JPS5850848A - Information transmission system - Google Patents

Abstract

PURPOSE:To improve the reliability of a system by transmitting terminal reset information from a central controller to a terminal device, and sending out necessary information after a terminal device disabled to perform reception is reset and then preventing a failure in control by the controller. CONSTITUTION:Transmission lines L1 and L2 are connected to a central controller CT, and plural terminal devices TE1-TEN are connected to those transmission lines L1 and L2 in parallel to perform two-way information transmission. From this controller CT, address information and control information are sent to the devices TE1-TE4 by using the transmission lines L1 and L2. According to the presence of the information on the transmission lines L1 and L2, the information is transmitted in four states, i.e. a terminal stand-by state, a terminal reset state, a transmitted-information present state, and a no-information state. Then, terminal reset information is transmitted to reset a reception-disabled terminal on the side of the controller CT, and necessary information is sent out on the resetting. The transmission lines L1 and L2 are switched to return sent- back information from the devices TE1-TEN to the controller CT synchronously with a synchronizing signal transmitted via the other transmission line L1 or L2.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention connects the central control unit and the number of heating caps in parallel via the transmission line 11m. ＃Information transmission in the buying direction between the control device and each terminal device [Relates to transmission method〇Generally, 1 charge central control system, heavy meter reading system, etc. 1
In a system with a large number of control devices installed over a wide area, when transmitting control information from one control device to a terminal, consideration must be given to the information transmission system and system used. - This is defined by the required functions of the control system of the control terminal 1, and is as follows - (1) Since there are many terminals, there is a lot of address information.

(2) Terminal control information is simple ON/OFF information.

(3) Since the control results are confirmed by other methods, it is not necessarily necessary to know the control results of each terminal.

(4) It is necessary to realize the cost commensurate with the economic effect obtained by load control.

A commonly used method to satisfy these conditions is to configure the terminal in a passive manner and to receive commands from a central controller (
1 One example of this is the system shown in the special bulletin No. 18BB-43149. This system uses a multicore cable as a transmission line and a 5III multicore cable. It consists of an address line and a control line, and all fs* and the central control unit are connected in parallel to a multi-core transmission line, and the central control unit connects the terminal to be controlled to the address line of the multi-core transmission line. The device sends an address and control information to the control line, and each terminal checks the information on the address line with its own address, and when they match, performs a predetermined operation based on the information on the control line. 0In such a system, the transmission line is composed of multicore cables, so
It had the disadvantage of high costs for transmission line construction, terminal connection work, etc. - On the other hand, in order to solve this disadvantage,
For example, as shown in Japanese Patent Laid-Open No. 50-116944, transmission lines are separated into two types, one for relay signals and one for information signals, and information signals, that is, address information, and control signals are synchronized with clock signals. According to this method, the transmission path only needs to transmit 21111 signals of the ivy signal and the information signal, so %2 to 4 lines or fIII must be cotransitioned. However, this method has the following drawbacks: 1) The central control system is a system that cannot sense the status of the terminals, so there is only 1 control; If the terminal's digital circuit malfunctions due to noise or the like, information signals from the central control unit cannot be received correctly. In particular, this kind of phenomenon can be fully expected for devices that include counter circuits, shift register circuits, etc. in the terminal.And when this kind of situation occurs, the central control unit will be forced to normalize the terminal. Therefore, the control device becomes completely powerless in regards to such a phenomenon.This invention was made in view of the above, and the central control device is capable of handling terminals that cannot receive data. The purpose of this invention is to eliminate the above-mentioned drawbacks by normalizing the equipment, and to improve the reliability of the information transmission system without increasing the number of transmission lines. According to this invention, the purpose of The four states to be transmitted are assigned as function information: terminal standby, terminal reset, transmission information present, and transmission information absent. After that, the desired information is sent out, and by switching either one of the transmission lines, the return information from the terminal device is synchronized with the synchronization signal sent through the other transmission line and sent back to the control device. 0 is achieved by In Ojlflm, which is a time chart showing
~TIN is the terminal *device s Ll t L- is the transmission line 0 ' The terminal device T111 is the transmission IIL1. The 0 control device CT connected in parallel to L2 by the so-called multi-drip connection method has two transmission lines L1.
One address information and control information is sent to a plurality of terminal devices TEI to TIN using sL2. Each terminal device T
El-TgN transmits information from the central controller CT to the transmission line L.
1 t A terminal tree device τB that performs a predetermined operation based on the control information only when the address information is received via the I4 and matches its own predetermined address.
1-Return information from TBN is transmitted through two transmission lines L1 f 7
-42 is switched and the signal is sent back to the control device CT via the transmission path, but at this time the control device CT sends out a synchronization signal via the other transmission path.
The return information will be sent out in synchronization with this synchronization signal.

The present invention provides such a system with a unique meaning or function depending on the presence or absence of information transmitted via the transmission path. That is, the transmission path Ll e L!
Since the presence or absence of information corresponds to each of the above, there are four possible cases as shown in the table below.

Corresponding to the four cases (1) to (d) of the reward, each has a unique meaning t〆 has a function. h”, (c)
Case (d) is assigned as ``no information to be transmitted'', and case (d) is assigned as ``information to be transmitted''. The correspondence between the functions of the 14 types and the four cases can be determined as appropriate. 1 Conventionally, the desired information can be transmitted by transmitting information as shown in Table (b) above and resetting a terminal device that is unable to receive data due to malfunction etc. It has a function to deal with malfunctions of the terminal equipment, which was not possible with the transmission method. This refers to an operation that returns a device (terminal device) to its initial state, such as, when the terminal device receives this signal, it returns to its initial state regardless of its state. A time chart showing transmission operation.
For example, (b) is the transmission information sent to transmission @Ll, and (4) is the information sent to the transmission line L2, saving (c)
is address information given to the terminal device, and (d) indicates information returned from the terminal device.

In other words, in order to make a terminal tree device, it is necessary to use (1) in the above table.
According to the promise in 1), the transmission line IJI e l! Neither of them transmits information, and when the terminal device should be reset F, the information is sent only to the transmission path Ll according to the promise in Table 1 (b). Address information as shown in Il (c) (10 if the presence or absence of a pulse is each 1.0)
011101'' information), in the table (
It is only necessary to send information such as 2nd WJ (a) and (b) according to the promises in e) and (d).O The terminal device selected by this address information is the 1st WJ (a) and (0). By combining the information, information like (c) (if the presence or absence of a pulse corresponds to f 1.0, @10
This return information is sent back via the transmission line L1 in synchronization with the synchronization signal from the central control unit sent on the transmission line Lz in the case of SN.

As described above, according to this invention, by sending terminal reset information from the central control unit before sending desired information, it is possible to normalize a terminal device that has malfunctioned due to ivy noise, etc. This method makes it possible to reliably determine the reception of address information sent from the control device, and also allows one of the two transmission lines to be switched and used as the transmission line from the terminal device to the control device after sending out the address information. Even in the case of the invention, the advantage is that it is possible to avoid as much as possible obstacles such as two or more terminal devices sending out signals at the same time or no terminal device being selected.

[Brief explanation of drawings]

No. 111 is a block configuration diagram showing an outline of an information transmission system to which the present invention is applied, and No. 2 WJ is a time chart showing transmission information. Code explanation CT...Central control unit・Tll~T g N-
°°″°°Terminal device, Llm L@/Song/Transmission path agent Patent attorney Akio Namiki Agent Patent attorney Kiyoshi Matsuzaki

Claims (1)

[Claims] A plurality of terminal devices are each connected in parallel to a central control device via two transmission lines, and one of the four states represented by the presence/absence of information sent from the control device onto each transmission line is detected. An information transmission method in which information is transmitted by assigning it as function information of terminal standby/terminal reset, transmission information present, and transmission information not present, in which the control device transmits terminal reset information to prevent reception. After resetting the terminal device in Hoto, the desired information is sent out. 1. By switching either one of the transmission lines, the return information from the terminal device is converted into a synchronization signal sent through the other transmission line. A method of transmitting information that is synchronized and sent back to the control device.