JPS59154839A - Transmission control system - Google Patents

Abstract

PURPOSE:To improve the reliability by using a new transmission format in a system where a common transmission line such as loop is used, information such as sensor is transmitted to a slave terminal to a central device and control information is transmitted cyclicly from the central device to the slave terminal. CONSTITUTION:A transmission frame is repeated cyclicly at each T1. Frames #0, 1 are used for trasmitting a signal from the central device to the slave terminal, and frames #2-8 are used for transmitting the inforation such as sensor by the slave terminals 2-8. Further, a DS is space. The frames #2-#8 consist of a start section STB and a data section DB, a slave station and a data are designated by the start section TB, and the signal is transmitted by the data section DB of the designated station. The frames #0, 1 designate similarly the start section STB and transmits the data section DB succeeding to it to the designated station.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is one form of a multiplex transmission system in a transmission control system for transmitting command information from a driving control device in a vehicle or the like or for transmitting input information from various sensors to an information processing device. As a result, a multiplex transmission harness system was developed that consists of a loop-shaped multiplex transmission line and several communication control devices, or terminals, mounted on the loop-shaped multiplex transmission line. Each terminal of this multiplex transmission harness system is associated with load equipment such as nearby operating equipment and various warning indicator lamps, depending on its location, and information for operating these load equipment is transmitted multiplexed. Receive via . In addition, depending on the location of each terminal, there are sensors that monitor the status of various devices, operation control devices, and switches that command and operate various warning and indicator lamps that are located nearby9. Information from sensors and switches is transmitted to display devices, operating devices, or terminals associated with various lamps via multiple transmission lines.

In the multiplex transmission system as described above, a centralized control method and a distributed control method are known as load control methods. The centralized control method centralizes the collection, arithmetic processing, and editing of information for the entire control system, and as many electrical components are used to control vehicle operation in recent years, the central terminal becomes somewhat complex. ,
The processing functions of terminals other than the central one are simplified, and the overall configuration is simpler than that of a distributed control system.

An object of the present invention is to provide a low-cost, highly reliable transmission control system that is widely applicable to multiplex transmission systems using loop-type multiplex transmission lines as described above.

The transmission control system according to the present invention achieves the above object, in a multiplex transmission system consisting of a common multiplex transmission line and central terminals and local terminals arranged along this line, the central terminal sequentially controls the local terminals. In response to the call, each terminal sends information on switches and sensors related to that terminal to the multiplex transmission line, and the central terminal receives and processes the sent information. Edit it to create a control signal to all load devices related to the valley local terminal, and after each round of the above call has elapsed a data sending blank time m that follows this round, send the above control signal to all the local terminals. Each local terminal receives the control signal and selects the control signal related to the load equipment to which it belongs.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a block diagram of a multiplex transmission harness system according to an embodiment of the present invention.
#8 is a terminal, among which #1 is a central terminal (abbreviated as CPT), and the remaining #-2 to #8 are local terminals (LP
(abbreviated as T). 9 is a bidirectional loop-shaped multiplex transmission line, and 10 is a meter panel. Each terminal #1 to #4 #8
As illustrated in LPT #2, a load device 11 and switches and sensors 12 are involved.

CPT$1 transmits a load control signal for controlling the load devices 11 associated with each terminal #1 to #8. This load control signal is called CPT information.

Local terminals +2 to #8 transmit information about the switches and sensors 12 associated with themselves in response to the transmission request signal that CPT #+1 sequentially requests each terminal to transmit. This information is called LPT information. In this embodiment, the meter panel 10
is the local terminal to which it belongs (as it is a meter panel terminal, M
Since CPT #4 receives information from other terminals, including CPT #1, and collects, processes, and edits the data necessary for meter panel display, CPT #+1 receives not only CPT information. As a type of local terminal, it makes its own calls and sends LPT information.

According to the transmission control system of the present invention, L from each terminal to the central terminal in a multiplex transmission control system as shown in FIG.
The transmission of PT information and the transmission of CPT information to the load control equipment of each terminal according to the processed information can be implemented in one example of a transmission format as shown in FIG.

What is shown in Fig. 2 shows transmission 7 times If by the cyclic transmission method with an okiya period T, and a calling time interval T2.
-i (i=0, 1, 2-8) is composed of nine 7 frames #O to #8 and the remaining blank time DS. CPT information from CPT$1 is Oth frame #0
It is located in The central terminal CPT#1 has a ringing time MTt-i including from cp'r+1 to LPT$8
The terminals are called one after another by sending transmission request signals in a predetermined order. In response, each terminal transmits LPT information within the called frame.

Note that the paging time intervals T and -i of the transmission format do not necessarily have to be constant periods, and can be determined to be an appropriate length depending on the terminal.

FIG. 3 shows the frame structure, and FIG. 4 shows the structure of the STB (start-by for transmission requests). FIG. 5 shows the structure of the data byte (DB) transmitted in response to the start byte. Start byte S from CPT#1 at the beginning of each frame
TB is transmitted, bits b0 to b, and 04 of this indicate the terminal number, and the terminal with this number is the destination of the transmission request. b.

The three bits ~b and 0 specify the number of data bytes of LPT information to be transmitted. When the highest digit is b = 1, it indicates the start byte STB. Data byte DB is identified by the most significant digit, b0~b,0
LPT information such as switch information and sensor information is written in 7 bits. The 4 bits bo to b of the start byte STB can cover local terminals from 0 to 15, which is a sufficient number for automobiles and the like.

In addition, the transmission request byte number b4 to b603 bits can specify bytes from 0 to 7 bytes, and if the amount of data is about the same as a car, the maximum is 7 bytes.
-49, it is sufficient to allocate 97 bytes per 7-bit data byte DB'il terminal. Also, CPT information is 7
It is also possible to send data larger than bytes. The terminal specified by the start byte STB from the CPT 41 sends out the LPT information of the terminal in the frame to the CPT 1 via the multiplex transmission path 9 to the DB. The DB of each terminal is not constant and may vary due to differences in the type and number of sensors, number of switches, etc.

However, the number of data bytes in each LPT is memorized by CPT+1, and the number of data bytes in STB is specified.

When the local terminal sends a data byte in response to the start byte sent by CPT$1, each terminal sends the number of data bytes specified by STB and the data to be sent in response to this start byte. Compare the number of bytes and use it to check whether the data bytes to be sent are correct or incorrect.

CPT$1 receives the data (by) DB sent from each local terminal, processes and edits it, and compiles it into a control signal that controls the load equipment associated with each local terminal and sends it to the CP.
CPT information is generated, and after each terminal has made a round of calls and the data transmission blank time DS has elapsed, the CPT information is transmitted to all terminals in frame #0, that is, at every transmission cycle T1. Each terminal is a CP
It receives the T information and selects the load control signal associated with each terminal to control the load equipment.

It should be noted that the calling time interval of the start byte is constant T,
Number of local terminals 'ltn % data transmission blank time D
S, the above transmitting station m=z T+ and the ringing time interval T
2, T+ = (n + 1) Tl + D
It becomes B.

In the transmission format shown in FIG. 2, one local terminal number i=1 is given to the central terminal CPT as described above,
CPT+1 is calling itself like a local terminal. This allows the CP to be applied to a specific terminal other than the CPT, for example, MPT+4 to which the meter panel shown in FIG.
It is possible to receive information from local terminals including T, collect data necessary for displaying the meter panel, process it, edit it, and display it. That is, by transferring part of the functions of the central terminal in the centralized transmission control system to other terminals, the concentration of load on the central terminal can be dispersed, the burden can be reduced, and the efficiency of the entire system can be increased. Of course, if the other terminal does not need the LPT information of CPT#1,
There is no need to make a PT$1 call.

Next, an example of the configuration of each terminal will be explained.

The example shown in FIG. 6 is an example in which an optical fiber is used as the multiplex transmission line 9, and 13 is an electric/
14 is an optical converter consisting of a phototransistor and its receiver, 15 is a connection switch, 16 is a serial/parallel signal format converter, 17 is a microcomputer, and 18 is a microcomputer 17 board. A watchdog timer commands the start, 19 is a control output to the load equipment, and 20 is an input from switches and sensors.

Assuming that the terminal shown in Figure 6 is a local terminal, the load devices may include lamps such as horns, headlamps, turn lamps, motors for remote control mirrors, or solenoids of drive devices. is driven by a solid-state semiconductor relay or the like. Various types of sensors can be considered as sensors, such as those for detecting disconnection of each of the lamps, blowing of fuses, oil pressure, and lining, and information on the switches as well as these sensors is input to the microcomputer 17 via the interface circuit. At the terminal, a serial bit optical pulse signal is input to the optical/electrical converter 14 via the optical multiplex transmission line 9, and this is converted to parallel bits and input to the microcomputer 17. If it is CPT information, this terminal The control information of the operation command for the load device is selected and the load device is driven. On the other hand, in the case of a transmission request, the LPT information of switches and sensors input to the microcomputer 17 is converted into serial bits, and then converted into an optical pulse signal by the electric/optical converter 13 and sent to the optical transmission line 9.

Next, if the terminal in FIG. 6 has a CPT of $1, all LPT information from each terminal is collected in the microcomputer 17, and various control signals for the operation of each load device of each terminal are edited from this LPT information. , is sent as CPT information. In addition, since CPT$1 monitors each terminal by a program as in the normal centralized control system, its microcomputer 17 has data transmission routine, data reception routine, monitoring routine, load equipment of each terminal, switch and sensor. control routines and fault mode control routines.

In the transmission control method according to the present invention, a control byte called the start byte performs important timing control, so there is no need for a timer in the local terminal, which simplifies the structure of the local terminal and reduces the price. Become. Further, in the present invention, the number of bytes requested to be transmitted in the start byte can be made variable once every few times, for example, 2 bytes at all times and 5 bytes once every 10 times. This eliminates the waste of processing information that does not change much each time, such as sensor information. In the transmission format of the transmission control system according to the present invention, as shown in FIG. 2, after CPT#-1 calls each terminal once, a data transmission blank time called DS is provided. During this data transmission blank time, the microcomputer 17 of each terminal processes data to prepare data for transmission, and performs tttlJ control of the load equipment based on the received CPT information. Although data transmission is slightly delayed due to this data transmission blank time, high-speed processing of the entire system is realized.

According to the transmission control method of the present invention, it is widely applicable to multiplex transmission systems using loop-type multiplex transmission lines, and it is possible to realize a low-cost and highly reliable multiplex transmission system.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a multiplex transmission harness system as an example of a target for implementing the present invention, FIG. 2 is a diagram showing an example of a transmission format used in the present invention, FIG. 3 is a frame configuration diagram, and FIG. The figure is a configuration diagram of the start bite, 5th
The figure is a configuration diagram of a data byte, and FIG. 6 is a configuration diagram showing an example of a terminal. In the drawing, 4#1 is the central terminal, #2 to #+8 are the local terminals, 9 is the multiplex transmission line, 10 is the meter panel, 11 is the load equipment, 12 is the switch and sensors, 13tlj, [air/optical conversion 14 is an optical/electrical converter, 15 is a connection switch, 16 is a serial/parallel converter, 17 is a microcomputer, 19 is a control output to load equipment, and 20 is an input for switches and sensors. Patent Applicant Sumitomo Electric Industries Co., Ltd. Agent Patent Attorney Shibu Mitsuishi (1 other person)

Claims (1)

[Claims] (1) In a multiplex transmission system consisting of a common multiplex transmission line and a central terminal and local terminals arranged along this line, the central terminal cyclically calls each local terminal in a prescribed order, and each In response to a call, a terminal sends information on switches and sensors related to that terminal to the multiplex transmission line, and the central terminal receives, processes, and edits the sent information and sends it to each local terminal. A control signal is created for all the load devices, and after each round of the above call, the data transmission blank period following this round has elapsed, the above control signal is sent to all local terminals, and each local terminal receives the above control signal. A transmission control method characterized by receiving and selecting a control signal for a load device that is associated with itself. (匈) The above call is made by sending a start byte containing a transmission request terminal number that designates the transmission request terminal and a designation of the number of data bytes that the designated terminal should send. A terminal that is requested to send information transmits information on switches and sensors associated with that terminal using the specified number of data bytes until the next start byte for other terminals is sent from the central terminal. A transmission control method according to claim 1, characterized in that: