JPS5992653A - Data transmitter - Google Patents

Abstract

PURPOSE:To perform cooperative decentralized control by storing the operation state of each station even at each remote station in a bus transmission system wherein a master station designates remote stations to transmitting and a receiving stations and allows data transfer between the specified transmitting and receiving stations. CONSTITUTION:When the master station 5 designates a remote station 6 to a transmitting station, reading from and writing to the master station are performed from a system bus 10 through an interface 11 similarly to the case of designation of receiving station. Then, a transmitting address register 13 decides on the specified remote station as the transmitting station and stores data on it in a memory 12. The address of this remote station is transmitted to the bus through a checking circuit 15 and a transmitting and receiving circuit 16. The remote station 6 detects address coincidence and stores a selecting circuit 23 with information showing that the remote station is the transmitting station. Another station stores a memory 23 with information showing that the remote station 6 is the transmitting station.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a data transmission device, and when a plurality of controllers share functions and constitute one control system as a whole, data transmission between the individual controllers is performed. The present invention relates to a data transmission device that transmits and receives data.

[Technical background of the invention and its problems]

It is not uncommon for modern large-scale control systems to consist of several distributed controllers. In order to execute the entire control system using a plurality of controllers, each controller must receive the control states of other controllers as data and perform data source processing.

The data transmission devices are 3a, 3b,...3C in Figure 1.
As shown in the figure, multiple controllers la, lb,...
A party line system is often used in which ICs are connected one after another by a pair of transmission cables 4 to perform bidirectional data transmission.

This party line control system usually consists of one master station and multiple IJ mote stations, and the master station connects a remote station designated as a transmitting station and a remote station designated as a receiving station. Data is sent and received at

However, in conventional data transmission devices connected in a party line manner, the remote station does not have a memory for storing transmission data from all other stations, making it difficult to configure a distributed control system.

[Purpose of the invention]

An object of the present invention is to provide a memory for sharing the same data in all stations connected to a controller in a party line type data transmission device, and to transmit a transmission address assigned by a master station to each transmission data. One remote station that identified the transmission address as its own transmission address read the data from its memory and used it as transmission data, and all other stations received the data and stored it in their memory, enabling distributed control. The purpose is to obtain a data transmission device.

[Summary of the invention]

The present invention is a data transmission device using a party line method in which a master station and a plurality of remote stations are connected to the same transmission line and data is exchanged between the stations, in which a transmission address transmitted from the master station is stored. A transmission at 1nos register,
a memory that stores received data in correspondence with the transmission address; a transmission/reception designation switch that designates a predetermined transmission address; and a transmission/reception designation switch that switches to a transmission mode when the predetermined transmission address is received to correspond to the predetermined transmission address. This is a data transmission device that is equipped with a switching circuit that transmits the data stored in the @6 memory and that enables the configuration of a large-scale control system to be OT-enabled.

[Embodiments of the invention]

FIG. 2 is a block diagram of the data transmission device of the present invention.

The data transmission apparatus of the present invention is used in a party line type control system comprising several remote stations 6 and one master station 5 for controlling them.

The master station 5 includes a system path 10 of the controller, an interface 11 for receiving and receiving data signals and control signals, a memory 12 for storing data of the controller and remote stations, an address register 13 for holding transmission addresses, and a master station control system. a control circuit 14 for converting the transmitted and received data from parallel to serial, and a conversion check circuit 15 that simultaneously generates or checks a check code for the transmitted and received data, a driver for data transmission, and a driver for data reception. It is composed of a transmitting/receiving circuit 16.

On the other hand, remote station 6 is master station 5
The configuration is almost the same as that of the master station, but the difference is that each station has a selection circuit that determines whether it is a transmitting station or a receiving station based on the transmission address data sent by the master station. an interface 21 for connecting with the system path of another controller;
Memory anxiety, +ttlJ control circuit prisoner, circuit check circuit 5,
The transmitter/receiver circuit is constructed later.

tr at remote station 7, which consists only of input and output devices.
i As shown in FIG. 4, no memory is required, and the system path 40 of the input/output device is directly connected to the interface 41 of the data transmission device.

The memory 12 of the master station is read from or written to via the ink face 11 from the system path 10 of the controller. Further, the transmission address register 13 determines a remote station designated as a transmitting station, and the received data is stored in the memory 12. If the above two operations overlap, the control circuit 14 performs processing such as giving priority to preemption. Since the memory 12 is directly interfaced with the controller, it is composed of multiple bits for one address, but since the transmission data is serial transmission that transmits one bit at a time, a conversion check is performed between the memory 12 and the transmitting/receiving circuit 16. A circuit 15 performs serial-parallel data conversion. In addition, the conversion check circuit 15 generates a check code such as a parity bit on the transmitting side and adds it to the data in order to check the operation of the data conversion and transmission circuit, and checks the validity of the data including the parity bit on the receiving side. Perform actions such as flipping.

FIG. 3 is a detailed circuit diagram of the selection circuit B of the remote station 6. The remote station 6 uses the transmission/reception designation switch 31 of the selection circuit to turn off the switch for the transmission address that it transmits, and sets the input port sick level of the transmission address to "1" using the pull-up resistor 32. When the transmission address bit of the transmission address register 33 received from the master station 5 matches the transmission address of the transmission/reception designation switch 31, the selection circuit decreases.
A transmit mode signal is generated. Memory n for each control circuit
The data specified as the transmission address is read out from the address, and the data is transmitted to the transmission cable by the conversion check circuit 5 and the transmission/reception circuit A.

On the other hand, all other remote stations 6 that are not designated as transmitting stations receive the data transmitted by the transmitting station at their transmitting/receiving circuits A, and after data conversion, store them in the memory B at the transmission address designated by the register 33.

Remote station 7 consisting only of input/output devices
Unlike other stations, it does not need to use memory. Instead, the system bus 40 of the input/output device is connected to the interface 41 of the data transmission device. Selection circuit 4
3 specifies the operation of receiving data transmitted from another station, the data converted by the transmitting/receiving circuit 46 and the conversion check circuit 45 is sent to the digital output device via the system bus 40 of the input/output device.
Or output to an analog output device. Furthermore, if the selection circuit 43 is set to transmit operation for the transmission address from the master station, data is input from the digital input device or analog input device via the system bus 40, and the data is input to the conversion check circuit 45 and the transmission/reception circuit. 46 to transmit data.

Data transmission devices connected to other controllers receive this data and then store it in memory, so all stations can share the same data.

Note that the master station described above only transmits the transmission address register to simplify the explanation, but the master station is also equipped with a selection circuit for transmission and reception addresses, and can transmit its own data in the same way as remote stations. It is self-evident that it can be transmitted to all remote stations.

Further, although the transmission/reception designation switch for comparison with the transmission address has been explained using a switch for simplicity, it can be similarly realized using a non-destructive continuous read only memory (P LOOM ).

〔Effect of the invention〕

According to the data transmission device of the present invention, it is possible to obtain a data transmission device that can be configured as a party system.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a control system connected by a party line, FIG. 2 is a block diagram of a data transmission device of the present invention between a master station and a remote station, and FIG. 3 is a P#1 circuit diagram of each selection circuit. Figure A4 is a block diagram of the data transmission device of the present invention for input/output equipment. la, lb, IC controller 2a, 2b, 2C...system bus 3a, 3b, 3c...data transmission device 4...transmission cable 5...master station 6.7...remote station 10 , Addition... System bus 11.21... Interface 12.22... Memory 1; 3... Transmission address register 14, 24... Control 141 circuit 15, '5... Conversion check circuit 16, z6...Transmission/reception circuit...Selection circuit; 31...Transmission/reception designation switch 32...Pull-up resistor: 33...Transmission address register...Selection circuit...Transmission mode signal (7317) Representative Patent Attorney Kensuke Norichika (and 1 other person) 11
1) Figure 1 Figure 2

Claims (1)

[Claims] In a party line data transmission device in which a master station and multiple remote stations are connected to the same transmission line and data is exchanged between the stations, a transmission address register stores the transmission address transmitted from the master station. and a memory for storing received data in correspondence with the transmission address;
a transmission/reception designation switch for specifying a predetermined transmission address;
A data transmission device comprising a switching circuit that switches to a transmission mode when the predetermined transmission address is received and transmits data in the memory corresponding to the predetermined transmission address.