JPH05266356A - Data transmission equipment - Google Patents

Abstract

PURPOSE:To prevent the double registration of an ID code in a data transmission equipment used in a POS system and the like. CONSTITUTION:Slave sets A-N and a master set are branch-connected to a transmission line 13. The respective slave sets discriminate the presence or absence of the other slave set corresponding to the polling of a terminal number to be registered at the time of registering the terminal number. When the slave set having the same terminal number as the self terminal number exists, it is detached from the transmission line 13 and an abnormal state is informed. Thus, transmission impossibility and system down owing to the double registration of the terminal number can be prevented at the time of transmitting data by the polling selecting system so as to immediately detect the terminal of double registration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission device which is branched and connected to a transmission line and performs data transmission via the transmission line.

[0002]

2. Description of the Related Art Conventionally, in a medium-sized or large-scale store, as shown in FIG. 6, a plurality of POS terminals (slave units) are connected in-line to transmit data to and from a master unit.
The point-of-sales system has been adopted. FIG. 6A shows a master / satellite system, in which a POS terminal 100 used as a master unit is connected to a store controller 103 via a transmission line 14, and this terminal 10
0 to a plurality of terminals 101a to 10 used as slaves
1n are branched and connected via a transmission line 13. Further, FIG. 1B shows a controller system method, in which the controller 1 used as a master unit for the store controller 103.
02, and a plurality of terminals 101a to 101n used as slaves are branched and connected to the controller 102 via the transmission line 13.

In such a system in which a plurality of slave units are branched and connected to the transmission line, a dedicated management table or the like is provided on the master unit side in order to prevent simultaneous data transmission from the plurality of slave units. And manages the child device. A so-called polling / selecting method is adopted as a method for easily performing the function.

[0004]

However, in the conventional data transmission apparatus using the polling / selecting method, two slave units erroneously registered a specific terminal number on the management table (polling table) of the master unit. In this case, the response data is sent from the two slaves to the transmission line at the time of polling the terminal number, and the data collides on the transmission line and transmission cannot be performed. If this happens frequently, the elements that make up the transceiver in the device may be destroyed, resulting in transmission failure and even system down. The same situation occurs when registration is mistakenly made such that a plurality of parent devices exist on one system. In such an abnormal state, it becomes very difficult to determine which terminal (master / slave) has the wrong terminal number, and it takes time to restore.

An object of the present invention is to promptly discriminate a double-registered device without causing a system down even if an ID code such as a terminal number is double-registered as a child device or a parent device. It is to provide a data transmission device capable of performing.

[0006]

A data transmission device according to claim 1 of the present invention is a data transmission device that is branched and connected to a transmission line and performs data transmission via the transmission line. A transmission / reception means for transmitting / receiving data, an ID code registration means for registering an ID code as a slave, and the presence / absence of a polling signal from the master,
And a discriminating means for discriminating the presence or absence of another device that responds to the polling of the ID code registered in the registering device, and when the discriminating device detects an abnormal state in which another device having the same ID code as the self device is detected, The present invention is characterized by comprising switching means for disconnecting the transmitting / receiving means from the transmission line, and notifying means for notifying the occurrence of the abnormal state.

A data transmission device according to claim 2 is
A data transmission device, which is branched and connected to a transmission line and performs data transmission via the transmission line, including a transmission / reception unit for transmitting / receiving data via the transmission line, and an I as a master unit.
When an ID code registration means for registering a D code, a determination means for determining the presence or absence of a polling signal output from another master device to the transmission line, and an abnormal state in which another master device is present are detected by this determination means. Switching means for disconnecting the transmitting / receiving means from the transmission line, and notifying means for notifying occurrence of the abnormal state.

[0008]

In the data transmission apparatus according to the first aspect, the ID code as the slave unit is registered by the ID code registration unit, but the determination unit detects the presence or absence of the polling signal from the master unit, and detects the registered ID code. Determine whether there is another device that responds to polling. If it is determined that there is another device registered with the same ID code as the own device, the switching means disconnects the transmitting / receiving means from the transmission line, and the notifying means notifies the abnormal state.

Due to the above operation, even if the ID code identical to the ID code of the slave unit already branched and connected to the transmission line is mistakenly registered, the slave unit is automatically disconnected from the transmission line and an abnormal state occurs. Be informed.
This prevents the system from going down without falling into the transmission disabled state. In addition, it is possible to quickly identify that the ID code has been double-registered and the device.
The operator will be able to respond quickly.

Further, in the data transmission device according to the second aspect, the discrimination means discriminates the presence or absence of the polling signal transmitted from the other master unit to the transmission line. If a polling signal sent from another base unit is detected, the transmitting / receiving means is disconnected from the transmission line by the switching means,
The abnormal state is notified by the notification means.

With the above operation, even if the ID code of the parent device is erroneously double-registered, the device of the parent device is automatically disconnected from the transmission line and its abnormal state is notified. This prevents the system from going down without falling into the transmission disabled state. In addition, it is possible to promptly determine that the ID code has been double-registered and the device thereof, and the operator can quickly respond.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the data transmission device of the present invention will be described below by taking a POS terminal as an example. In addition, "terminal number" is taken as an example of the "ID code".

First, FIG. 1 shows an example of a case where a terminal number as a certain slave unit is double-registered in the POS system. In FIG. 1, the cordless handset A has a terminal number 01, and the cordless handset B has a terminal number of 01.
02 is registered as the terminal number, and 31 is registered as the terminal number for the slave N. In addition, 00 is registered as the terminal number in the parent machine. In this state, when a new cordless handset C is used by connecting it to the transmission line 13, if the terminal number 02 is mistakenly registered, the terminal number 02 of the cordless handset B and the double registration state will be entered. With the function of, the cordless handset C, which is erroneously doubly registered, is disconnected from the transmission line 13.

FIG. 2 shows an example in which the terminal number as the master unit is double registered. When 00 is registered as the terminal number of the slave N as in this example, the dual registration state of the master is determined, and the slave N is automatically disconnected from the transmission line 13.

Next, FIG. 4 shows an example of the polling signal sent from the master unit to the transmission line and the response signal of each slave unit in response to the polling signal. The base unit has terminal numbers 01 to 31 in the cycle indicated by T.
Until then, polling signals are sequentially transmitted and this is repeated. The slave unit detects the polling signal on the transmission line and responds to the polling of the terminal number registered in its own terminal device.

FIG. 3 is a schematic block diagram showing a POS system constructed by branching and connecting POS terminals according to an embodiment of the present invention. In FIG. 3, the POS system includes, for example, 32 Ps that are branched and connected to the transmission line 13 including the master unit.
The OS terminal 1 is included. For example, a store controller is connected to the transmission line 13.

The POS terminal 1 includes a main CPU 2, a transmission sub CPU 3, a watchdog timer (WD in the figure).
T) 4, transceiver section 5, display section 8, peripheral interface 9, ROM 10, RAM 11 and keyboard 1
Including 2 and.

A program to be executed by the main CPU 2 is written in the ROM 10 in advance. RAM11 is I
The D code is stored, and the transmitted data and the received data are temporarily stored. The keyboard 12 inputs an ID code and the like. The main CPU 2 executes a program previously written in the ROM 10 to control the operation of the peripheral interface 9. The peripheral interface 9 inputs and outputs between the transmission sub CPU 3 and the main CPU 2. The transceiver unit 5 transmits and receives data via the transmission line 13, and includes a transceiver 6 and a switch element 7. The transmission sub CPU 3 controls the operation of the transceiver unit 5. When there is data to be transmitted when the polling signal is received from the transmission line 13, the transmission sub CPU 3 outputs a gate enable signal to the transceiver 6 in order to enable data transmission from the POS terminal 1. To do. The transmission data is output from the transmission sub CPU 3 to the transmission line 13 via the transceiver 6. Received data is received by a route that is the reverse of this route. Watchdog timer 4 is the main CPU 2
Also, the operation of the transmission sub CPU 3 is monitored. Display 8
Notifies the abnormal state when the ID code is double-registered, and also indicates the abnormal state when the watchdog timer 4 becomes abnormal in the operation of the main CPU 2 or the transmission sub CPU 3. Notify me.

Next, FIG. 5 is a flowchart showing the main part of the processing procedure of each POS terminal.

If the POS terminal is in the terminal number registration mode at the start of operation, it first reads the terminal number input from the keyboard (n1 → n2). As will be described later, if the terminal number is 00, it operates as a master unit, and if it is 01 to 31, it operates as a slave unit. Numerical value entered from the keyboard is 01-3
If it is in the range of 1, it is regarded as a slave unit, and it is monitored whether or not there is a device that responds to polling of the terminal number (n
3 → n4 → n5). That is, the first polling does not return a response from its own terminal, but checks whether another terminal returns a response. If there is no other terminal that responds to the poll, complete the registration of that terminal number,
The operation as a slave is started (n6 → n7). If another terminal responding to the polling of the registered terminal number is detected, the switch element 7 shown in FIG. 3 is opened to disconnect the terminal from the transmission line (n6 → n11). Thereafter, the display unit 8 is used to notify that there is an abnormality due to double registration of the terminal number (n12). If 00 is registered as the terminal number, it is determined whether or not a polling signal from another master exists on the transmission line (n3 → n).
8 → n9). As shown in FIG. 4, the polling signal is sent to the transmission line in a cycle of a fixed time T, so if there is a normal polling signal within this time T, it should be detected as the dual registration state of the master unit. You can If the master unit is in the double registration state, the terminal registered as the master unit is disconnected from the transmission line and an abnormality is notified (n9 → n11 →
n12). If there is no polling signal from other base unit,
The registration of the terminal number is completed, and the operation as the master unit is started (n9 → n10).

In the embodiment described above, the function of disconnecting from the transmission line at the time of double registration and the dual registration of the terminal number as the slave unit and the double registration as the master unit are determined,
Since it has a function of disconnecting from the transmission line at the time of double registration, the same terminal can be selectively used for both the master unit and the slave unit.

[0022]

According to the present invention, when the ID code registered in the data transmission device is the same as the ID code of another data transmission device already registered as a slave, it is also registered in the data transmission device. If the ID code to be generated is the same as the ID code of another data transmission device already registered as the master unit, this is automatically determined as an abnormal state, and the data transmission device is disconnected from the transmission line when the abnormality occurs. In addition, the abnormal state is notified. For this reason,
It is possible to prevent transmission failure and system down due to data collision, and it is possible to quickly identify the dually registered data transmission device. Moreover, since the control and management of the device can be easily and error-free with a simple structure, it is not necessary to deal with the conventional large-scale master device and controller, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a POS system showing a state of double registration of a terminal number as a slave unit.

FIG. 2 is a block diagram of a POS system showing a state of double registration of a terminal number as a master unit.

FIG. 3 is a schematic block diagram of a POS system showing an internal configuration of a POS terminal.

FIG. 4 is a diagram showing a relationship between a polling signal and a response signal.

FIG. 5 is a flowchart showing a main part of a processing procedure of a POS terminal.

FIG. 6 is a block diagram showing a configuration of a general POS system.

Claims (2)

[Claims] 1. A data transmission device branch-connected to a transmission line and transmitting data via the transmission line, a transmitting / receiving means for transmitting / receiving data via the transmission line, and an ID for registering an ID code as a slave unit. Code registration means, a determination means for detecting the presence / absence of a polling signal from the master unit, and determining the presence / absence of another device that responds to the polling of the ID code registered in the registration means; A data transmission device comprising switching means for disconnecting the transmitting / receiving means from the transmission line when an abnormal state in which another device having the same ID code exists is detected, and informing means for informing the occurrence of the abnormal state. 2. A data transmission device, which is branched and connected to a transmission line and performs data transmission via the transmission line, and transmitting / receiving means for transmitting / receiving data via the transmission line, and an ID for registering an ID code as a master unit. Code registration means, determination means for determining the presence or absence of a polling signal output from another master to the transmission line, and when this determination means detects an abnormal state in which another master exists, the transmission / reception means is A data transmission device comprising: switching means for disconnecting from a transmission line; and notifying means for notifying occurrence of the abnormal state.