JPH01204532A - Terminal control system - Google Patents

Abstract

PURPOSE:To allow the system to cope flexibly with the revision in system constitution by providing a device converting a 4-wire line into a 2-wire line. CONSTITUTION:When an outgoing communication control means 131 of a line converter 103 detects outgoing information, an outgoing line transmission means 132 is driven to send the outgoing information to a terminal equipment 104, and on the other hand, when an incoming communication control means 133 detects incoming information, an outgoing line transmission means 134 is driven to send the outgoing information to a controller 101 and a standby controller 102, then a 4-wire line is converted into a 2-wire line. A 1st controller 101 and a 2nd controller 102 store a data included in the incoming information into information storage means 111, 121 simultaneously to share the data in common. Thus, plural controllers are connected in parallel with the line and it is possible to allow the system to cope flexible with the revision of the system constitution such as addition of the controller.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems Action Examples ■, Correspondence between the Examples and FIG. 1 ■ , Configuration of the embodiment (i) Configuration of the entire system (ii) Configuration of the line converter (iii) Configuration of the high impedance detection circuit (iv)
Configuration of the transmitting circuit■, Operation of the embodiment (i) Operation of the line converter (ii) Operation of the entire system■, Summary of the embodiment■0 Variations of the invention Effects of the invention [Summary] Having multiple control devices With regard to terminal control systems, the purpose is to flexibly respond to system configuration changes such as the addition of control devices, and at least one terminal device that communicates data via a 4-wire line and that stores data from the terminal device. A plurality of control devices each having an information storage means and communicating with or intercepting the terminal device through a two-wire line and accumulating data from the terminal device, and a four-wire line transmitting downlink information to the terminal device. downlink transmission means for transmitting to the downlink of the terminal device, downlink communication control means for detecting downlink information and controlling the downlink transmission means, uplink transmission means for transmitting uplink information from the terminal device to the two-wire line; one control device in communication with a terminal device, comprising an uplink communication control means for detecting information and controlling an uplink transmission means and converting a four-wire line into a two-wire line; When an abnormality occurs in the controller, other control devices are configured to perform back-amplification.

[Industrial application field]

The present invention relates to a terminal control system, and particularly to a terminal control system in which a 4-wire communication line is converted to a 2-wire communication line so that a backup control device intercepts communication between a control device and a terminal device. It is.

[Conventional technology]

In order to manage sales, an increasing number of retail stores have introduced POS systems consisting of several PO3 terminals and a controller that manages them.

In such a POS system, in case a failure occurs in the master controller, a backup controller is provided to manage the PO3 terminals in place of the master controller. We are trying to improve reliability.

By the way, in order to perform backup operations of the controller smoothly, information is shared so that the backup controller can use all the information necessary to manage the PO5 terminals, such as sales information accumulated under the control of the master controller. There is a need. Two types of methods have been proposed for this purpose, depending on whether the communication line between the PO8 terminal and the controller is a two-wire type or a four-wire type.

Figure 4 shows the listening method. This method is mainly used when the communication line is a two-wire type.

The master controller 401 and the backup controller 402 each have disk devices 411 and 421 as information storage means. In this method, the master controller 401 and the POS terminals 403 and 404 normally communicate data using a half-duplex method, and data is sequentially stored in the disk device 411. On the other hand, the backup controller 402 is the master controller 401
and listen to the communication between the PO3 terminal 403 and 404,
The obtained data is sequentially stored in the disk device 421.

In this way, since the backup controller 402 has the disk device 421 having the same contents as the disk device 411 of the master controller 401, P
Inherit all the information necessary to manage the O3 terminal and use the PO
It becomes possible to continue managing three terminals.

Next, a method of sharing information when the communication line is a four-wire type will be explained. FIG. 5 is an explanatory diagram of the sharing method.

The master controller 501 and the backup controller 502 share a disk device 503 as an information storage means via a disk switching device 504. In this method, normally the master controller 501 and PO3
The terminals 506 and 507 are connected by a line switching circuit 505 and data communication is performed through a 4-wire line.
The master controller 501 sequentially stores the obtained data in the disk device 503. Since the backup controller 502 shares the disk device 503 itself, it is possible to take over all the information necessary for managing the PoS terminals and continue managing the PO3 terminals.

Although two-wire lines are also used for communication between PO3 terminals and controllers, four-wire lines are often used, and in this case information is shared between the master controller and backup controller. As a way to do this,
The above-mentioned sharing method is adopted.

Here, the backup operation in the shared method will be explained.

When the POS system is operating normally, the receiver 511 of the master controller 501 is connected to receive uplink communication from the PO3 terminal to the controller by the line switching circuit 505.
Data is being received from the device. On the other hand, the receiver 521 of the backup controller 502 is connected to the line switching circuit 5.
05, it is connected to the downlink from the controller to the PO3 terminals, and monitors whether the master controller 501 periodically makes data inquiries to the PO3 terminals 504 and 505.

If an abnormality occurs in the operation of the master controller 501, the backup controller 502 connects the receiver 521 to the uplink via the line switching circuit 505, and exchanges data with the PO3 terminal in place of the master controller 501.

[Problem to be solved by the invention]

By the way, in the conventional method described above, the terminal control system that controls the 4-wire terminal device requires a line switching circuit, a disk switching circuit, etc., so the system configuration is complicated, and the addition of a backup controller is required. It is not possible to respond flexibly to changes in system configuration such as Furthermore, since the disk devices are shared, there is a problem in that if a failure occurs in the disk device itself, the entire system will go down.

The present invention was created in view of these points, and provides a terminal that is equipped with a device that converts a 4-wire line into a 2-wire line, and is able to flexibly respond to changes in system configuration. The purpose is to provide a control system.

[Means for Solving the Problems] FIG. 1 is a block diagram of the principle of the terminal control system of the present invention.

In the figure, a terminal device W104 communicates data through a four-wire line.

The first control device 101 has an information storage means 111 that stores data from the terminal device 104, and stores data from the terminal device 104 by communicating with the terminal device 104 via a two-wire line or by intercepting the data. Do this.

The second control device 102 has an information storage means 121 that stores data from the terminal device 104, and stores data from the terminal device 104 by communicating with the terminal device 104 via a two-wire line or by intercepting the data. Do this.

The line conversion device 103 includes a downlink transmitting unit 132. Downlink communication control means 131 detects downlink information and controls downlink transmission means 132; uplink transmission means 1 transmits uplink information from terminal device 104 to a two-wire line;
34. It has uplink communication control means 133 that detects uplink information and controls uplink transmission means 134, and connects two four-wire lines.
Convert to wire line.

Therefore, overall, the data from the terminal device is shared among multiple control devices using the listening method, and when an abnormality occurs in one control device communicating with the terminal device, other control devices can back up the data. Configure it as follows.

[Function] When the downlink communication control means 131 of the line conversion device 103 detects downlink information, it drives the downlink transmission means 132 to transmit the downlink information to the terminal device 104, while the uplink communication control means 133 , upon detecting uplink information from the terminal device 104, drives the uplink transmission means 134 and transmits the uplink information to the control device 101 and the preliminary control device 102, thereby converting the four-wire line into a two-wire line. . The first control device 101 and the second control device 102 simultaneously accumulate data included in uplink information in the information storage means 111 and 121 and share the data.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows the configuration of a terminal control system in one embodiment of the present invention.

(2) Correspondence between the embodiment and FIG. 1 Here, the correspondence between the embodiment of the present invention and FIG. 1 will be shown.

The first control device 101 corresponds to the controller 201.

The second control device 102 corresponds to the controller 202°.

Line conversion device 103 corresponds to line conversion device 203.

The terminal device 104 corresponds to the PO3 terminal 204.

The information storage means 111 of the first control device 101 corresponds to the disk device 211.

The information storage means 121 of the second control device 102 corresponds to the disk device 221.

The downlink communication control means 131 of the line conversion device 103 includes the downlink high impedance detection circuit 231 of the line conversion device 203.
corresponds to

Downlink transmission means 132 corresponds to downlink transmission circuit 232.

The uplink communication control means 133 corresponds to the uplink high impedance detection circuit 233 of the line conversion device 203.

The uplink transmission means 134 corresponds to the uplink transmission circuit 234.

Examples of the present invention will be described below assuming that the correspondence relationship as described above exists.

In FIG. 2, the PO3 terminal control system includes a PO3 terminal 204 that inputs and outputs sales information, etc., a line converter 203 that converts a 4-wire line to a 2-wire line, and a PO3 terminal 204 that inputs and outputs sales information etc.
Two controllers 201 and 20 that control the terminal 204
2, and disk devices 211 and 221 that are attached to each of the controllers 201 and 202 and store sales information, etc.
It is formed by.

One of the two controllers 201 and 202 always serves as the master controller and controls the line conversion device 20.
3, and the others intercept communication between the master controller and the PO3 terminal 204 and connect the disk devices 211 and 2 attached to each.
The system is configured to share sales information through a listening method that is stored in 21. For example, if the master controller is the controller 201, the controller 201 exchanges data with the PO3 terminal 204, and the controller 202 becomes a back amplifier controller and intercepts communication between the controller 201 and the POS terminal 204.

Since the controllers 201 and 202 are connected in parallel to the two-wire line, it is possible to configure any number of sets of controllers and disk devices connected as a backup controller.

(ii) Configuration of line/switching device The line converting device 203 uses a downlink high impedance detection circuit 231 that monitors the impedance of the two-wire line between the controllers 201 and 202, and an output of the downlink high impedance detection circuit 231. An uplink high impedance detection circuit 233 that monitors the uplink impedance of the four-wire line between the driven downlink transmission circuit 232 and the PO3 terminal 204;
The uplink transmitting circuit 234 is driven by the output of No. 3.

(iii) Configuration of high impedance detection circuit The downstream high impedance detection circuit 231 includes two comparators 241,
242, an exclusive OR gate 243 for calculating the exclusive OR of the outputs of the comparators 241 and 242, and an inverter 244.

The lines are connected to the comparators 241 and 242 so that the positive and negative sides are reversed, and the output of the inverter 244 becomes ``1'' when the line has high impedance (described later). ).

Similarly, the upstream high impedance detection circuit 233 is connected to the comparator 2.
51 and 252, an exclusive OR gate 253, and an inverter 254.

(iv) Prompt downlink transmission circuit 232 of the transmission circuit is formed from two delay lines 245, 246, an AND gate 247, and a driver 248, and the line is kept low for an appropriate amount of time before and after the downlink information signal. It is configured to have an impedance (described later).

Similarly, the uplink transmission circuit 234 has delay lines 255 and 256,
It is formed from an AND gate 257 and a driver 258.

The operation of the line conversion device 203 will be explained with respect to the upstream high impedance detection circuit 233 and the upstream transmission circuit 234. .

FIG. 3 is a time chart illustrating the operation of uplink control in the embodiment.

Reference will now be made to FIGS. 2 and 3.

First, the operation of the high impedance detection circuit will be explained.

When the uplink of the 4-wire line from the PO3 terminal is high impedance, that is, when there is no upstream information (data from the POS terminal 204), the inputs to the comparators 251 and 252 are the same, so both are "1". On the other hand, when the uplink becomes low impedance and uplink information is sent, the inputs to the comparators 251 and 252 are reversed in polarity, so the comparators 251 and 252
Output so that O°゛ and “1” are reversed.

Since the exclusive OR gate 253 takes the exclusive OR of the outputs of the comparators 251 and 252, its output becomes "0" when the uplink has high impedance, and becomes "BI" when the uplink has low impedance.

Since the inverter 254 inverts the output of the exclusive OR gate 253, its output becomes "1'" when the uplink has high impedance, and "1'" when the uplink has low impedance.
It becomes 0pa.

In this way, high impedance is detected on the uplink.

Next, the transmitting circuit will be explained.

A delay line 255 connects the output signal of the comparator 251 to T.

only to be delayed.

Delay line 256 delays the output signal of comparator 252 by T2.

The AND gate 257 takes the AND of the output signal of the comparator 252 and the output signal of the delay line 256, so its output becomes "0''' when the uplink becomes a low impedance, and the output becomes "0"' when the uplink becomes a high impedance. T2 from when it becomes
becomes "1" with a delay of

The driver 258 is configured so that the output of the AND gate 257 is "o
”, it is driven and becomes ready for transmission (enabled),
The output side is connected to a two-wire line and the output of the delay line 255 is transmitted to the controllers 201 and 202. On the other hand, when the output of the AND gate 257 is 1°, transmission is disabled, and the output side is cut off to make the two-wire line high impedance.

In this way, T before and after the uplink information signal, respectively.
, T, to ensure that the signal is transmitted accurately by setting the period during which the driver is enabled.

As described above, the upstream communication on the 4-wire line from the PO3 terminal 204 is passed through the 2-wire line to the controller 201.
, 202.

In addition, downlink information (P
Similarly, requests for data to the O5 terminal 204, etc.
It can be transmitted as downlink information on a 4-wire line.

In this way, the controllers 201 and 202 and the PO3 terminal 204 can normally exchange data via the line conversion device 203.

(ii) Operation of the entire system Here, it is assumed that the controller 201 is a master controller controlling the PO3 terminal 204, and the controller 202 is a backup controller.

:]7tl:) -Ra20H;! , inquires whether there is new data in the PO3 terminal 204.

The PO3 terminal 204 responds to the inquiry from the controller 201 and, if there is new data, transmits that data.

The controller 201 receives new data from the PO3 terminal 204 and sends it to the disk device 211 to update sales information.

On the other hand, the controller 202 monitors whether the controller 201 periodically makes inquiries to the PO8 terminal 204.

If the controller 201 makes an inquiry to the PO3 terminal 204 within a certain period, the controller 202
The response from the O3 terminal 204 is received (intercepted) and sent to the disk device 221 to update the sales information.

If the controller 201 does not make an inquiry to the PO8 terminal 204 within a certain period, the controller 201
2 becomes a master controller instead of the controller 201 and controls the PO3 terminal 204.

(2) Summary of the Embodiment In this way, the line conversion device 203 has the downlink high impedance detection circuit 231. The upstream high impedance detection circuit 233 detects the impedance of the upstream line of the 4-wire line and the impedance of the 2-wire line, respectively, and
48, 25B. As a result, controller 2
01.202 can send and receive data via the line conversion device 203 and the PO8 terminal 204 connected to the four-wire line through the two-wire line.

A controller 201 that communicates via a two-wire line.
When one of the controllers 202 (for example, the controller 201) becomes a master controller and controls the PO3 terminal, another controller (for example, the controller 202)
) can share sales information using an overhearing method that monitors and intercepts communication between the controller 201 and the PO3 terminal 204, thereby making it possible to prepare in case an abnormality occurs in the controller 201.

■1 Bad way of deforming the invention In addition, in the embodiment of the present invention described above, a PO3 terminal control system was considered, but the terminal device is not limited to a PO8 terminal, but also a terminal connected to a 4-wire line. It can be applied to any number of terminals.

In addition, in "1. Correspondence between Examples and FIG. 1",
Although the correspondence between the present invention and the embodiments has been described, those skilled in the art can easily imagine that the present invention is not limited to this and that there are various modifications.

〔Effect of the invention〕

As described above, according to the present invention, other control devices listen in on communication between a terminal device connected to a four-wire line and one control device, thereby sharing information from the terminal device. can do. Therefore, a plurality of control devices can be connected in parallel to the line, and it is possible to flexibly respond to changes in the system configuration such as adding a control device. Furthermore, since each of the plurality of control devices is equipped with an information storage means (for example, a disk device), even if an abnormality occurs in the disk device attached to the control device, it can be backed up by another control device. Therefore, it is extremely useful in practical terms.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram of the terminal control system of the present invention, Fig. 2 is a block diagram of the configuration of the terminal control system according to an embodiment of the present invention, and Fig. 3 is line conversion of the embodiment shown in Fig. 2. FIG. 4 is a timing diagram showing the operation of the device, FIG. 4 is an explanatory diagram of the overhearing method, and FIG. 5 is an explanatory diagram of the sharing method. In the figure, 101 is a first control device, 102 is a second control device, 103 is a line converter, 104 is a terminal device, 111 is an information storage means, 121 is an information storage means, 131 is a downlink communication control means, 132 is a downlink Line transmission means, 133 is uplink communication control means, 134 is uplink transmission means, 201.202 is a controller, 203 is a line conversion device, 204.403, 404, 506, 507 is a PO3 terminal, 211.221, 411, 421 , 503 is a disk device, 231 is a downstream high impedance detection circuit, 232 is a downstream transmission circuit, 233 is an upstream high impedance detection circuit, 234 is an upstream transmission circuit, 241.242, 251, 252 are comparators, 243.2
53 is an exclusive OR gate, 244.254 is an inverter, 245.246, 255, 256 is a delay line, 247.2
57 is an AND gate, 248.258 is a driver, 401.501 is a master controller, 402.50
2 is a backup controller, 504 is a disk switching circuit, 505 is a line switching circuit, and 511 and 521 are receivers.

Claims (1)

[Claims] (1) A two-wire line comprising at least one terminal device (104) for communicating data via a four-wire line, and an information storage means (111) for storing data from the terminal device (104). a first control device (101) that communicates with or intercepts the terminal device (104) and accumulates data from the terminal device (104); and a first control device (101) that accumulates data from the terminal device (104). a second control device (102) having an information storage means (121) and communicating with or intercepting the terminal device (104) through a two-wire line to accumulate data from the terminal device (104); ), and the terminal device (10
4), a downlink transmission means (132) for transmitting downlink information directed to the 4-wire line to the downlink of the 4-wire line; a downlink communication control means (131) for detecting downlink information and controlling the downlink transmission means (132); uplink transmission means (134) for transmitting uplink information from the terminal device (104) to a two-wire line;
, detecting uplink information and transmitting the uplink information (134)
A terminal control system comprising: a line conversion device (103) having an uplink communication control means (133) for controlling a four-wire line to a two-wire line;