JP2002026914A - Network unit, and recording medium for recording its program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce trouble at network address setting in a local area network where a manufacturer of a network device is limited such as a control system having control display devices and a host computer. SOLUTION: Upon the receipt of an own generation instruction of an IP address from a control host computer 6, an address setting section 46 of each programmable display device 4 stores a serial number of a MAC address of its own device to a predetermined 1st area in an IP address storage section 42b and also stores a part of a MAC address vender ID in a remaining 2nd area. When the generated IP address is coincident with an IP address of the control host computer 6, the section 46 changes the value of the 2nd area. Thus, each programmable display device 4 can set a unique IP address by itself without the need for communication with other programmable display devices 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitably used in a local area network in which manufacturers of network devices are limited, such as a control system having a plurality of display devices for control and a host computer. The present invention relates to a network device capable of reducing the time and labor required for setting a program, and a recording medium on which the program is recorded.

[0002]

2. Description of the Related Art As shown in FIG. 9, a system for interconnecting a plurality of network devices 101 via a local area network (LAN) 102 such as Ethernet (registered trademark) has been widely used. It is used. In these systems, TCP / IP (Transm
When data is transmitted using ission Control Protocol / Internet Protocol), a data sequence is transmitted after being divided into packets. Also, each packet contains
I indicating the source and destination network devices 101
P address is added, and each network device 10
Reference numeral 1 identifies whether or not the packet is directed to the own device based on the IP address.

[0003]

However, in the above-mentioned conventional configuration, it is necessary to set a unique value in the LAN 102 as the IP address of each network device 101, regardless of the scale of the system, which is troublesome. Cause problems.

[0004] Specifically, the IP address is a sequence of four 32-bit numbers such as "192.168.0.10". For example, a user who is not accustomed to a network, such as a user who constructs a network for the first time. Is unfamiliar and difficult to set / remember. Further, these IP addresses need to be set not only in each network device 101 but also in each of the LANs 102 so as to be set to unique values, so that the burden on the user is further increased.

In particular, in a conventional control system, the control display device connected to the PLC is often connected by a serial cable, and the user of the control display device is often unfamiliar with the network. In the control system, many control display devices are used. Therefore, especially in a control system, a burden when a user sets an IP address tends to be large.

[0006] The present invention has been made in view of the above problems, and has as its object, for example, a control system having a plurality of control display devices and a host computer.
It is an object of the present invention to provide a network device which is suitably used in a local area network where a manufacturer of the network device is limited, and which can reduce the trouble when setting a network address.

[0007]

In order to solve the above-mentioned problems, a network device according to the present invention comprises a vendor identifier indicating a manufacturer and an identification number for distinguishing devices having the same vendor identifier. Hardware address storage means for storing a combination of hardware addresses, the bit width being wider than the identification number, and the source and destination of the data based on the network address assigned to the data to be transmitted. Local
A network device connectable to an area network is characterized by the following measures.

That is, when a self-generation instruction of a network address is received via the local area network, the self-generated network address of the self-device is referred to by referring to the hardware address storage means. It has. Further, the network address generating means includes a first value having a value corresponding to the identification number of the own device and different from a value corresponding to the other identification number, a vendor identifier of the own device, and Based on a combination of a predetermined value and a second value of a predetermined value that is different from a value corresponding to another vendor identifier of a predetermined vendor identifier group, if the combination is different, the values are different from each other. A network address setting means for setting a network address, and whether the network address set by the network address setting means may have the same value as the network address indicating the transmission source of the self-generation instruction. And a determining means for determining whether the same value is likely to be obtained. Any that the second value adjusting means for instructing to the network address setting means is provided to also change the second value to the value determined differently in advance.

In the above configuration, when the host computer receives a self-generation instruction of a network address from the local area network, for example, by simultaneously broadcasting to the local area network, the network address generation means of the network device operates. The network address is self-generated by referring to the hardware address storage means of the own device.

[0010] Specifically, the network address generation means extracts the identification number from the hardware address of the own device, for example, to obtain a value corresponding to the identification number of the own device, and further, to the other identification number. A first value different from the corresponding value is derived. Further, the network address generating means includes: a network device having the same vendor identifier;
For example, when it is assumed that a local area network is formed with a device such as a host computer that transmits a self-generated instruction, for example, a predetermined fixed value or a part of a vendor identifier is extracted. A second value is derived as a value or the like. On the other hand, a network device having a vendor identifier included in a predetermined vendor identifier group,
When it is assumed that a local area network is formed with the transmission source device of the self-generation instruction, for example,
The second value is derived by referring to a correspondence table between the vendor identifier of the group of vendor identifiers and the second value, or by referring to a value corresponding to the vendor identifier of the own device. In any case, the second value is set to a value different from a value corresponding to another vendor identifier in a predetermined vendor identifier group. Further, the network address setting means may use a derivation method such that, when the combination of the first value and the second value is different from each other, for example, the first value and the second value may be different from each other, for example. Derive the network address of

[0011] The second value adjusting means may be provided when there is a possibility that both network addresses may be the same, for example, when the network address of the own device is the same as the network address of the transmission source of the self-generation instruction. Instruct the network address setting means to change the second value to a predetermined value different from any of the values corresponding to the vendor identifiers of the vendor identifier group. This allows
The network address generated by the network device is always different from the network address of the transmission source of the self-generation instruction.

Here, for example, in a local area network for a specific use such as a control system, a network system is often composed of one or more network devices of a specific manufacturer and a host computer. Even when the manufacturers of the network devices do not match, these manufacturers often belong to a relatively restricted group.

[0013] In this case, between network devices having different vendor identifiers, the second values derived by the respective network address setting means are different from each other.
Therefore, among these network devices, the network devices that are not adjusted by the second value adjusting unit are:
Network addresses are set to different values. Further, depending on the derived second value, a network address set by the network address setting means,
Although the network address of the transmission source of the self-generation instruction may be duplicated, the second value changed by the second value adjusting unit is different from any of the second values when no adjustment is performed. Therefore, the network address of the network device adjusted by the second value adjusting unit has a different value from the network address of the network device not adjusted. On the other hand, since network devices having the same vendor identifier have different identification numbers, the first values derived by the respective network address setting units are different from each other regardless of whether or not adjustment is performed by the second value adjustment unit. I do. As a result, each network device is
With other network devices in the area network,
A unique network address different from the source of the self-generation instruction can be set.

In the above configuration, the local equipment including the network device having the specific vendor identifier or the vendor identifier of the specific vendor identifier group and the transmission source of the self-generation instruction are provided.
In the area network, although the user of the local area network does not specifically set,
After receiving a self-generation instruction from the host computer, each network device uses a unique value in the local area network as its own network address without communicating with other network devices or the host computer. Can be set. As a result, the time and effort required to manage the local area network can be significantly reduced.

Further, the network equipment according to the second aspect of the present invention is characterized in that, in the configuration of the first aspect, the network equipment is a control display device for displaying a state of a control target. .

Here, manufacturers of the display devices for control are limited, and many control display devices are connected to a host computer via a local area network in a control system in many cases. Therefore, by providing the control display device with each means of the network device,
Significant savings in managing the control system local area network.

The network device may be realized only by hardware, or may be realized by executing software on a computer. In particular,
The recording medium according to claim 3, further comprising hardware address storage means storing a hardware address composed of a combination of a vendor identifier indicating a manufacturer and an identification number for distinguishing devices having the same vendor identifier, A network address setting program for a computer connectable to a local area network that specifies a source and a destination of data based on a network address assigned to data to be transmitted having a bit width wider than the identification number. In order to solve the above-mentioned problems, the recording medium according to the present invention is characterized in that a program for operating the computer is recorded.

When a program is read from the recording medium having the above configuration and executed by the computer, the computer operates as the network device according to the first aspect. As a result, similar to the first aspect, the time and effort for managing the local area network including the network device having the specific vendor identifier or the vendor identifier of the specific vendor identifier group and the transmission source of the self-generation instruction are reduced. Can be significantly reduced.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention.
The following is a description based on FIG. That is, as shown in FIG. 2, the control system 1 according to the present embodiment is a system for controlling the state of the target system 2 including devices 2a... Such as motors, valves or sensors. Logic Controller (PL)
C) and, in most cases, are arranged in the vicinity of the target system 2 and communicate with the PLC 3 to display the status of the device 2a, display the communication result and the operator's A programmable display (network device; control display) 4 for transmitting a control instruction to the device 2a to the PLC 3 in response to the instruction, and a local area network (LAN) connecting the programmable displays 4 to each other 5 and
A control host computer 6 is connected to the LAN 5 and controls the entire control system 1 from a position farther from the target system 2 than the programmable display 4 in many cases.

Here, the PLC has a history of evolving from a sequencer, and many PLCs have their own dedicated protocols, for example, for each type of PLC, such as for each manufacturing company or each product type. However, in the control system 1 according to the present embodiment, the programmable displays 4 are directly connected by the LAN 5. Thus, unlike the conventional control system in which the PLC is interposed in the communication processing in the control system, the control system 1 has a configuration essential to the control system 1, and has more computational capacity and storage capacity than the PLC 3 for screen display. The programmable display 4 having a large margin can process most of the communication. Further, each programmable display 4 converts between a dedicated protocol specific to the model of the PLC 3 connected to itself and a common protocol predetermined for communication on the network 5, and converts the other programmable displays 4. And relays communication between the control host computer 6 and the PLC 3. Thus, the programmable display 4 and the control host computer 6 instruct the PLC 3 connected to another programmable display 4 to control,
Although the status of the device 2a controlled by the LC 3 can be acquired, communication can be performed by a predetermined common protocol without depending on the model of the PLC 3 connected to the other programmable displays 4. As a result, it becomes easier to mix different types of PLCs 3 in the control system 1 than in the control system in which the PLCs are directly connected.

More specifically, the programmable display 4 according to the present embodiment is a display capable of controlling input and screen display based on screen data determined by combining processing instruction words (tags). , As shown in FIG.
Interface unit (IF) connected to C3 or LAN5
As a unit), a dedicated protocol IF unit 41 / common protocol IF unit 42, a protocol conversion unit 43 for relaying communication between the two IF units 41/42, and a control program and control data such as the screen data are stored. And a display / control processing unit 45 that performs a display / control operation based on screen data stored in the storage unit 44 in accordance with an operator operation or a communication result input from a touch panel or the like. ing.

The storage section 44 is a non-volatile recording medium such as a FEEPROM (Flash Electrically
A non-volatile semiconductor memory such as rasable and programmable ROM) is provided. The non-volatile semiconductor memory generally takes longer to write than to read, but unlike a disk-shaped recording medium such as a hard disk or a tape-shaped recording medium, does not have a movable part. Therefore,
Even in a poor environment near the target system 2, the control program such as screen data and the control data can be maintained without malfunction. When the common protocol IF unit 42 receives an instruction to write a control program from the control host computer 6, the storage unit 44 can write the control program or control data in the nonvolatile semiconductor memory.

Further, the LAN 5 according to the present embodiment is an Ethernet (registered trademark), and the common protocol I
The F section 42 converts the data string in a format that can be understood by each programmable display 4 and the control host computer 6 into
CP / IP (Transmission Control Protocol / Intern
et Protocol). The common protocol IF unit 42 includes a MAC address storage unit (hardware address storage unit) 42a that stores a MAC (medium access control) address given to the device at the time of manufacture as a hardware address, and a network address. And an IP address storage unit 42b for storing an IP address given to the own device prior to data communication using the TCP / IP protocol. MA above
As shown in FIG. 3, the C address is a 48-bit value determined at the time of manufacture so as to be a unique value (unique value) for a device transmitting data via Ethernet.
It consists of a vendor ID (24 bits) indicating the manufacturer and a serial number (24 bits) unique to the manufacturer. In the control system 1 according to the present embodiment, the programmable displays 4 manufactured by the same manufacturer are used, and the vendor IDs stored in the MAC address storage unit 42a of each programmable display 4 are the same as each other. Value. Also, each MAC address storage unit 42a
Stores different serial numbers.

On the other hand, the IP address is a value having a 32-bit width, and is uniquely given to each device that the network layer communicates by the IP protocol regardless of the communication path used as the data link layer or the physical layer. . Note that the IP address is used when the LAN 5 does not communicate with another network.
If it is unique within the LAN 5, it may be the same value as an IP address in another network.

Further, when the common protocol IF section 42 receives an instruction to set an IP address from the control host computer 6, the programmable display 4 according to the present embodiment refers to the MAC address storage section 42a, An address setting unit 4 that automatically generates an IP address of its own device and stores the IP address in the IP address storage unit 42b.
6 are provided. Thereby, each programmable display 4 can set the IP address of its own device without the user of the control system 1 setting in particular. Note that the address setting unit 46 corresponds to a network address generation unit, a network address setting unit, a determination unit, and a second value adjustment unit described in the claims.

More specifically, the address setting section 46
Basically, the lower 32 bits of the MAC address storage unit 42a of the own device are set as the IP address of the own device. Here, as shown in FIG. 3, the lower 24 bits of the MAC address are a serial number, and the upper 24 bits are a vendor ID. Therefore, the lower 24 bits (A1; first value) of the IP address match the serial number, and the upper 8 bits (A2; second value) of the IP address.
Value) matches the lower 8 bits of the vendor ID.

Further, the address setting section 46 generates the IP address of the own device to be set when the IP address of the device coincides with the IP address of the control host computer 6 transmitted together with the setting instruction from the control host computer 6. After changing the value of the area A2 different from the area A1 corresponding to the serial number, the IP address is stored in the IP address storage unit 42b. If the IP address does not match the IP address of the control host computer 6, the area A
2 is stored in the IP address storage unit 42b without being changed.

As a result, of the IP addresses stored in the IP address storage section 42b, the value of the area A1 is different from the IP address of each programmable display 4.
The value of the area A2 of the IP address is different from the IP address of the control host computer 6.
As a result, the IP address composed of both areas A1 and A2 has a different value from any of the other programmable displays 4 and the control host computer 6. Therefore, each programmable display 4 can set a unique IP address within the LAN 5 at a high speed without communicating with another programmable display 4 or with a server device that centrally manages the IP addresses.

On the other hand, as shown in FIG. 1, the control host computer 6 includes a display / control processing unit 61 for monitoring and controlling the entire control system 1 and a common protocol IF unit 62 connected to the LAN 5. A server unit 63 that communicates with each programmable display 4 via the protocol IF unit 62 and the LAN 5 to respond to a request from the display / control processing unit 61 and the like, and a control program for each programmable display 4 such as screen data. And a system management unit 64 for managing control data.

Here, the control program and the control data of the programmable display 4 are generally used in many programs such as hardware control processing, processing for displaying characters and graphics, and processing for receiving input from a touch panel. A system program that performs commonly used processing;
A protocol program for communicating with a predetermined communication protocol is included. Further, since the programmable display 4 according to the present embodiment is a display capable of controlling input and screen display based on screen data, the control program further includes a display / control operation of the programmable display 4. The specified screen data and, for example, an extension program such as an application program that calls the system program based on the screen data and causes each hardware of the programmable display 4 to perform the display / control operation indicated by the screen data. include.

Of the above-described control program and control data, the screen data includes a display tag indicating the correspondence between the address of the device corresponding to the display on the screen and the area on the screen, and the display tag indicating the correspondence between the area on the screen and the display tag. It is composed of an input tag indicating the correspondence between the address of the device corresponding to the input and the area on the screen, etc., and can be created more easily than the case where a program for calling and displaying / controlling the above system program is created.

More specifically, the system management unit 64
An image processing unit 71 for creating / correcting screen data and a storage unit 72 for storing a control program and control data such as the created screen data are provided. The drawing processing unit 71 displays, for example, a palette of tags, selects a tag in the palette, and prompts the user to arrange a desired tag on the screen. Further, the drawing processing unit 71 displays the placed tag at the designated coordinates, and adjusts the coordinates of the tag in accordance with the user's operation such as drag and drop.
Further, the drawing processing unit 71 prompts the user to input a device address related to the input tag or the display tag.
As a result, the user operates the drawing processing unit 71 to
Screen data can be created simply by arranging tags at desired positions on the screen and associating each tag with an address of a device.

Therefore, the display and operation of each programmable display 4 can be determined (changed) more easily than when the display program of the programmable display 4 is modified, and the user of the control system 1 (the control host computer 6 User) can match the actual situation of the target system 2, the proficiency of the operator of the programmable display 4, or the preference of the user.

In the control program and the control data, the system program and the application program are changed by the protocol program or the application program.
Distribute recording media recording programs and data,
The information is transmitted to the user of the control system 1 through communication or the like, and is stored in the storage unit 72.

Further, the system management section 64 includes a destination management section 73 for managing to which programmable display 4 the control program and control data stored in the storage section 72 are to be transmitted. And a write confirmation unit 74 for confirming whether or not the control program or the control data thus written is normally written to the storage unit 44 of each programmable display 4.

When transmitting the control program or the control data to each programmable display 4, the transmission destination management unit 73 determines, among the data sequences to be transmitted to each of them, a common part in the data sequence to a plurality of transmission destinations. If so, the server unit 63 can be instructed to multicast or broadcast the common part to the plurality of destinations. As a result, since a data string can be transmitted to a plurality of programmable displays 4 at the same time, the occupation time and transmission time of the LAN 5 can be greatly reduced.

When the data sequence to each programmable display 4 is successively compared and a common portion is extracted, the boundary between the common portion and the non-common portion changes for each transmission destination or data sequence. After transmitting the common part separately, there is a possibility that the amount of calculation when combining is increased. Further, when the common portion is small, there is a possibility that the increase in the synthesis time is longer than the shortened transmission time. Therefore, the destination management unit 73 according to the present embodiment compares the control program and control data composed of a plurality of files in file units, and determines whether to transmit the same file to a plurality of destinations. It is determined that if the same file exists, the file is multicast or broadcast.

When the data strings are not common, the transmission destination management unit 73 sequentially transmits the data strings to the respective programmable displays 4 and before the programmable displays 4 report the writing success. However, when the transmission of the data sequence to a certain programmable display device 4 is completed, the server unit 63 can be instructed to transmit the data sequence to the next programmable display device 4. Thus, the time required for the entire process, that is, from the time when the transmission of the data sequence to the first programmable display device 4 is started, is shorter than the configuration in which the data sequence is transmitted to the next programmable display device 4 after waiting for the writing success report. , All programmable displays 4
From the time when the write success report is received.

On the other hand, the write confirmation section 74 is
When a report from each programmable display 4 is received via 3, based on the report, it is determined whether or not each has been successfully written. Further, when it is confirmed that the writing has been successfully performed on all the programmable displays 4, for example, the execution of the control program is instructed to each programmable display 4 to return to the normal control operation. Further, for example, when the programmable display 4 does not report the success of the writing even after a predetermined time-out time elapses, for example, when a power failure occurs after transmission of the data sequence, for example, the data sequence is transmitted to the transmission destination management unit 73 again. For example, a predetermined error process can be performed.

Since the LAN 5 according to the present embodiment is an Ethernet, the control host computer 6 includes a MAC address storage unit 62a and an IP address storage unit 62b, like the programmable display device 4.
The common protocol IF unit 62 stores the MA
C / IP address and TCP / IP
Communicate by protocol. However, since the control host computer 6 can use a general-purpose computer, and in many cases, the manufacturer is different from the programmable display 4, the control host computer 6 stores the MA stored in the MAC address storage unit 62a.
The vendor ID of the C address is different from the vendor ID of the programmable display 4.

Further, the control host computer 6 is provided with an address setting section 65 for generating an IP address of the own device with reference to the MAC address storage section 62a and storing the generated IP address in the IP address storage section 62b. Similarly to the address setting unit 46 of the programmable display 4, the address setting unit 65 includes, among the MAC addresses of its own device,
The lower 32 bits are extracted and set as the IP address of the own device. However, in the control system 1 according to the present embodiment, when the generated IP addresses are duplicated, the address setting unit 46 of the programmable display 4 changes the IP address of its own device to avoid duplication. Therefore, the address setting unit 65 of the control host computer 6 stores the generated IP address as it is in the IP address storage unit 62.
b.

The above members 41 to 46, 61 to 74
Can be realized only by hardware, but in the present embodiment, the arithmetic means such as the CPU
Executing a program stored in storage means such as a touch panel, an input / output means such as a liquid crystal display device, or
It is implemented as a functional block realized by controlling a communication circuit such as an interface circuit.
Therefore, a computer having these means can store the program on a recording medium (for example, CD-RO).
M and the like, and only by executing the program, the programmable display 4 and the control host computer 6 according to the present embodiment can be realized. In addition, for example, a serial cable, LAN5, or, for example,
If a program for downloading a program via another communication path such as the Internet is installed in the computer in advance, the program can be distributed to the computer via the communication path.

The operation of each unit when the control host computer 6 transmits a control program or control data in the above configuration will be described below with reference to FIGS. For example, when transmitting the control data or the control data, for example, when the control program is updated, when the transmission is instructed by, for example, a user operation, the transmission destination management unit of the control host computer 6. At step 1 (hereinafter abbreviated as S1) 73 shown in FIG. 4, a datagram for instructing the server unit 63 to instruct each programmable display 4 to set an IP address is transmitted to the LAN 5. Broadcast (broadcast).

Here, the common protocol IF unit 62
Since the communication is performed by the CP / IP protocol, the datagram contains the IP address of the control host computer 6 as the source address. When the datagram is broadcast, each programmable display 4 receives the datagram regardless of its own IP address. As a result, the control host computer 6 sends each programmable display 4 to each programmable display 4 without knowing the IP address of each programmable display 4.
The IP address of the control host computer 6 can be notified.

On the other hand, in S2, upon receiving the datagram, the common protocol IF unit 42 of each programmable display 4 instructs the address setting unit 46 to set an IP address. In response, the address setting unit 46
Automatically generates an IP address from the MAC address of the own device.

Specifically, in S11 shown in FIG.
The address setting unit 46 stores the serial number of its own MAC address in the area A1 of the IP address storage unit 42b. In step S12, the address setting unit 46 stores the lower 8 bits of the vendor ID of the own device in the area A2 of the IP address storage unit 42b. Further, the IP address set in S11 and S12 is the same as the IP address of the control host computer 6 transmitted in S1 of FIG.
If it matches the P address (YES in S13), the value of the area A2 in the IP address storage unit 42b is changed and adjusted (S14). If they do not match,
The value of the area A2 is not changed. Therefore, when determining the IP address of the own device, each programmable display 4 can set a unique IP address on the LAN 5 even though it is not communicating with another programmable display 4.

When a device that does not have the address setting unit 46, such as a network printer that prints in response to an instruction from the control host computer 6, is connected to the LAN 5, the IP address of the device is set to the user's IP address. In accordance with the instruction, the values are set so that the values cannot be set by the address setting sections 46 and 65 of each programmable display 4 and the control display device.

In S2 (S11 to S14), when the respective IP addresses are stored in the IP address storage section 42b of each programmable display 4, the common protocol IF section 42 of each programmable display 4 In S3 shown in FIG. 4, a datagram indicating that an IP address has been set is broadcast, and the control host computer 6 is notified of its own IP address. Instead of the broadcast, the datagram may be transmitted to the IP address of the control host computer 6 notified in S1.

On the other hand, when receiving the respective IP addresses from the respective programmable displays 4, the transmission destination manager 73 of the control host computer 6 displays, for example, the names of the respective programmable displays 4 in S4. For example, the user is prompted to select a transmission destination. Examples of the name include a model name of the programmable display 4 and a nickname such as “programmable display for line 1”. The name of each programmable display 4 is stored in advance in each programmable display 4, and the control host computer 6 executes, for example, S3
And may be obtained by communicating with each programmable display 4 based on the IP address obtained in. Also,
In the above S3, if the datagram transmitted by each programmable display 4 includes the respective name,
It may be extracted and acquired from the datagram. In this case, there is no need to communicate after sending the datagram,
The amount of data flowing through the LAN 5 can be reduced, and the time required for acquisition can be reduced.

When the user selects the destination programmable display 4 in S4, the destination management unit 73 sets
In step S5, the program is instructed to the server unit 63 to transmit a control program or control data to each of the selected programmable displays 4. In step S6, each programmable display 4 sends the control program or control data to the corresponding storage unit 44. Write the program or control data. Further, in S7,
The write confirmation unit 74 of the control host computer 6
When a write success report is received from each programmable display 4, the above-described write processing of S1 to S7 ends.

The timing at which the processes of S5 to S7 are performed will be described in detail. For example, when the system program of the control program is updated, the control program or the control data is transmitted to each programmable display 4. At the time of transmission, if the data string to be transmitted to each is common, the destination management unit 73 causes the data strings to be simultaneously transferred to each programmable display 4 as shown in FIG. 6 (period t1 to t2).

Here, in the LAN 5, the transmission destination is identified by the IP address, and the device on the receiving side receives the datagram having the IP address of the own device as the transmission destination in the data stream flowing through the LAN 5. Therefore, the management unit 7
3 instructs the server unit 63 to broadcast or multicast, the common protocol IF unit 62 of the control host computer 6 is connected to the LAN 5 by a single connector, and communication from the control host computer 6 to each programmable display 4 is performed. Although at least part of the path is shared between the programmable displays 4, the control host computer 6 can simultaneously transfer a data string to each programmable display 4.

On the other hand, when each programmable display device 4 receives the data string addressed to itself, it writes the data string into the respective storage section 44 (period t2 to t3). Further, the programmable display 4 stores the data string in the storage unit 44.
When the data is normally written to the control host computer 6,
Report successful write to. However, the datagram containing the data indicating the successful writing is transmitted to the control host computer 6 from each programmable display 4 as a transmission source.
Cannot be transferred on the LAN 5 at the same time. Therefore, the write success report from each programmable display 4 is sequentially transmitted to the control host computer 6 (period from t3 to t4).

Further, the write confirmation section 74 of the control host computer 6 receives the sequentially transmitted write success reports and confirms that all the programmable displays 4 that have transmitted the data sequence have completed the write normally ( At the point of time t4), the process ends. On the other hand, if a write success report cannot be received even after a predetermined time-out period has elapsed since the data string transfer was terminated due to, for example, a power failure after the data string transfer, the write confirmation unit 74 performs a predetermined error process such as reporting to the user or transmitting a data string again. In the example of FIG. 6, since the data string is simultaneously transferred and the write success report is sequentially transferred, the timeout time is the required time of the write success report x the number of transferred programmable displays 4 + the required time of the write. Set to a value that exceeds.

On the other hand, when the data strings to be transmitted to the respective programmable displays 4 are different from each other, for example, when the screen data is transmitted to the programmable displays 4 which perform different display / control operations, the transmission destination management unit 73 As shown in FIG. 7, after the data transfer to a certain programmable display 4 is completed, the server unit 63 is instructed to transfer the data to the next programmable display 4 without waiting for a write success report. In this case, when the data sequence is transmitted to the first programmable display 4 during the period from t11 to t12, the data sequence is transmitted to the first programmable display 4 during the period from t12 to t13. The program is stored in the storage unit 44, and a write success report is sent from the programmable display 4 to the control host computer 6 during a period from t13 to t14. On the other hand, when the transfer of the data sequence to the first programmable display device 4 is completed (at time t12 and t21), the control host computer 6 transfers the data sequence to the second programmable display device 4 (t21 to t21). t22). further,
After writing the data string to the storage unit 44, the second programmable display 4 notifies a write success report.

For example, as in the case of transmitting an application program such as a runtime and screen data, a control program or control data to be transmitted includes a common part between a plurality of programmable displays 4,
If there is a different part for each programmable display 4, the destination management unit 73 causes the common part to be transmitted at the timing of FIG. 6 and the non-common part to be transmitted at the timing of FIG.

Here, as a comparative example, similarly to the case where a control program and control data are written to a single programmable display 4, a data string is transferred to a certain programmable display 4 and In the configuration in which the processing of the next programmable display 4 is started after receiving the writing success report, the processing is performed as shown in FIG. In this case, the time required for data string transfer is Tt, the time required for writing to the storage unit 44 is Tw,
Assuming that the time required for the writing success report is Tr, the time T required for writing the control program and the control data to each of the n programmable displays 4 (the time required for the entire processing) T is (Tt + Tw + Tr) · n Becomes Here, in the programmable display 4, since a nonvolatile semiconductor memory is used as a recording medium of the storage unit 44,
The writing time Tw is long. Therefore, as the number of programmable displays 4 to be written increases, the required time T of the entire process increases steeply.

In particular, in the control system 1, the number of the programmable displays 4 is large, and the update times of the programmable displays 4 substantially coincide with each other, for example, when the system program of the control program is updated. Many.
Further, in the control system 1, since the operation stop is directly linked to an accident or a deterioration in business performance, it is necessary to prevent an unexpected operation stop compared to OA equipment, and even if the operation stop cannot be avoided, Immediate recovery is required. As a result, the damage caused by the increase in the required time T becomes extremely large.

On the other hand, in the control system 1 according to the present embodiment, even if the data strings transmitted to the respective programmable displays 4 are different from each other, as shown in FIG. 6 completes the transfer of the data string to a certain programmable display 4, and starts the transfer of the data string to the next programmable display 4. As a result, the writing period of the data string in a certain programmable display 4 is changed to the next programmable display 4
Overlaps with the data string transfer period. Therefore, the storage unit 4 can be operated normally in a poor environment.
As a result of using a non-volatile semiconductor memory as the recording medium of No. 4, despite the fact that the write time of the data string is longer than the transfer time of the data string, the required time T of the entire process is n · Ts + Tw + Tr And the damage caused by the increase in the required time T can be reduced.

In the above configuration, each programmable display 4
Generates a unique value on the LAN 5 as the IP address of the own device in response to an instruction from the control host computer 6. Therefore, TCP / IP on LAN5
Despite the high-speed communication using the protocol, the user of the control system 1 can set the IP address of the control host computer 6 and each programmable display 4 without setting the IP address, thereby reducing the user's labor. .

It is to be noted that, for example, a device different from the programmable display 4 and the control host computer 6 is a LAN 5
It is desirable that the address setting units 46 and 62 can select operation / stop of operation in case that the user sets the IP address of each programmable display 4. Thereby, when the user is not used to the network, the address setting unit 46.
62 automatically sets the IP address of the programmable display 4 and the control host computer 6, and when the user becomes accustomed to the network, can set the IP address according to the user's instruction. In this case, regardless of before and after the operation / stop of the operation, since the LAN 5 communicates by the TCP / IP protocol, there is no need to change the communication program of the control host computer 6 or the programmable display 4. Therefore, when the scale of the network configuration is expected to expand, a management program that communicates using the TCP / IP protocol can be used from an earlier point in time.

In the present embodiment, the name of the programmable display 4 is also presented when prompting the user to select the programmable display 4 to be transmitted. Therefore, the IP address composed of a series of numbers can be hidden from the user of the control system 1. As a result, it is possible to realize the control system 1 that is easy for a user who is not used to the network to be familiar with.

In the above description, the programmable displays 4 in the control system 1 have the same vendor ID, and each address setting section 46 has a part (lower 8 bits) of the vendor ID of its own device. IP address area A2
Has been described as an example, but is not limited to this. In the case of the same vendor ID, the same effect can be obtained even if it is set to a predetermined specific value. In particular, when "10" is selected as a specific value, the network address generated by the programmable display 4 is a private address (10.xx.xx.xx). As a result,
Even if the control system 1 is provided with an inter-network connecting device such as a router, it is possible to prevent a packet transmitted in the LAN 5 from flowing out of the LAN 5 without special setting for the inter-network connecting device.

The vendor I of the programmable display 4
Even if D is different from each other, the vendor ID of each programmable display 4 is included in the predetermined vendor ID group, and the number of vendor IDs in the vendor ID group is the number that can be set in the area A2. If the number is smaller than the address, the address setting unit 46 of each programmable display 4 checks the vendor I of its own device.
What is necessary is just to set the value according to D in area A2. In this case, the address setting unit 46 refers to a storage area in which a value corresponding to the vendor ID of the own device is stored in advance, or stores in advance a correspondence table between the vendor IDs of the group of vendor IDs and the set values. If a value different from the value set by the address setting unit 46 provided in the programmable display 4 of the vendor ID different from the own device is set by referring to the correspondence table, the same as in the present embodiment. , LAN5, a unique value can be set. Note that even in this case, the vendor ID
Since the number of vendor IDs in the group is smaller than the number that can be set in the area A2, when adjusting the value of the area A2, the vendor I
It can be adjusted to a value that does not correspond to any of D.

Further, in the present embodiment, the value of the area A1 (first value) and the value of the area A2 (second value) are connected to form
Although the P address is created, it is not limited to this. For example, the IP address may be generated by arranging each bit of the first value and each bit of the second value in a predetermined order.
Regardless of the derivation method, if the combination of the first value and the second value is different, the same effect can be obtained as long as the derivation method has different values. Further, the method of deriving the first value is not limited to the method of using the serial number itself of the own device, but adding or subtracting a predetermined value to or from the serial number, and deriving the value by shift or logical operation for each bit. May be. Regardless of the derivation method, the same effect can be obtained as long as the derivation method is a value according to the serial number of the own device and a value different from the value according to the other serial number. .

Further, in the present embodiment, based on whether or not the IP address generated by the address setting unit 46 and the IP address of the control host computer 6 match,
Although it is determined whether to adjust the second value, the present invention is not limited to this. For example, in the derivation method of this embodiment, I
If the values of the area A2 among the P addresses are different from each other, there is no possibility that both IP addresses match. Therefore, the value of the area A2 is extracted from the IP address of the control host computer 6, and the value of the area A2 derived by the address setting unit 46 is compared with the extracted value to determine the possibility of coincidence. Is also good.

In this case, the value of the area A2, that is, the second
In order to determine the possibility that the IP addresses match based only on the value, the address setting unit 46 may adjust the adjustment of the second value in the plurality of programmable displays 4 having the same vendor ID. However, even in this case, since the serial numbers of the programmable displays 4 are different from each other, each programmable display 4 can set a unique value in the LAN 5 without any problem.

In the above description, the drawing processing unit 71 is used as a member capable of changing the control program or control data.
Only the control program and the control data, such as a system program, a protocol program, or an application program, are changed by a computer such as a manufacturer of the programmable display 4 and then distributed or communicated with a recording medium. Although the case where the program is stored in the storage unit 72 is illustrated by the above, these programs may be changed by the control host computer 6.

Furthermore, in the present embodiment, the case where the LAN 5 is configured by Ethernet has been described, but the present invention is not limited to this. Further, the control system 1 has been described as an example, but the present invention is not limited to this. It consists of a combination of a vendor ID indicating each manufacturer and a serial number whose bit width is smaller than a unique network address in the local area network. If the network device is connected to a LAN that communicates by using the same, substantially the same effect can be obtained. However, in the case of the control system, the manufacturer of the control display device such as the programmable display 4 is often limited. In addition, a single host computer and one or more control display devices are often connected via a LAN. Therefore, it is particularly suitable when the network device is a control display device.

[0070]

As described above, when the network device according to the first aspect of the present invention receives the instruction for self-generation of the network address, the network device generates the network address by referring to the hardware address storage means of the self-device. A first value having a value corresponding to the identification number of the own device and different from a value corresponding to the other identification number, and a first value of the own device. Depending on the vendor identifier, and based on a combination of a predetermined value and a second value of a predetermined value that is different from a value corresponding to another vendor identifier of a predetermined vendor identifier group, if the combination is different, A network address setting means for setting a network address to a value different from each other; If the network address that is set determines that there is a possibility that the same value as the network address indicating the source of the self-generation instruction by,
Second value adjusting means for instructing the network address setting means to change the second value to a predetermined value different from any of the values corresponding to the vendor identifiers of the group of vendor identifiers is provided. Configuration.

In the above configuration, the local equipment including the network device having the specific vendor identifier or the vendor identifier of the specific vendor identifier group and the transmission source of the self-generation instruction are provided.
In the area network, although the user of the local area network does not specifically set,
After receiving a self-generation instruction from the host computer, each network device uses a unique value in the local area network as its own network address without communicating with other network devices or the host computer. Can be set. As a result, there is an effect that the trouble in managing the local area network can be greatly reduced.

According to the second aspect of the present invention, as described above, in the configuration of the first aspect of the present invention, the network device is a control display device for displaying a state of a control target. is there.

Here, manufacturers of the control display devices are limited, and many control display devices are connected to a host computer via a local area network in a control system in many cases. Therefore, by providing the control display device with each means of the network device,
This has the effect of greatly reducing the labor required for managing the local area network of the control system.

As described above, the recording medium according to the third aspect has a configuration in which a program for operating the computer is recorded as each means according to the first aspect.

When a program is read from the recording medium having the above configuration and executed by the computer, the computer operates as the network device according to the first aspect. As a result, similar to the first aspect, the time and effort for managing the local area network including the network device having the specific vendor identifier or the vendor identifier of the specific vendor identifier group and the transmission source of the self-generation instruction are reduced. This has the effect of being able to significantly reduce.

[Brief description of the drawings]

FIG. 1 illustrates one embodiment of the present invention, and is a block diagram illustrating a main configuration of a control system.

FIG. 2 is a connection diagram showing a connection relationship between devices of the control system.

FIG. 3 is an explanatory diagram showing a relationship between an IP address set by the control system and a MAC address.

FIG. 4 is a flowchart showing an operation of the control system.

FIG. 5 is a flowchart showing an operation of the control system and showing an IP address generation operation in the programmable display device in detail.

FIG. 6 is a timing chart showing a transmission method when the same data is transmitted to each programmable display in the control system.

FIG. 7 is a timing chart showing a transmission method when data transmitted to each programmable display device is different from each other in the control system.

FIG. 8 shows a comparative example of the present invention, and is a timing chart showing a method of transmitting data to each programmable display.

FIG. 9 illustrates a conventional example, and is a connection diagram illustrating a conventional network system.

[Explanation of symbols]

Reference Signs List 4 Programmable display device (network device; display device for control) 5 Local area network 42a MAC address storage unit (hardware address storage unit) 46 Address setting unit (network address generation and setting unit; determination unit and second value adjustment means)

Claims (3)

[Claims] And a hardware address storing means for storing a hardware address comprising a combination of a vendor identifier indicating a manufacturer and an identification number for distinguishing devices having the same vendor identifier. A network device that has a wide bit width and is connectable to a local area network that specifies a source and a destination of data based on a network address assigned to data to be transmitted; When a self-generation instruction of a network address is received via the hardware address storage unit, the network address generation unit includes a network address generation unit that self-generates a network address of the own device with reference to the hardware address storage unit. Set the value according to the device identification number. Also, a first value of a value different from the value corresponding to the other identification numbers, depending on the vendor identifier of the device,
Further, based on a combination of a predetermined value and a second value of a predetermined value that is different from a value corresponding to another vendor identifier of a predetermined vendor identifier group, if the combination is different, the values are different from each other. Network address setting means for setting a network address to such a value, and whether the network address set by the network address setting means may be the same as the network address indicating the transmission source of the self-generation instruction When determining that there is a possibility that the value may be the same as the determination value, the second value is changed to a predetermined value different from any of the values corresponding to the vendor identifiers of the vendor identifier group. And a second value adjusting means for instructing the network address setting means to perform the setting. Ttowaku equipment. 2. The network device according to claim 1, wherein the network device is a control display device for displaying a state of a control target. 3. A hardware address storing means for storing a hardware address comprising a combination of a vendor identifier indicating a manufacturer and an identification number for distinguishing devices having the same vendor identifier. Recording a computer having a wide bit width and a network address setting program for a computer connectable to a local area network for specifying a source and a destination of data based on a network address assigned to data to be transmitted. A recording medium, characterized in that a program for operating the computer is recorded as each means according to claim 1.