JP3443826B2 - Network system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system in which a host station and a master station are connected to a wired communication LAN, and the master station and a plurality of slave stations are connected to each other via a wireless communication LAN.

[0002]

2. Description of the Related Art Conventionally, a wireless communication LAN is a wired communication LA.
Since the reliability of data communication is lower than that of N, even though it can be used for simple data transmission, it has not yet been used for data transmission between control devices that require high reliability.

However, in recent years, due to the progress of wireless technology such as spread spectrum method and error correction technology, the reliability of data transmission has been remarkably improved, and the network system using the wireless communication LAN is used in the manufacturing site for the following reasons. It has been introduced into and is becoming popular.

To shorten the total lead time. Reduce construction costs. Reduce costs associated with frequent line layout changes. It is difficult to lay a communication cable because the equipment has restrictions such as moving body, rotating body, and operation.

For example, a network system as shown in FIG. 11 has been introduced to the manufacturing site and is becoming popular.

This network system is a remote I
/ O Programmable controller (PL
C) A wired communication LAN composed of a remote I / O network 60 to which the master station 51 and the master station 51 are connected, and a wireless communication LAN for wirelessly transmitting and receiving data between the master station 51 and the slave station 52.

In addition, since the programmable controller 50 needs to repeat cyclic processing within a predetermined time as a communication system to be adopted in the wireless communication LAN and the wired communication LAN, a communication cycle can be defined and data transmission can be performed. The time-guaranteed polling select method or token passing is used.

The master station 51, when transmitting / receiving data to / from the slave station 52, preliminarily joins the network to the slave station 52.
After confirming, the data such as control information is transmitted and received.

[0009]

However, in a network system having a wireless communication LAN which has been introduced and widely used in manufacturing sites, the slave station 5 received by the master station 51 is received.
As the data from No. 1 is received, only the one having the strongest radio wave intensity is received, so that it is practically impossible to detect the address duplication.

Therefore, in the network system as described above, which has been introduced into the manufacturing site and has been popularized, the network system operates while having the duplicated address.
The data transmitted from the master station 51 controls the device I
If it is the / O data, there is a problem that not only the production line does not normally operate but also a runaway of the equipment may lead to a serious accident.

Here, in the wireless communication LAN, it is substantially impossible to detect the duplication of addresses. For example, the slave station 52 of A and the slave station 52 of B are overlapped and the addresses are set. The case will be described as an example.

When the response frame to the polling frame transmitted by the master station 51 is assumed to be stronger than the response frame received from the slave station 52 of B in the response frame received from the slave station 52 of A The master station 51 recognizes that a normal response frame has been transmitted in response to the previously transmitted polling frame as a result of receiving the radio wave of the response frame transmitted by the slave station 52 of A. It is practically impossible to detect duplicate addresses.

Therefore, when the master station 51 subsequently transmits valid data to the slave station 51 of the corresponding address, the slave station 52 of A and the slave station 52 of B receive the data. .

In the wired communication LAN, the wireless communication LA
Explain that unlike the N system, the duplicate address can be easily detected.

For example, a slave station whose address is set to overlap with a polling frame from the master station sends a response frame to the master station in response to the polling frame from the master station almost at the same time. In the response frame to be transmitted, the data is overlapped and the bit information is destroyed by the response frame transmitted by each slave station.

As a result, the master station judges that there is no response to the transmitted polling frame, and even if the polling frame is retransmitted many times, only the response frame as the error frame is received and the normal response frame cannot be received. .

Therefore, in the wired network system,
It can be detected that the addresses are duplicated in the corresponding address.

Therefore, in view of the above-mentioned problems, by stopping the operation of the slave station having the duplicated address,
It is an object of the present invention to provide a network system that notifies an administrator or a worker that he has a slave station having a duplicate address.

[0019]

In order to achieve the above-mentioned object, the invention according to claim 1 is a network system including a master station and a slave station, wherein the master station has a transmission destination address set by a user. , A duplicate registration check polling frame having a unique address that each slave station cannot uniquely set is transmitted by the slave station, and when the slave station receives the duplicate registration check polling frame, the duplicate registration check polling frame When the transmission destination address and the unique address are read, and the transmission addresses are the same but the unique addresses are different, the operation is stopped assuming that the addresses of the own station are duplicated.

According to a second aspect of the present invention, in the first aspect of the present invention, a network table for storing subscription information indicating whether the master station has joined or left the network, and a network table for the network. A unique address information table that stores unique address information that becomes the unique address for the sub-stations that have joined, and based on the network table and the unique address information table, the duplicate registration inspection polling frame To be transmitted to the slave station.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the invention described above, when the master station completes the duplicate registration check polling sequence, a predetermined number is added to or subtracted from an address set by the user to make it an address outside the user-set range, and the address is transmitted. The transmission frame having the destination address is transmitted to the slave station.

[0022]

The invention according to claim 4 is the same as claims 1 to 3.
In the above invention, the master station refers to the unique address information table, sends a join confirmation polling frame having the unique address to the leaving slave station, and the slave station receives the join request. If the destination address of the confirmation polling frame is the same as that of its own station, but if the unique address is different, it recognizes that there is the same address and stops the operation.

The invention according to claim 5 is the same as claims 1 to 4.
In the invention described above, the duplicate registration check polling frame transmitted by the master station to stop the operation of the slave station in which the duplicate address is registered, and the parent station when the slave station leaves the network this time when it was previously subscribed Only the subscription confirmation polling frame transmitted by the station to the slave station is a transmission frame having a destination address set by the user and a unique address which cannot be set by the user and which each slave station has uniquely,
In other transmission frames, the transmission frame does not have the unique address.

In the present invention, when the slave station receives the multiple registration check polling frame, it reads out the destination address and the unique address in the duplicate registration check polling frame, and the transmission addresses are the same, but the unique addresses are different. Will stop the operation because the address of its own station is duplicated.

Further, when the slave station receives a transmission frame having no unique address after the duplicate registration check polling sequence, even if the transmission address is the same as that of the self station, the polling confirmation information storage means is stored. If the polling confirmation information is not stored in, the operation is stopped assuming that the address of the own station is duplicated.

Further, when the destination address of the received join confirmation polling frame is the same as that of the own station but the unique address is different, the slave station recognizes that there is the same address and stops operating. To do.

[0028]

DETAILED DESCRIPTION OF THE INVENTION A network system according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of a network system according to an embodiment of the present invention.

The network system of this embodiment is
As shown in FIG. 1, a programmable controller 10 as a host station, a # 1 master station having a use band of a channel CH1, and a # 2 master station 11 having a use band of a channel CH2 are remote I / O networks 20. Is connected to the wired communication LAN, and the master stations 11 of # 1 and # 2 are connected to the plurality of slave stations 12 by the wireless communication LAN, and the polling is performed as the communication method of the wired communication LAN and the wireless communication LAN. -A selecting method is adopted.

In the network system of this embodiment, one communication cycle from polling the slave station 12 managed by the master station 11 of # 1 and # 2 to polling again is shown in FIG. As described above, the cyclic communication phase in which the slave station 12 is regularly polled,
It has a peripheral phase, for example, a notification phase that causes a monitor device (not shown) to display the radio wave reception status at each slave station 12.

In the cyclic phase, the parent station 11 transmits to the child station 12 a join confirmation polling frame, an idle polling frame, an initial data frame and a cyclic data frame which is I / O data.

Here, the join confirmation polling frame is a frame for requesting a response to the slave station 12 as to whether or not to join the wireless communication LAN, and the initial data frame is for the slave station 12 which has requested to join. On the other hand, it is a frame having setting data such as communication parameters necessary for network operation.

Here, the transmission frame used in the network system of this embodiment will be described.

As shown in FIG. 3A, the transmission frames used in the wireless communication LAN constituting the network system of this embodiment include a first transmission frame 70 having no unique address area, and a transmission frame shown in FIG. As shown in b), it has a second transmission frame 80 having a unique address area.

The first transmission frame 70 having no unique address area is used for a subscription confirmation polling frame, a response frame for this subscription confirmation polling frame, and a response frame for initial data.

The first transmission frame 70 has a synchronization flag (SYN) area 70a having a 1-byte length having a synchronization flag for designating a head portion of the frame, and a transmission destination having a 1-byte length having an address of the transmission destination. An address (DA) area 70b and a source address 1
Source address (SA) area 70c consisting of byte length
A control code (CF) area 70e having a 2-byte length having information for identifying the type of frame, and a data area 70f having a 4-byte length having I / O data, call code (CallSign) data, and the like. 1 having a flag check sequence area 70g having a 2-byte length and a synchronization flag for designating an end point of a frame
It is composed of a synchronization flag (SYN) area 70h having a byte length.

The second transmission frame 80 having a unique address area is used for a subscription confirmation polling frame transmitted for confirming the departure when joining last time and leaving this time, and a duplicate registration check polling frame.

In the frame 80, a sync flag (SYN) area 80a having a 1-byte length having a sync flag for designating a head portion of the frame and a destination address having a 1-byte length having a destination address ( D
A) area 80b, and a source address (SA) area 80c having a 1-byte length and having a source address,
A unique address area 80d having a 5-byte length having a calling code (CallSign) of the slave station 12, a control code (CF) area 80e having a 2-byte length having information for identifying a frame type, and I / O data, A data area 80f having a 4-byte length having call code (CallSign) data and the like, a flag check sequence area 80g having a 2-byte length, and a synchronization flag having a 1-byte length having a synchronization flag designating an end point of the frame ( SYN) area 80h.

The second frame 80 shown in FIG.
Does not have a unique address (SN) area 80d 12
Compared with the first frame of byte length, 1.4 (17/1
2) It has double the length.

The host PLC 10 controls devices to be controlled such as sensors and motors.

The # 1 master station 11 employs a spread spectrum system as a communication system executed with the slave station 12,
“W as an ID that specifies the channel group to use
GID ”has“ 1 ”, and the master station 11 of # 2
Has "WGID" of "2".

Further, the master stations 11 of # 1 and # 2 respectively
It has a network table to be described later, and based on this network table, a subscription confirmation polling frame (described later), a duplicate registration inspection polling frame (described later), etc. are transmitted to the slave station 12.

Further, the master stations 11 of # 1 and # 2 each have a unique data storage table (described later), and a call code (CallSign) (unique data is stored in this unique data storage table. A certain address is used as a unique address, and a duplicate registration check polling frame and an initial data frame are transmitted to the slave station 12.

Here, the reason why the call code is used as the unique address is that the call code is unique data that identifies the own station to be transmitted when performing wireless communication (based on the law) in Japan. .

Next, the network table and the unique data storage table will be described.

As shown in FIG. 4, the network table 111 has a WNID area 111a having a WNID as an ID for designating the slave station 12 and whether the slave station 12 designated by the WNID is joined to the wireless communication LAN system. Join flag area 111 having a flag indicating whether or not
b and.

WNIDs are serial numbers such as 1, 2, 3, ..., N, and when the joining flag is "1", the corresponding slave station 12 joins the wireless communication LAN. "0" indicates that the corresponding slave station 12 has left the wireless communication LAN.

As shown in FIG. 5, the unique data storage table 112 has a WN as an ID for designating the slave station 12.
A WNID area 112a having an ID and a call code area 112b having a call code included in a response frame transmitted from the mobile station 12 after performing a polling confirmation on the mobile station 12 and joining the wireless communication LAN. It consists of and.

Incidentally, the WNID area 112 denoted by A is shown.
The call code of a is "CallSign-1".

Like the master station 11, the slave station 12 has a "WGID" as an ID for designating a channel group to be used, and the slave station 12 using the same channel.
“WNID” as an ID for specifying

Incidentally, the slave station 12 shown by A in the figure is
It has “2” as “WGID” and “1” as “WGID”, and the slave station 12 shown in B in the figure is
It has “2” as “WGID” and “2” as “WGID”.

Further, when the slave station 12 receives the join confirmation polling frame from the master station 11, when it joins the wireless communication LAN, it sends a response frame to the master station 11.

When the slave station 12 receives the duplicate registration check polling frame from the master station 11, the slave station 12 transmits a response frame for the polling registration polling frame to the master station 11, and the master station 11 also receives the response frame.
The master station 11 receives a response signal indicating that the initial data frame has been received from
It is designed to be sent to.

Further, when the slave station 12 receives the subscription confirmation polling frame or the duplicate registration check polling frame from the master station 11, the slave station 12 sets "1" in the polling confirmation area formed in the work area of the RAM (not shown).
(Polling confirmation flag) should be set.

When the response frame to the subscription confirmation polling frame or the duplicate registration inspection polling frame is not transmitted to the master station 11, the flag of the polling confirmation area is "0".

Next, the operation of this network system will be described with reference to the sequence diagram of FIG.

After the power is turned on or at a predetermined time interval, the master station 11 issues a join confirmation polling frame for inquiring whether or not the slave station 12 joins the wireless communication LAN, with a child whose WNID is "1". WNID from station 12 is "n"
Sequentially transmitted to the slave stations 12 (in FIG. 6 ,,,
, E)).

When the slave station 12 receives the join confirmation polling frame from the master station 11, it sets "1" in the polling confirmation area, and when joining the wireless communication LAN,
In the data area 70f of the frame, the calling code (CallS
6) is transmitted to the master station 11 (see f in FIG. 6). On the other hand, when the wireless communication LAN is not joined, nothing is transmitted to the master station 11.

When the master station 11 receives the response frame for the subscription confirmation polling frame from the slave station 12, the slave station 12 stores the corresponding frame in the unique data storage table.
The call code possessed by is stored (see g in FIG. 6).

Here, the master station 11 cannot transmit the join confirmation polling frame transmitted to the slave station 12 due to fading or the like, or even if the join confirmation polling frame can be transmitted from the slave station 12. When you can not receive the response frame of
Even when the slave station 12 has a request to join the wireless communication LAN, the slave station 12 is disconnected.

Then, the corresponding slave station 1 that should operate normally
The control device connected to No. 2 will not operate and will cause a serious failure.

Therefore, a. When the master station 11 transmits the subscription confirmation polling frame at the time of power-on to the slave station 12, the master station 11 transmits the subscription confirmation polling frame having no unique address a predetermined number of times (see FIG. 6),
Try to prevent separation.

As a result, when the master station 11 does not receive the response frame to the subscription confirmation polling frame from the slave station 12 (see FIG. 6), the location of the corresponding slave station 12 in the network table 111 is set to "". It is set to 0 ", and the slave station 12 is separated from the wireless communication LAN (see FIG. 6).

On the other hand, when the master station 11 receives the response frame for the subscription confirmation polling frame from the slave station 12, the master station 11 registers the calling code of the slave station 12 at the corresponding position.

B. Even if the master station 11 transmits the subscription confirmation polling frame (see FIG. 6) and there is no response frame for it (see FIG. 6),
Further, when the destination slave station 12 has joined the wireless communication LAN last time, it refers to the call table 112 a predetermined number of times and transmits a join confirmation polling frame having a unique address consisting of a call code (FIG. 6). (See a and b).

As a result, when the master station 11 does not receive a response frame to the subscription confirmation polling frame from the slave station 12 (see c in FIG. 6), the location of the slave station 12 in the network table 111 is changed. Change from “1” to “0” and set this slave station 12 to wireless communication L
It is detached from the AN (see d in FIG. 6).

On the other hand, when the master station 11 receives the response frame for the subscription confirmation polling frame from the slave station 12, the master station 11 updates and registers the calling code of the slave station 12 at the corresponding position in the unique data storage table.

The master station 11 is a slave station 12 whose WNID is "n".
When the above-described processing for the subscription confirmation polling for the is completed, the unique data storage table 112 is referred to and the duplicate registration check polling frame having the unique address including the calling code is transmitted from the slave station 12 having the WNID of “1” to the WNID. The data is sequentially transmitted to the “n” slave stations 12 (see h, k, and p in FIG. 6).

Upon receiving the duplicate registration check polling frame, the slave station 12 sends a response frame corresponding to the polling frame to the master station 1.
1 (see i and q in FIG. 6).

When the master station 11 receives the response frame for the duplicate registration check polling frame from the slave station 12, the slave station 12 that has transmitted this response frame joins the wireless communication LAN in order to join the corresponding part of the network table 111. The joining flag is set to "1" (see j and r in FIG. 6).

On the other hand, if the master station 11 outputs the duplicate registration inspection polling frame to the slave station 12 a predetermined number of times (see l in FIG. 6), it must receive a response frame corresponding thereto (see FIG. 6). (See m in the figure), the slave station 12 that has transmitted the duplicate registration inspection polling frame recognizes that it does not join the wireless communication LAN, and the unique data storage table 1
The call code of the corresponding place of 12 is deleted (see n in FIG. 6), and the joining flag of the corresponding place of the network table 111 is set to “0” (see o in FIG. 6).

The master station 11 is a slave station 12 whose WNID is "n".
When the above-mentioned processing for duplicate registration check polling for the above is completed, the network table 111 is referred to and the initial data frame is sequentially transmitted to the slave station 12 having the WNID “n” sequentially from the slave station 12 having the WNID “1”. Is transmitted (see s and u in FIG. 6).

Upon receiving the initial data frame, the master station 11 reads out the setting data such as communication parameters necessary for the network operation described in the frame, sets the read communication parameters and the like, and informs that the setting is completed. The response frame is output to the master station 12 (see t and v in FIG. 6).

The master station 11 is the slave station 12 whose WNID is "n".
When the above-described processing for the initial data for the above is completed, the joining confirmation processing in this wireless communication LAN is completed.

Subsequently, the slave station 12 with the dual address set
The process of stopping the operation of will be described separately for the following cases.

(1) When the master station 11 is activated, the slave station 11
7 is a sequence diagram for stopping the operation of the slave station having the overlapping address registered when the master station is activated.

The master station 11 turns on the power source to start the activation, and transmits a join confirmation polling frame to the slave station 12.

The slave station 12 of # 1 and the slave station 12 of # 2 are
When the subscription confirmation polling is received from the master station 11 (see in FIG. 7), “1” is set in the polling confirmation area and a response frame is transmitted to the master station 11 (FIG. 7).
See inside).

In the master station 11, since the received radio wave intensity of the # 1 slave station 12 is stronger than the received radio wave intensity of the # 2 slave station 12,
Of the slave station 12 of # 1 is preferentially received, and then the slave station 12 of # 1 is added to the unique address area 80d.
The duplicate registration check polling frame having the calling code of is transmitted (see, in FIG. 7).

Upon receiving the duplicate registration check poll from the master station 11, the slave station 12 of # 1 refers to the destination address area 80c and the unique address area 80d in the duplicate registration check polling frame, and sends it to itself. The frame is recognized as the received frame and the response frame is output (see FIG. 7).

On the other hand, when the slave station 12 of # 2 receives the duplicate registration check poll from the master station 11, it refers to the destination address area 80c and the unique address area 80d in the duplicate registration check poll frame, The destination addresses in the address area 80c are the same, but the unique address in the unique address area 80d does not have the calling code of its own station.
It recognizes that it has a duplicate address and stops its operation (see FIG. 7).

In this way, from the wireless communication LAN to the slave station 12
When the operation of the above is stopped, the worker or the manager can indirectly recognize that it has duplicate registration in the network system.

(2) When the user joined the wireless network last time and leaves the wireless network this time, the slave station 11
8 is a sequence diagram of stopping the operation of the slave station having the duplicate address registered when the user joined the wireless network last time and left the wireless network this time.

As described above, when the slave station 12 leaves the wireless network, it is necessary to really leave and therefore the response frame for the subscription confirmation polling is not transmitted, or the slave station 12 transmits the subscription confirmation polling frame. However, due to fading, etc., the master station 1
In order to confirm whether or not 1 has been reached, processing for transmitting a subscription confirmation polling frame a predetermined number of times is performed (see FIG. 6).

At this time, for example, when the slave station 12 having the same address (destination address) enters from the outside of the communication area into the communication area, or when the slave station 12 having the same address turns on the power, This is to prevent the slave station 12 from transmitting a response frame to the master station 11 when the slave station 12 receives the subscription confirmation polling frame, and to stop the operation of the slave station 12 having the duplicate address.

The master station 11 refers to the unique data storage table 112 (see FIG. 8), and leaves the slave station 1
2, a subscription confirmation polling frame having a unique address composed of a calling code is transmitted (see FIG. 8).

Then, as described above, the # 2 slave station 12 having the same address as the # 1 slave station 12 entering the communication area from outside the communication area is transmitted by the master station 11. It receives the subscription confirmation polling frame and sets "1" in the polling confirmation area.

Then, the slave station 12 of # 2 has the same destination address as the destination station of the received frame,
If the unique addresses are different, it recognizes that the wireless network system has the same address and stops the operation (see FIG. 8).

(3) In the case where a command frame such as initial data is transmitted to the wireless slave station 12 having an overlapping address within the communication area of the wireless network, that is, the wireless slave station having the overlapping address described so far. The process for stopping the operation of is performed in the subscription confirmation polling sequence and the duplicate registration check polling sequence, but the subscription confirmation polling sequence and the duplicate registration check polling sequence are completed, and the subscription confirmation polling sequence is transmitted again. Up to, for example, a process of stopping the operation of the wireless slave station having the duplicated address when the initial data frame is transmitted will be described.

FIG. 9 is a sequence diagram showing the operation of stopping the operation of the duplicated wireless slave stations when the command frame such as the initial data is transmitted.

The wireless master station 11 sets the "WNID" set by the user to, for example, 80H (H) until the subscription confirmation polling sequence and the duplicate registration check polling sequence are completed and the subscription confirmation polling sequence is transmitted again.
Is the hexadecimal display) "WNID + 80
The initial data frame or the like having the transmission destination address transited to H ″ (address that cannot be set by the user with the address setting switch) is transmitted (see FIG. 9).

Then, the wireless slave station # 1 and the wireless slave station # 2 both receive this initial data frame.

Since the polling confirmation flag in the polling confirmation area of the wireless slave station 12 of # 2 is "0", it enters the communication area from outside the communication area after the join confirmation polling sequence and the duplicate registration check polling sequence. Or, the power is turned on, and the station recognizes that it has not joined the wireless network and stops operating.

Since the wireless slave station 12 of # 1 has gone through the join confirmation polling sequence and the duplicate registration check polling sequence, the polling progress flag is "1", so that the self station joins the wireless network. I recognize that

In the network system of this embodiment, when the slave station 12 receives the multiple registration check polling frame, it reads the destination address and the unique address in the duplicate registration check polling frame, and the transmission addresses are the same. If the unique addresses are different, the address of the local station is duplicated and the operation is stopped.

When the slave station 12 receives a transmission frame having no unique address after the duplicate registration check polling sequence, even if the transmission address is the same as that of the own station, the slave station 12 stores and stores the polling confirmation information. If the polling confirmation information is not stored in the means, the operation is stopped assuming that the address of the own station is duplicated.

Further, when the transmission destination address of the received join confirmation polling frame is the same as that of the own station but the unique address is different, the slave station recognizes that there is the same address and stops operating. To do.

As described above, the slave station 11 having the duplicated address can inform the manager or the worker that the slave station 11 has the duplicated address by stopping its operation.

In the network system of this embodiment, among the frames to be transmitted, the duplicate registration check polling frame transmitted by the master station 11 to stop the operation of the slave station 12 in which the duplicate address is registered, and the previous subscription. Then, when the slave station 12 leaves the wireless communication LAN this time, only the subscription confirmation polling frame transmitted from the master station 11 to the slave station includes the transmission destination address set by the user and the slave station 12 which cannot be set by the user. Is the second transmission frame 80 having its own unique address, and the other transmission frames are the first transmission frame 70 having no unique address, so that wireless communication is performed without reducing the transmission efficiency. be able to.

The network system of this embodiment is
Although the calling code is used as the unique address, other than that, the serial numbers of the products owned by the master station 11 and the slave station 12 and the MAC address of the Ethernet may be used as the unique address. You may use the generated random number for a unique address.

Even when a random number is used, as shown in FIG. 10, the same processing as the call code used in the network of this embodiment is performed, and therefore the detailed description of the processing is omitted.

[0103]

As described above, according to the present invention, when the slave station receives the multiple registration check polling frame transmitted by the master station, the destination address and the unique address in the duplicate registration check polling frame are read and the transmission address is If the addresses are the same but the unique addresses are different, it is possible to stop the operation assuming that the addresses of the own station are duplicated.

Further, even when the slave station receives a transmission frame having no unique address after the duplicate registration check polling sequence, even if the transmission address is the same as that of the own station, the polling confirmation information storage means is stored. If the polling confirmation information is not stored in, the operation is stopped assuming that the address of the own station is duplicated.

Further, the slave station recognizes that there is the same address when the transmission destination address of the received join confirmation polling frame is the same address as that of its own station, but stops the operation. To do.

As a result, the manager or the worker can be informed that he / she has the slave station having the duplicate address, and serious troubles can be prevented in the system at the manufacturing site.

Among the frames to be transmitted, the duplicate registration check polling frame transmitted by the master station to stop the operation of the slave station in which the duplicate address is registered, and the child frame from the wireless communication LAN that was previously subscribed and is currently transmitted. When a station leaves, only a subscription confirmation polling frame transmitted by the parent station to the child station has a destination address set by the user and a unique address that cannot be set by the user and is unique to each child station. In other transmission frames, since the transmission frame does not have a unique address, wireless communication can be performed without reducing the transmission efficiency.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a network system according to the present invention.

FIG. 2 is an explanatory diagram of processing contents of one communication cycle included in the network system of this embodiment.

FIG. 3 is a block diagram showing the configuration of a transmission frame used in the network system of this embodiment.

FIG. 4 is a block diagram showing the configuration of an address table.

FIG. 5 is a block diagram showing the configuration of a unique data storage table.

FIG. 6 is a sequence diagram showing processing of the network system of this embodiment.

FIG. 7 is a sequence diagram when a slave station finds a double registration in the processing of the network system of this embodiment.

FIG. 8 is a sequence diagram when a slave station finds double registration in the processing of the network system of this embodiment.

FIG. 9 is a sequence diagram when a slave station finds double registration in the processing of the network system of this embodiment.

FIG. 10 is a sequence diagram when a random number is used as unique data.

FIG. 11 is a schematic configuration diagram of an embodiment of a conventional network system.

[Explanation of symbols]

10 programmable controller 11 parent station 12 slave stations 20 Remote I / O network 111 Address table 112 Unique data storage table 70 First transmission frame 80 Second transmission frame

Continuation of the front page (56) Reference JP-A 63-299416 (JP, A) JP-A 1-218223 (JP, A) JP-A 62-165445 (JP, A) JP-A 10-93464 (JP , A) JP-A-5-276096 (JP, A) JP-A-4-249454 (JP, A) JP-A-11-136724 (JP, A) JP-A-3-141732 (JP, A) JP-A-3-141732 (JP, A) 6-245276 (JP, A) JP-A-3-62636 (JP, A) JP-A-6-244788 (JP, A) JP-A-62-221231 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B ^7/ 24-7/26 H04Q ⁷ /00-7/38

Claims (5)

(57) [Claims] 1. A network system including a master station and slave stations, wherein the master station has a duplicate registration check having a destination address set by a user and a unique address that cannot be set by the user and is unique to each slave station. When transmitting the polling frame, the slave station, when receiving the duplicate registration check polling frame, reads the destination address and the unique address in the duplicate registration check polling frame, and the transmission address is the same, but the unique address If they are different, the network system is characterized by stopping the operation because the address of its own station is duplicated. 2. The network of the master station, which stores subscription information indicating whether to join or leave the network, and to the slave stations subscribed to the network,
A unique address information table that stores unique address information that serves as the unique address, and forms the duplicate registration inspection polling frame based on the network table and the unique address information table and sends it to the slave station. The network system according to claim 1, wherein: 3. When the duplicate registration inspection polling sequence ends, the master station performs an operation such as adding or subtracting a predetermined number to an address set by the user to make it an address outside the user setting range, and transmits the address. The network system according to claim 1 or 2, wherein a transmission frame having a destination address is transmitted to the slave station. 4. The master station leaves by referring to the unique address information table.
Subscribe to the slave station with the unique address
A confirmation polling frame is transmitted, and the slave station sends a destination address of the received subscription confirmation polling frame.
Address is the same as your own station, but unique address
If they are different, it is recognized that they have the same address.
4. The operation is stopped by stopping the operation.
Network system. 5. The operation of a slave station in which a duplicate address is registered
Duplicate registration inspection policy sent by the parent station to stop
Ning frame and the last time you subscribed to this network
When the slave station leaves the remote station, the master station sends a confirmation message to the slave station.
Only the polling frame is the destination set by the user.
Each slave station has its own address and cannot be set by the user
It is a transmission frame having a unique address, and in the other transmission frames, the unique address is
2. A transmission frame that does not have a frame.
The network system according to any one of claims 1 to 4.