurality of types of digital control information for controlling operations of various electric components, control systems, and the like mounted on a vehicle. At the same time, a plurality of nodes for transmitting digital control information or taking in digital control information are connected to the communication line, and various electric components and control systems mounted on the vehicle are appropriately connected to the plurality of nodes. It has been proposed to construct a multiplex communication mechanism configured by using a vehicle in a vehicle.

In a multiplex communication mechanism constructed in a vehicle as described above, for example, multiplexed digital control information is transmitted through a signal transmission line formed by a wire harness provided in a vehicle body. A communication line is formed,
Each of the plurality of node units connected to the communication line has a signal generation unit such as various sensors and switches, and
Actuating parts such as various lamps, actuators, and motors provided in each part of the vehicle are grouped and connected. A node unit to which such a signal generating unit or an operating unit is connected is a communication unit connected to a communication line, and
A configuration including an input / output processing unit connected to a signal generation unit or an operation unit, or, in addition to a communication unit and an input / output processing unit, interposed therebetween, for example,
The input / output processing unit or the information in which the input / output processing unit and the arithmetic control unit form digital control information based on a signal from the signal generation unit. The communication unit transmits digital control information formed by the information forming unit to the communication line, or the communication unit fetches digital control information selected from the communication line to form the arithmetic control unit and the input unit. Both the output processing unit or the input / output processing unit forms an operation control signal based on the digital control information captured through the communication unit, and supplies the operation control signal to the connected operation unit so that the operation of the operation unit is controlled. Operation. The digital control information multiplexed and transmitted by the communication line is, for example, each represented by a pulse code modulation (PCM) signal, and is provided with a non-return signal.
It shall take the form of an NRZ modulated carrier signal obtained by two-zero (NRZ) modulation.

In such a vehicle, a plurality of nodes for transmitting digital control information to a communication line, taking in digital control information from a communication line, or transmitting digital control information and taking in digital control information are connected. In the multiplex communication mechanism constructed and constructed, digital control information transmitted from each node unit to a communication line and taken in by a predetermined node unit is used, for example, in a data frame unit to facilitate its handling. Is formed. The data frame unit is a group of code data configured to follow a preset data format with a predetermined total number of bits.

When the data frame unit is transmitted from each node unit to the communication line, if the data frame unit is simultaneously transmitted to the communication line from each of the two or more node units, each data frame unit is formed. A situation in which a collision of digital control information occurs is copied. Therefore, each data frame unit is formed by arranging prioritized data indicating priorities corresponding to the contents of the digital control information prior to the digital control information, whereby two or more node units are formed. In the case where the data frame unit is simultaneously transmitted to the communication line from each of the nodes, when each node unit transmits the priority data in the data frame unit from each,
The priority data in the data frame unit transmitted by itself is compared with the priority data in the data frame unit transmitted by another node unit, and the priority indicated by the priority data in the data frame unit transmitted by itself is determined by another node. When the priority data in the data frame unit transmitted by the unit is higher than the expressed priority, the digital control information is transmitted following the transmission of the priority data, while the priority data in the data frame unit transmitted by itself is transmitted. If the priority represented by the priority data in the data frame unit transmitted by another node unit is lower than the priority represented by the data, the transmission of the digital control information following the transmission of the priority data is stopped. Perform the operation And so, it is made to avoid collisions of the digital control information from two or more nodes part of the communication line has been proposed.

[0007]

As described above, the data frame unit transmitted from each node unit to the communication line is:
Under a multiplex communication system that adopts a system in which digital control information is formed by adding priority code data, conventionally, each data frame unit includes:
It does not include code data representing the node part where the data frame unit was formed and transmitted to the communication line. Therefore, in a node unit that has received a predetermined data frame unit from a communication line, it is unknown which node unit sent the data frame unit. Therefore, for example, when the data frame unit taken in from a communication line in a certain node unit is not normal, the node unit in which the abnormal data frame unit is transmitted in order to quickly solve the abnormal situation. Is desirably specified immediately, but from the abnormal data frame unit, there is an inconvenience that it is not possible to know the node unit from which the transmission was made.

In view of the above, the present invention provides a communication line in which a plurality of types of digital control information are multiplexed and transmitted, and is connected to the communication line to form a communication line in data frame units formed by the digital control information. Data frame unit from the communication line
Alternatively, a predetermined communication capability is reduced under the condition that a plurality of nodes are connected to perform transmission of a data frame unit formed by digital control information to a communication line and acquisition of a data frame unit from the communication line. In each node unit, the number of constituent bits in the data frame unit is significantly increased in which node unit the data frame unit fetched from the communication line is transmitted to the communication line. It is another object of the present invention to provide a multiplex transmission device that can be easily detected.

[0009]

In order to achieve the above object, a multiplex transmission apparatus according to the present invention comprises a communication line through which a plurality of types of digital control information are multiplexed and transmitted, and each of the communication lines is connected to the communication line. An information forming unit for forming digital control information; and a plurality of nodes each including a communication unit for transmitting digital control information formed by the information to a communication line. The information forming unit converts the digital control information formed by the first code data representing the priority of the information and the node code to which the information forming unit belongs into a second code having a predetermined priority. And data comprising priority related code data comprising:

[0010]

In the multiplex transmission apparatus according to the present invention configured as described above, digital control information is transmitted from each node unit to a communication line in the form of, for example, a data frame unit. In this case, a data frame unit based on digital control information is formed by the information forming unit incorporated in each node unit as a digital control information to which priority code data is added, and code data relating to the priority is stored in the information. The first code data representing the priority order of the information forming unit and the node unit to which the information forming unit belongs, and the second code unit in which the priority order is determined in advance.
And the code data of Thus, in the node unit that has taken in the data frame unit transmitted to the communication line, the data frame unit is transmitted from any node unit based on the code data related to the priority included in the taken data frame unit. Can be easily detected if necessary. In addition, a situation in which the number of constituent bits in a data frame unit is particularly increased due to this need not be imitated.

[0011]

FIG. 2 shows an example of a multiplex transmission apparatus according to the present invention applied to a vehicle.

In FIG. 2, two multiplex communication line systems are formed on a vehicle body indicated by a dashed line with communication lines indicated by a solid line and a broken line, respectively.
The communication line indicated by the solid line is, for example, a high-speed communication line 1 using a twisted pair shield line.
1 and the communication line indicated by the dashed line is
For example, the low-speed communication line 12 uses a twisted pair line. Each of the high-speed communication line 11 and the low-speed communication line 12 is disposed inside the vehicle body,
A plurality of node parts arranged in each part of the vehicle body are connected to them.

The plurality of nodes are connected to the high-speed communication line 11 and are high-speed communication line-related nodes, such as an engine node 15, a main fuse node 16, an anti-skid brake system (ABS) node 17, and a four-wheel drive system ( 4WS) node 18, rear left node 19, rear right node 20, and low speed communication line related nodes connected to low speed communication line 12, such as front right node 21, front left node 22, instrument panel node 23, The cowl left node 24, the center console node 25, the accessory switch node 26, the front left door node 27, the rear left door node 28, the front right door node 29, the rear right door node 30, the tail node 31, and the column node 32 are connected at high speed. Line 11 and the low-speed communication line 12
It is a high-speed communication line node and a low-speed communication line node connected to both of them, and includes a cowl light node 33 and a meter node 34 that function as a gateway. Although not shown in FIG. 2, each of the plurality of nodes has various lamp driving units, actuators, motors and other operating units, and various sensors and switches and other signal generating units. Are grouped and connected.

Each of the high-speed communication line nodes connected to the high-speed communication line 11 among the plurality of nodes forms high-speed digital control information based on a signal from a signal generator connected to each of the nodes. To the high-speed communication line 11, or fetches high-speed digital control information selected from the high-speed communication line 11, forms a control signal based on the fetched high-speed digital control information, and connects the control signal to each of them. The operation of supplying the power to the operation unit and controlling the operation of the operation unit is performed. Similarly, each of the low-speed communication line-related nodes connected to the low-speed communication line 12 among the plurality of nodes forms low-speed digital control information based on a signal from a signal generation unit connected to each of the nodes.
Sending it to the low-speed communication line 12, or
The selected low-speed digital control information is fetched from the low-speed communication line 12, a control signal based on the fetched low-speed digital control information is formed, and the control signal is supplied to each of the operation units connected thereto to control the operation of the operation unit. Perform the operation. Also, the cowl light node 33 which is a high-speed communication line node connected to both the high-speed communication line 11 and the low-speed communication line 12 and is also a low-speed communication line node.
And each of the meter nodes 34 sends out high-speed digital control information to the high-speed communication line 11 or fetches high-speed digital control information from the high-speed communication line 11,
It sends both the low-speed digital control information to the low-speed communication line 12 and the low-speed digital control information from the low-speed communication line 12.

Each of the high-speed communication line node and the low-speed communication line node includes a multiplex communication unit having a communication input / output terminal connected to the high-speed communication line 11 or the low-speed communication line 12 through a bidirectional drop-in line, and a data bus. A non-computation control type connected to the multiplex communication unit and including an input / output processing unit having an input / output terminal connected to an operated control unit or a signal generation unit, or a high-speed communication line 11 or low-speed communication line 1
2, a multiplex communication unit connected to a communication input / output terminal through a bidirectional drop-in line, an arithmetic control unit connected to the multiplex communication unit through a data bus, and an arithmetic control unit connected to the arithmetic control unit through a data bus. It is of an arithmetic control type having a built-in operation control section or an input / output processing section having a signal generation section connected to an output terminal. In the non-operation control type node, the input / output processing unit includes an information forming unit that forms high-speed or low-speed digital control information based on a signal from a signal generation unit connected thereto, and a multiplex communication unit. Constitutes a communication unit for transmitting the high-speed or low-speed digital control information formed by the information forming unit to the high-speed communication line 11 or the low-speed communication line 12, respectively. An output processing unit and an arithmetic control unit, an information forming unit for forming high-speed or low-speed digital control information based on a signal from a signal generating unit connected to the input / output processing unit; and a multiplex communication unit, Communication units for transmitting the high-speed or low-speed digital control information formed by the above to the high-speed communication line 11 or the low-speed communication line 12, respectively. .

For example, FIG. 1 shows an example of a low-speed communication line system node connected to the low-speed communication line 12. In the example shown in FIG. 1, as the low-speed communication line system node,
A front light node 21, an instrument panel node 23, and a node 35 connected to another low-speed communication line 12 are shown.

The front light node 21 shown in FIG.
A multiplex communication unit 42 in which a communication input / output terminal is connected to the low-speed communication line 12 through a bidirectional drop line 41;
The arithmetic control unit 44 is connected to the multiplex communication unit 42 via a data bus 43, and the input / output processing unit 46 is connected to the arithmetic control unit 44 via a data bus 45. The input / output terminals of the input / output processing unit 46 are operated control units in the vehicle, for example, an actuator 47 for a retractable head lamp, a lamp driving unit 48, and other components not shown. And a switch 49 for detecting a bonnet open state, which is not shown, and the like, which are signal generators in the vehicle.

The instrument panel node 23
A multiplex communication section 52 having a communication input / output terminal connected to the low-speed communication line 12 through the bidirectional drop-in line 41;
An arithmetic control unit 54 connected to the multiplex communication unit 52 via a data bus 53 and an input / output processing unit 56 connected to the arithmetic control unit 54 via a data bus 55 are built in. The input / output terminal of the input / output processing unit 56 is connected to a lamp driving unit 57, which is a controlled operation unit of the vehicle, and other components not shown in the drawings, and a signal generation unit of the vehicle. For example,
A switch 58 for operating a retractable headlamp, etc., and a sensor 5 for detecting an operating state of an air conditioner, etc.
9, other components not shown are connected.

Further, although not shown, the other nodes 35 are connected to the low-speed communication line 12 via the bidirectional drop-in line 41, as in the front light node 21 or the instrument panel node 23. A multiplex communication unit connected to the multiplex communication unit, an operation control unit connected to the multiplex communication unit via a data bus, and an input / output processing unit connected to the operation control unit via the data bus. The processing unit is connected to an operated control unit or a signal generation unit arranged in each unit of the vehicle.

In the front light node 21, the input / output processing unit 46 and the arithmetic and control unit 44 form low-speed digital control information based on a signal from a switch 49 or the like connected to the input / output processing unit 46. The digital control information formed by the information forming unit including the input / output processing unit 46 and the arithmetic and control unit 44 is transmitted to the low-speed communication line 12 through the bidirectional service line 41 by the multiplex communication unit 42. Sent to Further, even in the instrument panel node 23, the input / output processing unit 56 and the arithmetic control unit 54 provide low-speed digital control information based on signals from the switches 58, sensors 59, and the like connected to the input / output processing unit 56. And an input / output processing unit 56
The digital control information formed by the information forming unit composed of the communication control unit 54 and the low-speed communication line 1
2 is sent.

As described above, a plurality of high-speed communication line nodes including the engine node 15 are connected to the high-speed communication line 11, and a plurality of low-speed communication lines including the front light node 21 are connected to the low-speed communication line 12. In an example of a multiplex transmission apparatus according to the present invention, which is configured by connecting system nodes, a high-speed digital control in which multiplex communication is performed via a high-speed communication line 11 among a plurality of high-speed communication line system nodes. Each of the information and each of the low-speed digital control information that is to be subjected to the multiplex communication between the plurality of low-speed communication line-related nodes via the low-speed communication line 12 is transferred to the high-speed communication line 11 or the low-speed communication line 12. Information format at each high-speed communication line node or low-speed communication line node to send The parts, the data frame is formed as forming, by multiplex communication portion that information forming section are connected with a form of the data frame speed communication line 11 or the low-speed communication line 12
Sent to

A data frame unit formed based on such high-speed or low-speed digital control information is, for example, a group of code data having a predetermined total number of bits, for example, 99 bits as shown in FIG. The contents are an 8-bit frame start marker SOF, 8-bit data PR relating to the priority, and 8-bit data TYP, which represents a data frame unit type, and 8-bit data. , Data ID indicating the type of digital information to be transmitted, and data DT0, DT1, each having an 8-bit structure, indicating digital information to be transmitted.
DT2 and DT3, 8-bit error correction data CRC, 16-bit information reception confirmation data A
NC, 10-bit frame end marker EO
F and idling marker IDL of 1-bit configuration
Are sequentially connected.

In a data frame unit which is a group of code data as shown in FIG.
The data PR relating to the priority of the bit configuration is such that the upper 4 bits are data DT0, DT1, DT2 and DT3.
Of the digital information represented by all or part of the data frame, is information priority data IPR which is a code data representing a priority according to the content thereof, and the lower 4 bits are information forming the data frame unit. The node address data NAD, which is code data indicating the node to which the forming unit belongs and having a priority determined in advance, is used. Therefore, each data frame unit is composed of data DT0, DT1,
The high-speed or low-speed digital control information represented by all or a part of DT2 and DT3 is added with information priority data IPR, node address data NAD, and other code data.

In each of the high-speed communication line nodes and each of the low-speed communication line nodes, information priority data, which is the upper 4 bits of the data PR relating to the priority, which is set when a data frame unit is formed by the information forming unit. The correspondence between IPR data codes and digital information and their priorities are, for example, as shown in Table 1 below. Such information priority data IP
The priority of digital information represented by R is
In general, the higher the importance of the digital information or the shorter the operation response time desired for the digital information, the higher the value.

[0025]

[Table 1]

In each of the high-speed communication line nodes and the low-speed communication line nodes, a node address that is set when the information forming unit forms the data frame unit and that forms the lower 4 bits of the data PR relating to the priority order. The correspondence relationship between the data code of the data NAD and the high-speed communication line system node and the low-speed communication line system node and its priority are as follows: the correspondence relationship between the data code of the node address data NAD and the high-speed communication line system node and its priority are as follows. For example, the correspondence between the data codes of the node address data NAD and the low-speed communication line nodes and their priorities are shown in Table 2 below, for example, as shown in Table 3 below. .

[0027]

[Table 2]

The priority order of the node address data NAD shown in Table 2 is based on each node address data NAD.
Is set in advance in consideration of the contents of the high-speed digital control information transmitted by the high-speed communication line node represented by.

[0029]

[Table 3]

The priority order of the node address data NAD shown in Table 3 is also determined by each node address data NAD.
It is set in advance in consideration of the content of the low-speed digital control information transmitted by the low-speed communication line node represented by AD.

Under such circumstances, in the example of the low-speed communication line system node connected to the low-speed communication line 12 shown in FIG.
Switch 58 connected to the input / output processing unit 56 in 3
Is operated, the instrument panel node 23
Is the transmitting node and the front light node 2
An operation state is set in which low-speed digital control information is transmitted under the condition that 1 is a receiving node. In that case,
In response to the operation of the switch 58, a control signal SS is supplied from the switch 58 to the input / output processing unit 56 in the instrument panel node 23.

At this time, the instrument panel node 2
3, the digital data DS based on the control signal SS is formed in the input / output processing unit 56 to which the control signal SS is supplied, and the formed digital data DS is supplied to the arithmetic and control unit 54 through the data bus 55. You. The arithmetic and control unit 54 forms the low-speed digital control information DIL according to the digital data DS so as to form a data frame unit as shown in FIG. At this time, the arithmetic and control unit 54 represents all or a part of the data DT0 to DT3 in the data frame unit based on the low-speed digital control information DIL as the digital data DS, and outputs the data PR regarding the priority in the data frame unit. In setting, the digital data DS is used as digital information, as shown in Table 1, as information priority data IP
The data code of the information priority data IPR is set based on the correspondence between the data code of R and the high-speed or low-speed digital control information and the priority thereof, and the data P is set.
The upper 4 bits of R, and as shown in Table 3,
The data code "0011" corresponding to the instrument panel node 23 is selected from the correspondence between the data code of the node address data NAD and the low-speed communication line node and the priority order, and the data code of the node address data NAD is thereby selected. Is set as the lower 4 bits of the data PR.

The low-speed digital control information DIL formed by the arithmetic and control unit 54 in this way is supplied to the multiplex communication unit 52 through the data bus 53. In the multiplex communication unit 52, according to the low speed digital control information DIL, the NRZ
A modulated carrier signal SIL is formed, and the formed NRZ modulated carrier signal SIL is transmitted to the low-speed communication line 12 through the bidirectional drop-in line 41.

On the other hand, in the front light node 21, the NRZ modulated carrier signal SIL transmitted from the multiplex communication unit 52 of the instrument panel node 23 to the bidirectional communication line 41 and transmitted through the low-speed communication line 12 is Low-speed communication line 12 to bidirectional service line 4
1 and is taken into the multiplex communication unit 42. Then, in the multiplex communication unit 42 in the front light node 21, the captured NRZ modulated carrier signal SIL is demodulated to reproduce the low-speed digital control information DIL, and the reproduced low-speed digital control information DIL is calculated via the data bus 43. It is supplied to the control unit 44.

The reproduced low-speed digital control information DIL
Is supplied to the arithmetic and control unit 44 which reproduces the digital data DS from all or a part of the data DT0 to DT3 in the data frame unit formed by the low-speed digital control information DIL, and reproduces the digital data DS through the data bus 45. 46.

In the input / output processing unit 46, a control signal SA based on the digital data DS is formed, and the control signal SA is supplied to, for example, an actuator 47 connected to the input / output processing unit 46. And the control signal SA
Supplied to the actuator 47, the control signal SA
A predetermined operation is performed under the operation control by the.

As described above, multiplex communication of high-speed digital control information between a plurality of high-speed communication line nodes via the high-speed communication line 11 and low-speed communication between the plurality of low-speed communication line nodes via the low-speed communication line 12 When multiplex communication of digital control information is performed, the high-speed communication line 11
The high-speed digital control information transmitted to the low-speed communication line and the low-speed digital control information transmitted from each low-speed communication line node to the low-speed communication line 12 form a data frame unit as shown in FIG. At the same time, the data frame unit indicates the node to which the information forming unit forming the data frame unit is formed by the information priority data IPR indicating the priority order of the digital information to be transmitted, forming the upper 4 bits. It is assumed that node address data NAD of which priority is determined in advance includes data PR regarding priority, which forms the lower 4 bits. Thus, for example, a situation in which two or more high-speed communication line nodes simultaneously transmit high-speed digital control information to the high-speed communication line 11 or two or more low-speed communication line systems When low-speed digital control information is transmitted from each of the nodes at the same time, two or more high-speed digital control information or low-speed digital control information to be transmitted at the same time are transmitted to the data frame formed by each of them. According to the priority determined by the data PR relating to the priority in the unit, the status is transmitted in the order, and the transmission collision of two or more high-speed digital control information in the high-speed communication line 11 or the transmission in the low-speed communication line 12 is performed. Transmission collision of two or more low-speed digital control information There is avoided.

Further, in addition to the above, the high-speed communication line 1
The high-speed digital control information fetched at each of the high-speed communication line node that has fetched the high-speed digital control information from the low-speed communication line 12 and the low-speed communication line node that has fetched the low-speed digital control information from the low-speed communication line 12 The high-speed digital control information or the low-speed digital control information taken in based on the node address data NAD constituting the data PR relating to the priority in the data frame unit formed by the information or the low-speed digital control information, Whether or not the communication line node has been transmitted can be easily detected. Moreover, the node address data NAD included in the data frame unit formed by the high-speed digital control information or the low-speed digital control information forms the lower 4 bits of the data PR relating to the priority in the data frame unit. There is no risk that the number of constituent bits in a data frame unit is increased by the data NAD.

[0039]

As is apparent from the above description, in the multiplex transmission apparatus according to the present invention, digital control information is transmitted from each node unit to a communication line, for example, in the form of a data frame unit. In doing so, a data frame unit based on the digital control information is formed by the information forming unit built in each node unit as code data relating to the priority order added to the digital control information, and the code data relating to the priority order is formed. Is composed of the first code data representing the priority of information and the second code data representing the node to which the information forming unit belongs and having a predetermined priority. In the node unit that has fetched the data frame unit transmitted to the Based on the code data about the priorities contained in its whether the data frame that is obtained is sent to the communication line from one node unit,
As necessary, it is not necessary to easily detect a situation where the number of constituent bits per data frame is significantly increased.

[Brief description of the drawings]

FIG. 1 is a partial configuration diagram specifically showing a portion of a multiplex transmission apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram showing an example of a multiplex transmission device according to the present invention in a state applied to a vehicle.

FIG. 3 is a conceptual diagram serving to explain a data frame unit formed by digital control information in an example of the multiplex transmission apparatus according to the present invention.

[Explanation of symbols]

 11 High-speed communication line 12 Low-speed communication line 15 Engine node 16 Main fuse node 17 ABS node 18 4WS node 19 Rear left node 20 Rear right node 21 Front right node 22 Front left node 23 Instrument panel node 24 Cowl left node 25 Center console Node 26 Accessory switch node 27 Front left door node 28 Rear left door node 29 Front right door node 30 Rear right door node 31 Tail node 32 Column node 33 Cowl right node 34 Meter node 42,52 Multiplex communication unit 44,54 Arithmetic control unit 46,56 Input / output processing unit 47 Actuator 48,57 Lamp driving unit 49,58 Switch 59 Sensor

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Kasai 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-5-300570 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) H04Q 9/00-9/16 B60R 16/02

Claims (3)

(57) [Claims] 1. A communication line through which a plurality of types of digital control information are multiplexed and transmitted, an information forming unit connected to the communication line, each forming digital control information, and a digital control information formed by the information forming unit. And a plurality of nodes each having a built-in communication unit for transmitting to the communication line. An information forming unit in each of the plurality of nodes is formed by the information forming unit. The digital control information includes first code data representing the priority of the information, and second code data representing a node to which the information forming unit belongs and having a predetermined priority. A multiplex transmission apparatus characterized in that the multiplex transmission apparatus includes code data associated with the multiplex transmission data. 2. An information forming section in each of a plurality of node sections, wherein the first code data and the second code data are converted into upper bit data and lower bit in the code data relating to the priority formed by a predetermined number of bits. 2. The multiplex transmission device according to claim 1, wherein the multiplex transmission device is obtained as data. 3. An information forming section in each of a plurality of node sections stores the first code data and the second code data in 8 nodes.
3. The multiplex transmission apparatus according to claim 2, wherein upper four bits of data and lower four bits of code data relating to the priority formed by bits are obtained.