JPH10190670A - Radio data communication system and its doubling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To actualize doubling which can secure communication paths of respective POS terminals and a server even if the line connecting the server to a radio base station is disconnected. SOLUTION: Servers S1 and S2 monitor each other and, once one server detects abnormality of the other server, functions as substitute for the other server. Radio base stations BUS1 and BUS2 stop radio communicating operation if a communication with the server through a wire becomes abnormal to disable the radio communication with the radio-connected POS terminal. Then POS terminals TM1 and TM2 switch radio communication partners from main radio base station to a subordinate radio base station if a radio communication with the main radio base station communicating with their slave radio stations is disabled. The main radio base station and subordinate radio base are radio base stations which are connected to different host equipments by wires.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless POS (Po
The present invention relates to a wireless data communication system such as an int of sales (point-of-sale information management) system and a duplexing method thereof.

[0002]

2. Description of the Related Art In general, a wireless POS system allows a wireless base station to be connected to a host device such as a computer by wire, and allows a plurality of POS terminals controlled by the host device to wirelessly communicate with the wireless base station. Wireless stations are provided, and data communication between the host device and each POS terminal is performed wirelessly. For example, when sales registration of a customer-purchased product is performed at a certain POS terminal, an inquiry message of product data is wirelessly transmitted from a wireless slave station of the POS terminal. Then, this message is received by the wireless base station and input to the higher-level device through wired communication. As a result, the product data such as the unit price and the product name of the product is given from the higher-level device to the wireless base station, and wirelessly transmitted to the POS terminal of the inquiry source. In the POS terminal receiving the product data at the wireless slave station, the sales registration processing of the product sales data is performed based on the product data.

In such a wireless POS system, if a failure occurs in a higher-level device or communication between the higher-level device and the POS terminal becomes abnormal, product registration at the POS terminal results in an error. Since there is a problem that the accounting operation with the shopper cannot be performed, the host device and the wireless base station are duplicated.

[0004] Specifically, a higher-level device is a pair of a first higher-level device and a second higher-level device, and a plurality of wireless base stations are connected to each higher-level device by wires, respectively. A switch is interposed. And each upper device,
Each other monitors the operation of each other, and when an abnormality of the other higher-level device is detected, the line switch is controlled so that each wireless base station connected to the other higher-level device is connected to itself. By doing so, the POS terminal under the control of the host device in which the abnormality has occurred can perform data communication with the normal host device, and does not hinder business.

[0005] Further, an alternative radio base station is determined in advance for each radio base station. Then, each higher-level device monitors the state of the wireless base station connected by wire, and when an abnormality of a certain wireless base station is detected, the function of the wireless base station is replaced by an alternative wireless base station for the wireless base station.
By doing so, the POS terminal wirelessly connected to the abnormal radio base station continues to perform data communication with the higher-level device via the alternative radio base station. Absent.

[0006]

However, even in the conventional wireless data communication system in which the host device and the radio base station are duplicated as described above, the line connecting the host device and the radio base station is disconnected. In this case, if the wireless base station and the alternative wireless base station are connected downstream from the disconnection point, all the POS terminals wirelessly connected to the wireless base station and the alternative wireless base station are disabled. There was a problem.

Accordingly, the present invention provides a communication path between each controlled terminal and a higher-level device not only when a failure occurs in a higher-level device or a radio base station but also when a line connecting the higher-level device and the radio base station is disconnected. To provide a wireless data communication system capable of securing the same and a duplex method thereof.

[0008]

According to a first aspect of the present invention, a plurality of controlled terminals controlled by the higher-level devices are connected to different wireless base stations by at least two higher-level devices. In a wireless data communication system in which each wireless base station capable of wireless communication with each wireless base station is provided, and data communication between a higher-level device and each controlled terminal is performed by radio, A means for monitoring each other and detecting the abnormality of the other higher-level device by itself to substitute the function of the other higher-level device is provided. In addition, when a wired communication with the higher-level device becomes abnormal, the wireless base station connected to the at least one higher-level device stops the wireless communication operation and disables the wireless communication with the wirelessly-connected wireless slave station. A means for performing this is provided. Further, each controlled terminal has information on one main radio base station that performs radio communication with its own radio slave station and at least one sub radio base that switches when radio communication with the main radio base station is disabled. Means for storing information about the station, and means for switching a wireless communication partner from the main radio base station to the sub radio base station when radio communication with the main radio base station is disabled, and The sub-radio base stations are radio base stations that are wired to different higher-level devices.

The invention described in claim 2 of the present application is the above-described claim 1.
In the invention described above, the wireless base station is provided with means for detecting an abnormality in wired communication between the host device and the wireless base station. According to a third aspect of the present invention, in the first aspect of the present invention, means for detecting an abnormality in wired communication between the higher-level device and the wireless base station is provided in the higher-level device. This is to notify the wireless base station connected by wire of the presence of the abnormality. According to a fourth aspect of the present invention, in the first aspect of the present invention, when an abnormality of a higher-level device occurs, before the means for detecting an abnormality of the wired communication between the higher-level device and the wireless base station is activated, the other device is activated. The upper-level device detects an abnormality and the means for substituting the function of the higher-level device operates preferentially.

[0010] The invention according to claim 5 of the present application provides at least 2
A different radio base station is connected to each of the higher-level devices by wire, and a plurality of controlled terminals controlled by the higher-level devices are each provided with a radio slave station capable of performing radio communication with each radio base station. This is a method of duplexing a wireless data communication system in which data communication between a device and each controlled terminal is performed wirelessly, and when each higher-level device monitors each other and detects an abnormality in the other higher-level device, the higher-level device detects itself. The wireless base station that substitutes for the function of the other higher-level device and that is wired to at least one of the higher-level devices stops the wireless communication operation when the wired communication with that higher-level device becomes abnormal, and the wirelessly connected wireless device. Disables wireless communication with the base station, and each controlled terminal disconnects information about one main wireless base station that performs wireless communication with its own wireless slave station and disables wireless communication with the main wireless base station. And information about at least one sub radio base station to be changed is stored in advance, and when radio communication with the main radio base station is disabled, the radio communication partner is switched from the main radio base station to the sub radio base station, and The base station and the sub-radio base station are radio base stations connected to different higher-level devices by wire, so that data communication between the higher-level device and each controlled terminal is duplicated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment in which the present invention is applied to a wireless POS system in which a wired line connecting a server and a wireless base station is a bus type will be described with reference to FIGS.

FIG. 1 shows a wireless P in the first embodiment.
FIG. 1 is an overall view of an OS system. As a higher-level device having a product data file storing product data such as a unit price and a product name of each product and a sales totalization file for totaling sales data of each product sold and registered at each POS terminal, etc. , A first server S1 and a second server S2. And
The first server S1 is connected to a first wireless base station BSU1-1 and a second wireless base station BSU1-2 by a bus-type communication path L1 via a line switch CH. Server S
The third wireless base station BSU2-1 and the fourth wireless base station B are connected to the second wireless base station B2 via a bus-type communication path L2 through the same line switch CH.
SU2-2 is connected.

Further, as controlled terminals for performing sales registration processing of sales data of each product under the control of the servers S1 and S2, 20 POS terminals TM1-1 to TM10 and TM2-1 to 10 are provided. And each of the POS terminals TM1-1 to TM10, TM2
-10 to POS terminal TM1-1-5, POS terminal TM1
-6 to 10, POS terminal TM2-1 to 5, POS terminal TM2-6
4 groups G1, G2, G each with 5 units like ~ 10
3 and G4, and the five POS terminals TM1-1 to 5 belonging to the first group G1 are connected to the first wireless base station BSU1-1.
And the five POS terminals TM1-6 to TM10 belonging to the second group G2 are connected to the second wireless base station BSU1-2 by the wireless line R2 and belong to the third group G3. The five POS terminals TM2-1 to TM5-5 are connected to the third radio base station BSU2-1 by the radio line R3, and the five POS terminals TM2-6 to TM4-6 belonging to the fourth group G4 are connected.
10 is connected to a fourth wireless base station BSU2-2 by a wireless line R4.

The first server S1 and the second server S
2 has a common hardware configuration, and as shown in FIG.
PU (Centrl Processing Unit) 11, ROM (Read O
nlyMemoly) 12 and RAM (Random Access Memoly)
The control unit is constituted by 13 computer-mounted components. Further, a server interface 14 for inputting a signal from the other server connected via the inter-server monitoring signal line SV, and a wireless base station connected via the bus-type communication path L (L1 or L2). A communication controller 15 for controlling data communication and a line switch signal C
It has an I / O port 16 for sending to H. further,
An FDD (Floppy Disk Dr.) for reading and writing data stored in a floppy (registered trademark) disk 17 which is a storage medium readable by a computer.
ive) 18, an external storage device of an HDD (Hard Disk Drive) 19 for reading and writing data from and to a hard disk forming a product data file, a sales summary file, and the like, and input / output of a keyboard 20, a printer 21, a display 22, and the like. The system includes controllers 23 to 27 for controlling the respective devices.
3, server interface 14, communication controller 1
5, the I / O port 16 and each of the controllers 23 to 27 are connected by a bus line 28 such as an address bus and a data bus.

The first to fourth radio base stations BSU1-1, BSU1-1,
The BSU1-2, BSU2-1, and BSU2-2 have a common hardware configuration. As shown in FIG.
2 and a computer-mounted component of the RAM 33 constitute a control unit. Further, the bus-type communication path L (L1
Or a communication controller 34 for controlling data communication with a server connected by L2), for example, a wireless circuit 35 for performing wireless data communication by a 2.4 GHz band spread spectrum method, and the like.
32, a RAM 33, a communication controller 34, and a wireless circuit 35 are connected to a bus line 3 such as an address bus and a data bus.
6 is connected. As shown in FIG. 4, each memory of the error counter EC and the delay set time E0 is formed in the RAM 33.

Each of the POS terminals TM1-1 to TM10, TM2-1
10 have the same hardware configuration, and as shown in FIG.
The control unit is constituted by computer-mounted components such as the CPU 41, the ROM 42, and the RAM 43. A wireless interface 44 is mounted, and a wireless slave station 45 is connected to the wireless interface 44. Further, an external storage device such as an FDD 48 for reading and writing data stored in the floppy disk 46 and an HDD 49 for reading and writing data to and from the hard disk, a keyboard 50, a scanner 51, a drawer 52, and a printer 5
3, controllers 55 to 61 for controlling POS terminal devices such as the display 54, respectively.
1, the ROM 42, the RAM 43, the radio interface 44, and the controllers 55 to 61 are connected by a bus line 62 such as an address bus and a data bus.

The RAM 43 stores its own wireless slave station 45.
Forming a base station information memory 63 for storing information about one main radio base station that performs radio communication with the base station and information about one sub radio base station that is switched when radio communication with the main radio base station is disabled. doing. Here, each of the POS terminals TM1-1 to TM5 belonging to the first group G1 is shown in FIG.
As shown in (a), the first server S as a main radio base station
The information on the first radio base station BSU1-1 connected to the first radio base station 1 is stored, and the information on the third radio base station BSU2-2 connected to the second server S2 as the sub radio base station is stored. Each POS terminal TM belonging to the second group G2
1-6 to 10 are second radio base stations BS connected to the first server S1 as main radio base stations as shown in FIG.
The information on U1-2 is stored, and the secondary
Fourth radio base station BSU2-4 connected to the server S2 of
The information about is stored.

Each of the POS terminals TM2-1 to TM5 belonging to the third group G3 is, as shown in FIG. 6C, a third radio base station BSU2 connected to the second server S2 as a main radio base station. -1 and stores the first radio base station BSU connected to the first server S1 as a sub radio base station.
The information about 1-2 is stored. Each POS terminal TM2-6 to 10 belonging to the fourth group G4 relates to the second wireless base station BSU2-2 connected to the second server S2 as a main wireless base station as shown in FIG. The information is stored, and information on the second radio base station BSU1-4 connected to the first server S1 as the sub radio base station is stored.

The CPUs 11 of the two servers S1 and S2 monitor each other using the inter-server monitoring signal line SV. Here, the CPU 11 of the first server S1
When detecting an abnormality of the second server S2 based on the signal on the inter-server monitoring signal line SV, it turns on the line switching signal SL1, disconnects the second server S2 from the communication path L2, and disconnects the communication path L2 from the first communication path L2. Connect to server S1. And the first
Server S1 controls each unit so that the function of the second server S2 is substituted.

On the other hand, the CPU 11 of the second server S2
The first server S1 is operated by the signal of the inter-server monitoring signal line SV.
When the abnormality is detected, the line switching signal SL2 is turned on,
The first server S1 is disconnected from the communication path L1, and the communication path L1 is connected to the second server S2. Then, the second server S2 controls each unit so as to replace the function of the first server S1.

The four radio base stations BSU1-1, BSU1-1,
CPU 31 of BSU1-2, BSU2-1, BSU2-2,
Whether or not the lines to the servers S1 and S2 connected via the bus-type communication paths L1 and L2 are normally connected is periodically checked by the following program processing. That is, as shown in FIG. 7, the CPU 31 transmits a packet message for confirming wired communication to the first server S1 or the second server S2 connected via the bus-type communication paths L1 and L2 via the communication controller 34 [ p1]. In response,
When the response messages from the corresponding servers S1 and S2 are received within the predetermined time [YES in p2], if the error counter memory EC on the RAM 33 is reset to “0”, [p
3], waiting for a certain delay time to elapse [p
4]. Then, when a certain delay time has elapsed, the flow returns to p1, and the packet message for confirming the wired communication is transmitted again to the corresponding servers S1 and S2.

As a result of the transmission of the packet message for confirming the wired communication, the corresponding servers S1, S
If the response message from the server 2 cannot be received [YES in p5], since the communication path or the server has an abnormality, the count value of the error counter memory EC is incremented by "1" [p6]. ]. Thereafter, the count value of the error counter memory EC and the RAM 33
The value is compared with the set value of the delay set time memory E0. If the count value has not reached the set value [NO in p7], the process waits for a certain delay time to elapse [p4]. Then, when a certain delay time has elapsed, the flow returns to p1, and the packet message for confirming the wired communication is transmitted again to the corresponding servers S1 and S2. On the other hand, when the count value of the error counter memory EC has reached the set value of the delay set time memory E0 [YES in p7], the wireless communication function of the wireless circuit 35 is stopped [p8], and this confirmation processing is performed. To end.

Further, each of the 20 POS terminals TM1-1
CPUs 41 to 10 and TM2-1 to 10
The radio links R1 to RSU1 to the radio base stations BSU1-1, BSU1-2, BSU2-1, and BSU2-2 set as the radio communication counterparts based on the information on the main radio base station stored in the base station information memory 63 on the base station 3. Whether or not R4 is normally connected is periodically checked by the following program processing. That is, as shown in FIG. 8, the CPU 41 transmits a packet message for wireless communication confirmation from the wireless slave station 45 to the wireless base stations BSU1-1, BSU1-2, BSU2-1, BSSU corresponding to the main wireless base station.
It transmits to U2-2 wirelessly [q1]. In response,
Radio base stations BSU1-1, BSU1 corresponding within a predetermined time
-2, when response messages from BSU2-1 and BSU2-2 are received [YES in q2], the process waits for a certain delay time to elapse [q3]. Then, when a certain delay time has elapsed, the flow returns to q1, and the packet message for wireless communication confirmation is again transmitted to the wireless base stations BSU1-1 and BSU1 corresponding to the main wireless base station.
-2, BSU2-1 and BSU2-2 are transmitted by radio.

As a result of transmitting the packet message of the wireless communication confirmation, the corresponding wireless base station BS even after a predetermined time has elapsed.
When the response message from U1-1, BSU1-2, BSU2-1, or BSU2-2 cannot be received [YES in q4],
Since an abnormality has occurred in the radio base station, information on the sub radio base station is read from the base station information memory 63 [q5]. Then, the wireless communication partner is switched to the sub wireless base station [q6]. Thereafter, the process returns to q1, and transmits a radio communication confirmation packet message to the radio base stations BSU1-1, BSU1-2, BSU2-1, and BSU2-2 corresponding to the secondary main radio base station by radio.

In the wireless POS system according to the first embodiment configured as described above, for example, when the first server S1 fails and the second server S2 detects this failure, the second server S2 detects the failure. Line switching signal S from server S2
L2 is turned on. As a result, the first server S1 is disconnected from the communication path L1, and the communication path L1 is connected to the second server S2. As a result, the two radio base stations BSU1-1 and BSU1-2 connected to the communication path L1 become the two radio base stations BSU2-1 and BSU1-2 connected to the communication path L2.
As in the case of 2-2, the second server S2 is connected to the second server S2 by wire, and communication with the server is continued.

Also, for example, if the second server S2 fails,
If this failure is detected by the first server S1, the first server
Line switching signal SL1 from the server S1 is turned on.
As a result, the second server S2 is disconnected from the communication path L2, and the communication path L2 is coupled to the first server S1. As a result, the two radio base stations BSU2-1 and BSU2-2 connected to the communication path L2 are connected to the first radio base stations BSU1-1 and BSU1-2 similarly to the two radio base stations BSU1-1 and BSU1-2 connected to the communication path L1.
Is connected to the server S1 by wire, and the state in which communication with the server S1 is possible is continued. According to the above operation, when a failure occurs in one of the servers, the other server can replace the function of the failed server, so that redundancy is achieved for the failure of the server.

Next, when both the first and second servers S1 and S2 are normal, for example, the first radio base station B
When US1-1 breaks down and wireless communication becomes impossible,
In the POS terminals TM1-1 to TM5 of the group G1 having the first wireless base station BUS1-1 as a main wireless base station, the packet message for wireless communication confirmation is transmitted to the first wireless base station BUS1.
The wireless communication partner is automatically switched from the primary wireless base station to the secondary wireless base station because the wireless communication is transmitted to -1 but the response to the wireless communication cannot be received. As a result, the PO of this group G1
The S terminals TM1-1 to TM5 can perform wireless communication with the third wireless base station BUS2-1, and the third wireless base station BUS2-1.
, Data communication with the second server S2.

Similarly, for example, the second radio base station BUS1
-2 fails and wireless communication becomes impossible, the POS terminals TM1-6 to 10 of the group G2 having the second wireless base station BUS1-2 as a main wireless base station automatically perform wireless communication. The communication partner is switched to the secondary wireless base station, and data communication is performed with the second server S2 via the fourth wireless base station BUS2-2. Also, for example, the third wireless base station BUS2
In the case where the wireless communication becomes impossible due to the failure of -1, the POS terminals TM2-1 to 5 of the group G3 having the third wireless base station BUS2-1 as the main wireless base station automatically perform wireless communication. The communication partner is switched to the sub wireless base station, and data communication is performed with the first server S1 via the first wireless base station BUS1-1.

Further, for example, the fourth radio base station BUS2-2
If wireless communication is disabled due to a failure,
POS terminals TM2-6 to 10 of group G4 having the wireless base station BUS2-2 as the primary wireless base station automatically switch the wireless communication partner to the secondary wireless base station, and
Data communication with the first server S1 is performed via US1-2. According to the above operation, when a failure occurs in any one of the wireless base stations, the POS terminal having the wireless base station as the main wireless base station transmits the wireless communication partner to the wireless base station whose secondary wireless base station is set as the secondary wireless base station. Switching is performed automatically, and data communication with a normal server is performed via the sub-radio base station, so that redundancy can be achieved even when the radio base station fails.

Next, the first and second servers S1, S2 and the first to fourth radio base stations BUS1-1, BUS1-2, BU
When both S2-1 and BUS2-2 are normal, for example, the first server S1 and the first and second wireless base stations BU
When a disconnection occurs at point A (see FIG. 1) of the communication path L1 connecting S1-1 and BUS1-2, the first and second wireless base stations BUS1-1 and BUS1-2 have: The wireless communication function is stopped because a packet message for confirming the wired communication is transmitted to the first server S1, but a response to the packet message cannot be received. Thereby, the first and second radio base stations B
POS terminals TM1 belonging to groups G1 and G2 with US1-1 and BUS1-2 as main radio base stations, respectively.
-1 to 5 and the POS terminals TM1 to 6 to 10 cannot automatically receive the response to the packet message of the wireless communication confirmation, so that the wireless communication partner is automatically switched to the sub wireless base station as described above, and the POS terminal of the group G1 The TM1-1 to TM5-1 perform data communication with the second server S2 via the third wireless base station BUS2-1, and the POS terminals TM1-6 of the group G2.
10 perform data communication with the second server S2 via the fourth wireless base station BUS2-2.

Further, for example, when a disconnection occurs at a point B (see FIG. 1) of a communication path L2 connecting the second server S2 and the third and fourth wireless base stations BUS2-1 and BUS2-2. Are the third and fourth wireless base stations BUS2-1, BUS2-2
In, the wireless communication function is stopped because a packet message for confirming the wired communication is transmitted to the second server S2 but a response to the packet message cannot be received. As a result, this third
POS terminals TM2-1 to TM5-5 and POS terminals TM2-6 belonging to groups G3 and G4 with the fourth radio base stations BUS2-1 and BUS2-2 as main radio base stations, respectively.
In Nos. 10 to 10, the wireless communication partner is automatically switched to the sub wireless base station as described above since the response to the packet message of the wireless communication confirmation cannot be received, and the PO of the group G3 is changed.
The S terminals TM2-1 to TM5 perform data communication with the first server S1 via the first wireless base station BUS1-1, and
4 POS terminals TM2-6 to 10 are connected to the second wireless base station BUS.
Data communication is performed with the first server S1 via 1-2.

According to the above operation, when a disconnection occurs in one of the communication paths, the POS terminal having the wireless base station connected to the communication path on the side where the disconnection has occurred as a wireless communication partner has a problem. Since the communication path with the server is secured with the wireless base station connected to the other communication path in which the disconnection does not occur automatically as the wireless communication partner, redundancy is achieved even for the disconnection of the communication path. .

When the first server S1 breaks down, for example, the wireless base stations BUS1-1 and BUS1-2 connected to the server S1 via the communication path L1 transmit the packet message for confirming the wired communication. The wireless communication function is stopped because a response cannot be received. As a result, the wireless base stations BUS1-1 and BUS1-2 are set as main wireless base stations.
The OS terminals TM1-1 to TM1-5 and TM1-6 to TM10 communicate with the radio base stations BUS2-1 and B-2 whose radio communication partners are set as sub radio base stations.
Switch to US2-2. As a result, the radio base stations BUS2-1 and BUS2 connected to the communication path L2 despite the fact that the communication path L1 and the radio base stations BUS1-1 and BUS1-2 are not abnormal.
There is a concern that the number of POS terminals under the management of -2 may increase and the performance of the system may decrease. The same applies to the case where the second server S2 has failed, and the wireless base station BUS1 connected to the communication path L1 despite the fact that the communication path L2 and the wireless base stations BUS2-1 and BUS2-2 are not abnormal. -1,
The number of POS terminals under the control of the BUS1-2 may increase, and the performance of the system may decrease.

Therefore, in the first embodiment, the first to fourth wireless base stations BUS1-1, BUS1-2, BUS1-2,
The BUS2-1 and BUS2-2 require a delay set time E0 to detect an abnormality in the line confirmation processing with the server, and the line is switched to the other server due to the failure of the server. By setting the time longer than the required time until the communication is stabilized, the function of the failed server is replaced with a normal server until the delay set time E0 elapses, and the substitute server responds to the packet message of the wire communication confirmation from the substitute server. A response is returned and the error counter EC is cleared.

As a result, when a server malfunctions, the other server detects the malfunction and substitutes the function of the server before the means for detecting the malfunction of the wired communication between the server and the radio base station operates. Means to work preferentially,
The failure of one server does not stop the wireless communication function of the wireless base station connected to that server, and there is no concern that the load on the wireless base station connected to the other server will increase.

Next, a second embodiment in which the present invention is applied to a wireless POS system in which a wired line connecting a server and a wireless base station is a loop type will be described with reference to FIGS. . The first and second servers S1, S
2, the first to fourth wireless base stations BUS1-1, BUS1-2,
BUS2-1, BUS2-2 and each POS terminal TM1-1-1
0, TM2-1 to 10 are the same as those in the first embodiment, and the description thereof is omitted by using FIGS. 2 to 6 in common.

FIG. 9 shows a wireless P in the second embodiment.
FIG. 2 is an overall view of an OS system, and portions common to FIG. 1 are denoted by the same reference numerals. That is, it has a first server S1 and a second server S2 functioning as higher-level devices. Then, the first wireless base station BS is connected to the first server S1 through the loop communication path Q1 via the line switch CH.
U1-1 and the second wireless base station BSU1-2 are connected in order, and the third wireless base station BSU2 is connected to the second server S2 by the loop communication path Q2 via the same line switch CH. -1
And the fourth wireless base station BSU2-2 are sequentially connected.

Then, the POS terminals TM1-1 to POS1-1 belonging to the first group G1 with respect to the first wireless base station BSU1-1.
5 via a radio line R1, and a second radio base station BSU1
-2 POS terminal TM belonging to the second group G2
1-6 to 10 are connected by a radio line R2, and a third radio base station B
The POS terminals TM2-1 to TM5 belonging to the third group G3 are connected to the SU2-1 by the radio line R3, and the Ps belonging to the fourth group G4 are connected to the fourth radio base station BSU2-2.
OS terminals TM2-6 to TM10 are connected by a radio line R4.

The CPUs 11 of the two servers S1 and S2 monitor each other using the inter-server monitoring signal line SV, as in the first embodiment. here,
When the CPU 11 of the first server S1 detects an abnormality of the second server S2 based on the signal on the inter-server monitoring signal line SV, the CPU 11 turns on the line switching signal SL1 and turns on the second server S2.
Is separated from the communication path Q2, and the communication path Q2 and the other communication path Q1 are combined into one loop to form the first server S
Bind to 1. Then, the first server S1 controls each unit so as to replace the function of the second server S2.

On the other hand, the CPU 11 of the second server S2
The first server S1 is operated by the signal of the inter-server monitoring signal line SV.
When the abnormality is detected, the line switching signal SL2 is turned on,
The first server S1 is disconnected from the communication path Q1, and the communication path Q1 and the other communication path Q2 are combined into a single loop and connected to the second server S2. Then, the second server S2 controls each unit so as to replace the function of the first server S1.

The CPUs 11 of the first and second servers S1 and S2 are connected to the wireless base stations BUS1-1, BUS1-2 and BUS2- connected via loop communication paths Q1 and Q2.
1. Whether or not the line to BUS2-2 is normally connected is periodically checked by the following program processing. That is, as shown in FIG. 10, the CPU 11 transmits a packet message of polling to the loop communication paths Q1 and Q2 connected to the communication controller 34 [r1]. here,
The polling packet message transmitted from the first server S1 includes the loop-type communication path Q1 and the wireless base stations BUS1-1, BUS1-1.
When the BUS1-2 is normal, the communication path returns to the first server S1 after making a round on the communication path Q1, and the polling packet message transmitted from the second server S2 is transmitted to the loop-type communication path Q2 and the wireless base station BUS2-. 1, when BUS2-2 is normal, returns to the second server S2 after making one round of the communication path Q2.
When U11 detects the return of the polling packet message within the predetermined time [YES in r2], it waits for a certain delay time to elapse [r3]. Then, when a certain delay time has elapsed, the flow returns to r1, and the polling packet message is transmitted again to the loop communication paths Q1 and Q2 connected to the communication controller.

As a result of transmitting the polling packet message, if the polling packet message has not returned even after a predetermined time has elapsed [YES in p4], an abnormality has occurred in the communication path or the radio base station. Therefore, a command message of the abnormality notification is transmitted to the loop communication paths Q1 and Q2 [p5]. Thereafter, the flow returns to r1, and the polling packet message is transmitted again to the loop communication path Q1 or Q2.

On the other hand, each of the radio base stations BSU1-1 and BSU1
-2, BSU2-1, and BSU2-2, as shown in FIG. 11, the CPU 31 determines whether a polling packet message or a command message of an abnormality notification can be received within a predetermined time from the servers S1 and S2, which are control stations. Monitoring. Here, if the polling packet telegram is received within the predetermined time [YES in s1], if the error counter memory EC on the RAM 33 is reset to “0” [s2], a certain delay time elapses. [S3]. Then, when a certain delay time has elapsed, it is monitored again whether the next polling packet message or the command message of the abnormality notification can be received within a predetermined time.

If the command message of the abnormality notification is received within the predetermined time [YES in s4], since an abnormality has occurred in the communication path or the radio base station downstream from the self, the wireless circuit 35 Stop the wireless communication function and set [s
8], the message monitoring process ends.

On the other hand, if neither the polling packet message nor the error notification command message can be received within the predetermined time [YES in s5], an error is detected in the communication path upstream of the self, the radio base station or the server. Since the error has occurred, the count value of the error counter memory EC is incremented by "1" [s6]. Thereafter, the count value of the error counter memory EC is compared with the set value of the delay set time memory E0 on the RAM 33. If the count value has not reached the set value, [s7
NO], and waits for a certain delay time to elapse [s
3]. Then, when a certain delay time has elapsed, it is monitored again whether the next polling packet message or the command message of the abnormality notification can be received within a predetermined time. On the other hand, when the count value of the error counter memory EC has reached the set value of the delay set time memory E0 [YES in s7], the wireless communication function of the wireless circuit 35 is stopped [s8], and this message monitoring is performed. The process ends.

Further, each of the POS terminals TM1-1 to TM10, TM2
As in the first embodiment, the CPUs -1 to 10 perform a line connection confirmation process with the wireless base station shown in FIG.

In the wireless POS system according to the second embodiment configured as described above, the servers S1, S
In the case of the second failure, the normal server replaces the function of the failed server, thereby achieving redundancy. Also, in the event of a failure of the wireless base stations BUS1-1, BUS1-2, BUS2-1, BUS2-2, the POS terminal having the failed wireless base station as the main wireless base station automatically sets the wireless communication partner to normal. Switching to a suitable secondary radio base station achieves duplication.

On the other hand, the first and second servers S1, S2 and the first to fourth radio base stations BUS1-1, BUS1-2, BU
When both S2-1 and BUS2-2 are normal, for example, at point A (see FIG. 9) upstream of the first wireless base station BUS1-1 in the loop communication path Q1 of the first server S1. When a disconnection occurs, the first and second wireless base stations BUS1-1 and BUS1-2 cannot receive a polling packet message within a predetermined time, and stop the wireless communication function. As a result, the POS terminals TM1-1 to TM1-5 and the POS terminals TM1-6 to -10 having the first and second wireless base stations BUS1-1 and BUS1-2 as main wireless base stations, respectively.
In, the wireless communication partner is automatically switched to the secondary wireless base station because the response to the packet message of the wireless communication confirmation cannot be received, and the POS terminals TM1-1 to TM5-1 through the third wireless base station BUS2-1. Data communication is performed with the second server S2, and the POS terminals TM1-6 to TM10 perform data communication with the second server S2 via the fourth wireless base station BUS2-2.

For example, if a disconnection occurs at point B (see FIG. 9) downstream of the second radio base station BUS1-2 in the loop communication path Q1, the first and second radios Although the base stations BUS1-1 and BUS1-2 can receive a polling packet message within a predetermined time, the first server S
In No. 1, since the polling packet message is not fed back, the first and second radio base stations BUS1-1 and BUS1-2
Sends a command message for error notification to Thereby, the first and second wireless base stations BUS1-1, BUS1-2
, The wireless communication function stops, and the POS terminal TM1-1
The POS terminals TM1-1 to TM5 and TM1-6 to 10 perform data communication with the second server S2 as described above.

Further, for example, the first wireless base station BUS1-1 and the second wireless base station B in the loop type communication path Q1
The same applies to the case where a disconnection occurs at point C (see FIG. 9) between US1-2 and the first server S1 from the first server S1 to the first and second wireless base stations BUS1-1 and BUS1-2. An error notification command message is sent.

Thus, the first radio base station BUS1-1
In, the wireless communication function stops. Also in the second wireless base station BUS1-2, the wireless communication function is stopped because the polling packet message cannot be received within the predetermined time. As a result, the POS terminals TM1-1 to TM5 and TM1
-6 to 10 operate as described above, and the POS terminals TM1-1 to TM5 and TM1-6 to 10 perform data communication with the second server S2.

The operation described above for the disconnection of the loop-type communication channel Q1 is the same for the disconnection of the second loop-type communication channel Q2, and the third radio base station BUS2-1 is used as the main radio base station. The POS terminals TM2-1 to TM5 are connected to the first wireless base station B.
POS terminals TM2-6 to POS10 having the fourth wireless base station BUS2-2 as a main wireless base station perform data communication with the first server S1 via US1-1, and the second wireless base station BUS1-2.
Will perform data communication with the first server S1 via the.

As described above, in the second embodiment, similarly to the first embodiment, when a disconnection occurs in one of the communication paths, the communication on the side in which the disconnection occurs is performed. In a POS terminal having a wireless base station connected to a path as a wireless communication partner, a wireless base station connected to the other communication path where no disconnection has occurred is automatically switched to a wireless communication partner, so that a connection with a server can be established. The communication path is secured stably, and duplexing is achieved for disconnection of the communication path.

Further, in the second embodiment, each of the radio base stations BUS1-1, BUS1-2, BUS2-
1. The delay setting time E0 is required until the BUS 2-2 determines that there is an abnormality in the line connection with the server from the absence of the polling packet message and stops the wireless communication function. By setting the set time E0 longer than the time required for the line to be switched to the other server due to the failure of the server and the communication to be stabilized, the abnormality of the wired communication between the server and the wireless base station can be achieved when the server is abnormal. Before the means for detecting the error occurs, the other server detects the abnormality and the means for substituting the function of the server operates preferentially, so that the load on the wireless base station connected to the normal server is reduced. It goes without saying that the increase can be prevented.

In the wireless POS system having the loop communication path according to the second embodiment, the server and the wireless base are similar to the wireless POS system having the bus communication path according to the first embodiment. It is also possible to configure so that the wireless base station has means for detecting an abnormality in wired communication with the station. However, in this case, as the number of wireless base stations connected to one communication path increases, the communication traffic on this communication path increases. It is desirable that the server has means for detecting an abnormality in wired communication with the base station, and the server is configured to notify the wired base station of the abnormality when the server detects the abnormality.

In addition, it is needless to say that various modifications can be made without departing from the gist of the present invention, for example, by applying the present invention to a wireless data communication system other than the wireless POS system.

[0057]

As described above in detail, according to the present invention, not only failure of a higher-level device and a radio base station but also disconnection of a line connecting the higher-level device and the radio base station can be prevented. A communication path between the control terminal and the host device can be stably secured, and stable duplexing of the wireless data communication system can be realized.

[Brief description of the drawings]

FIG. 1 shows a wireless PO according to a first embodiment of the present invention.
1 is an overall view of an S system.

FIG. 2 is a block diagram showing a configuration of a main part of a server in the wireless POS system.

FIG. 3 is a block diagram showing a main configuration of a wireless base station in the wireless POS system.

FIG. 4 is a diagram showing a main memory area formed in a RAM of the wireless base station.

FIG. 5 is a block diagram showing a main configuration of a POS terminal in the wireless POS system.

FIG. 6 is a configuration diagram of a base station information memory formed in a RAM of the POS terminal.

FIG. 7 is a flowchart showing base station = server line confirmation processing executed by the CPU of the wireless base station in the wireless POS system.

FIG. 8 is a flowchart showing POS = base station line confirmation processing executed by the CPU of the POS terminal in the wireless POS system.

FIG. 9 shows a wireless PO according to a second embodiment of the present invention.
1 is an overall view of an S system.

FIG. 10 is a flowchart showing server = base station line confirmation processing executed by the CPU of the server in the wireless POS system according to the second embodiment;

FIG. 11 is a flowchart showing base station = server line confirmation processing executed by the CPU of the wireless base station in the wireless POS system according to the second embodiment;

[Explanation of symbols]

S1, S2: first and second servers (upper devices) CH: line switch BUS1-1, BUS1-2: first and second wireless base stations BUS2-1, BUS2-2: third and fourth Wireless base stations TM1-1 to 10, TM2-1 to 10 POS terminals (controlled terminals) L1, L2 bus-type communication paths Q1, Q2 loop-type communication paths EC error counter memory E0 delay setting time memory 63: base station information memory

Claims (5)

[Claims] A wireless base station connected to at least two higher-level devices by a different wireless base station, and a plurality of controlled terminals controlled by the higher-level devices capable of wirelessly communicating with the respective wireless base stations. Set up each slave station,
In a wireless data communication system in which data communication between a higher-level device and each controlled terminal is performed wirelessly, when each higher-level device monitors each other and detects an abnormality in the other higher-level device, the higher-level device itself becomes the other side. Having a means for substituting the function of the higher-level device, the wireless base station wired to at least one of the higher-level devices is stopped and wirelessly connected when the wired communication with the higher-level device becomes abnormal. Each controlled terminal has means for disabling wireless communication with a wireless slave station, and each controlled terminal has information on one main wireless base station that performs wireless communication with its own wireless slave station and wireless communication with the main wireless base station. Means for storing at least one sub-radio base station to be switched when the radio communication becomes disabled, and a radio communication partner being transmitted from the main radio base station to the sub-radio when the radio communication with the main radio base station is disabled. And means for switching to line the base station, and wireless data communication system, characterized in that the main base station and sub base station that a wired connection radio base station to each different host device. 2. The wireless data communication system according to claim 1, wherein the wireless base station has means for detecting an abnormality in wired communication between the host device and the wireless base station. 3. The high-level equipment has means for detecting an abnormality in wired communication between the high-level equipment and the wireless base station, and when the high-level equipment detects the abnormality, notifies the wired base station of the abnormality that there is an abnormality. The wireless data communication system according to claim 1, wherein 4. When an abnormality occurs in a higher-level device, the other higher-level device detects the abnormality and detects an abnormality in the higher-level device before the means for detecting an abnormality in wired communication between the higher-level device and the wireless base station operates. 2. The wireless data communication system according to claim 1, wherein the means for substituting the function operates preferentially. 5. A wireless communication system in which different radio base stations are connected to at least two higher-level devices by wire, and a plurality of controlled terminals controlled by the higher-level devices can perform radio communication with the respective radio base stations. Set up each slave station,
In a wireless data communication system in which data communication between a higher-level device and each controlled terminal is performed wirelessly, when each higher-level device monitors each other and detects an abnormality in the other higher-level device, the higher-level device itself becomes the other side. A wireless base station that substitutes for the function of a higher-level device and that is wired to at least one higher-level device stops radio communication operation when wired communication with that higher-level device becomes abnormal, and establishes a connection with a wirelessly-connected radio slave station. Wireless terminal, and each controlled terminal switches information when one wireless base station that performs wireless communication with its own wireless slave station and wireless communication with the primary wireless base station are disabled. Information on one sub-radio base station is stored in advance, and when radio communication with the main radio base station is disabled, a radio communication partner is switched from the main radio base station to the sub-radio base station.
And the main radio base station and the sub radio base station are characterized in that data communication between the higher-level device and each controlled terminal is duplicated as a radio base station wired to a different higher-level device. Method for a wireless data communication system.