JPH04192833A - Communication network system - Google Patents

Abstract

PURPOSE:To facilitate the allocation of an address to a communication station connected to a network by providing an address request part for requesting an address allocation to the communication station, and providing an address managing part and an allocation answer part on a host computer. CONSTITUTION:A host computer 10 and a communication station 20 are provided, and connected to a communication circuit 30, respectively. The host computer 10 is provided with a network access part 11, a data discriminating part 12, an address managing part 13, an address information storage part 14, an allocation answer part 15, an address confirming part 16, and a timer control part 17. Also, the communication station 20 is provided with a network access part 21, an address request part 22, a timer control part 23, and an address informing part 24. In such a way, an allocation of an address to the communication station connected to the network is executed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication network system, and particularly to a communication network system in which communication stations connected to a network are often added/deleted.

[Prior Art] In a communication network system in which a host computer and a plurality of communication stations are connected via a communication line, each of the host computer and the plurality of communication stations has a address is assigned. This address is managed by the host computer.

When adding or deleting a communication station in this system, it is necessary to change the address information stored in the host computer.

Conventionally, addresses in this type of communication network system have been manually managed by assigning addresses each time a communication station is added or deleted. Further, an address is determined in advance when a communication station is added, and the address is set before connection to the network is performed.

[Problems to be Solved by the Invention] However, since conventional address assignment is managed manually, there is a problem that the larger the network configuration itself becomes, the more time and effort it takes to assign addresses.

Another problem is that human error is likely to occur, such as double assignment of the same address to different stations.

Furthermore, when setting an address for a communication station, a setting error may be made, and there is also the problem that the communication station cannot be added to the network immediately.

[Means for Solving the Problems] According to the present invention, there is provided one host computer and a plurality of communication stations connected to a communication line, and an address is assigned to each of the host computer and the plurality of communication stations. , a communication network system in which each of the host computer and the plurality of communication stations can communicate with one or more of the host computer and the plurality of communication stations via the communication line, wherein the plurality of communication stations each includes a first network access means that is connected to the communication line and sends and receives data, and an address assignment request signal that requests the host computer to assign an arbitrary address via the first network access means. address requesting means for outputting an address allocation permission signal from the host computer and receiving an address allocation permission signal from the host computer; and a first address requesting means for outputting a time-up signal to the address requesting means when a predetermined time elapses after being activated by the activation signal from the address requesting means. a timer control means; the host computer has a second network access means connected to the communication line for transmitting and receiving data; an address information storage means for storing the address as address information; Upon receiving the request signal, compare the address information with the arbitrary address, and if the address information does not include the arbitrary address, output a permission instruction signal instructing permission for address allocation, and update the address information. A communication network system is obtained, comprising: address management means for performing the above-mentioned permission instruction signal; and allocation response means for receiving the permission instruction signal and transmitting an address allocation permission signal to the communication line via the network access means.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows a block diagram of one embodiment of the invention.

The communication network system of this embodiment includes a host computer 10 and a communication station 20, each of which has a communication line 3.
Connected to 0.

The host computer 10 has a network access unit 1
1, data identification section 12, address management section 13, address information storage section 14, allocation response section 15, address confirmation section 16
, and a timer control section 17.

The network access unit 11 is connected to the communication line 30 and sends and receives data to and from the network. The data identification unit 12 identifies data received by the network access unit 11. The address management section 13 is connected to an address information storage section 14 that stores address information 18, and performs various processes. The allocation response unit 15 outputs an address allocation permission signal according to an instruction from the address management unit 13. The address confirmation section 16 reads out the address information 18 via the address management section 13 and outputs an address confirmation signal to the communication station 20. The timer control unit 17 provides the address confirmation unit 16 with timing for starting operation and timing for waiting for an address notification signal from the communication station 20 to time out.

The communication station 20 also includes a network access section 21, an address request section 22, a timer control section 23, and an address notification section 24.

The network access unit 21 is connected to the communication line 30 and sends and receives data to and from the network. Also,
Identify the type of data received.

The address request unit 22 outputs an address allocation request signal to the host computer 10 via the network access unit 21. The timer control unit 23 defines the waiting time from when the address allocation request signal is output to when the address allocation permission signal is received. The address notification unit 24 outputs an address notification signal when receiving an address confirmation signal from the host combination computer 10.

Next, the data link layer shown in JIS

FIG. 2 shows an example of the structure of the address information 18, in which the identifier is set to 1 when an address is assigned, and the identifier is set to 0 when the address is in an empty state.

FIG. 3 shows the frame format of the transmission signal used in ISO580273. This frame has a destination address (DA
), a source address (SA), an information field, and a frame check sequence (FCS).

The communication station 20 newly connected to the network first
A request is made to the host computer 10 to allocate an address. That is, the address requesting unit 22 of the communication station 20,
An address request signal is generated by storing the address of the host computer 10 in the destination address, storing the address for which allocation is requested in the source address, and storing information indicating that it is an address request in the information field. Then, an address request signal is transmitted onto the communication line 30 via the network access section 21.

In the host computer 10, the network access section 1
The data identification unit 12 refers to the information field of the frame received by the device 1 and determines whether it is an address request, an address notification, or something else.

The signal determined by the data identification unit 12 to be an address request is input to the address management unit 13.

The address management section 13 refers to the address information 18 in the address information storage section 14 to check whether the requested address has already been assigned. As a result, the host computer does nothing when the requested address is already assigned to another communication station.

When the requested address is vacant, the address management unit 13 rewrites the address information 18 and
The allocation response unit 15 is activated.

The assignment response unit 15 generates an address assignment permission signal that stores the requested address in the destination address, the address of the host computer 10 in the source address, and information indicating that it is an address assignment response in the information field. Then, an address allocation permission signal is transmitted onto the communication line 30 via the network access unit 11.

When the communication station 20 side sends an address assignment request signal,
The timer control unit 23 is activated. The timer control section 23 outputs a time-up signal to the address request section 22 when a predetermined time has elapsed. That is, the waiting time for an address allocation permission signal from the host computer 10 is defined.

If the address request section 22 receives the address allocation permission signal before receiving the time-up signal from the timer control section 23, it stops the timer control section 23. The communication station 20 is now connected to the network.

If the address permission signal cannot be received and a time-up signal is received from the timer control unit 23, the operation of outputting an address allocation request signal requesting allocation of an address different from the previously transmitted address is repeated.

Next, address management when a communication station is deleted from the network will be explained. In this embodiment, the host computer 10 outputs an address confirmation signal to the communication station 20 at predetermined intervals, and the address information 18 of a communication station without an address notification signal is corrected, assuming that the communication station has been deleted. This operation will be explained in detail below.

On the host computer 10 side, the timer control unit 17 outputs a confirmation start signal at predetermined intervals.

Upon receiving the confirmation start signal, the address confirmation section 16 activates the address management section 13 and reads out the address information 18. Then, in order to check whether the communication station 20 to which the address is being assigned is connected to the network, the destination address is the address to be checked, and the source address is the address of the host computer 10. In addition, an address confirmation signal is generated in which the information field stores information indicating that the address is confirmation. The generated address confirmation signal is transmitted onto the communication line 30 via the network access section 11.

When the communication station 20 receives the address confirmation signal, the address notification section 24 is activated. The address notification unit 24 stores the address of the host computer 10 in the destination address, stores the own station (communication station 20) address in the source address, and stores information indicating that the address notification is an address notification in the information field. generate. Then, an address notification signal is transmitted onto the communication line 30 via the network access unit 21.

In the host computer 10, the data identification unit 12 refers to the information field of the received frame and determines whether it is an address notification, an address request, or something else. and,
If it is an address notification, the address confirmation unit 16 receives the input, and the address confirmation unit 16 determines that the corresponding address still exists on the network.

If there is no address notification by the time the time-up signal is output from the timer control section 17, it is determined that the corresponding address does not exist on the network, and the address information 18 is changed to indicate that the corresponding address is vacant.

FIG. 4 shows an example in which frames are exchanged between the host computer 10 and the communication station 20 when the communication station 20 requests address assignment and the host computer 10 confirms the address.

The communication station 20 transmits an address assignment request 41 when requesting the host computer 10 to assign an address. When the host computer 10 receives the address assignment request 41, it does not return assignment permission if the requested address has already been assigned to another communication station.

If the communication station 20 does not receive an allocation permission even after the allocation response monitoring time (tl) has elapsed, it makes an address allocation request 42 using an address different from the address requested in the address allocation request 41. If the address requested by the address allocation request 42 is vacant, the host computer 10 transmits an allocation permission 43 to the communication station 20.

When the communication station 20 receives the assignment permission 43, it determines that the address has been assigned.

On the host computer 10, address assignment permission 43
At the time when the address is sent, a presence monitoring time (t2) is started to identify whether the address exists or not. The host computer 10 transmits an address confirmation 44 when the presence monitoring time (t2) times out, and confirms the presence to the communication station 20.

When the communication station 20 receives the address confirmation 44, it returns an address notification 45 to notify that its own station exists on the network.

When the host computer 10 receives the address notification 45, the communication station 2 having the address that sent the address confirmation 44
It is determined that 0 exists. Furthermore, upon receiving the address notification 45, the host computer 10 starts the existence monitoring time (t2) again. When the presence monitoring time (t2) times out, the host computer 1 transmits an address confirmation 46 to the communication station 20 again to confirm the presence. If the host computer 1 does not receive an address notification within the acknowledgment monitoring time (t3), it considers that the communication station 20 with the corresponding address does not exist.

FIG. 5 is a diagram illustrating the exchange of data and control signals between various parts within the host computer 10.

First, we will explain what happens when an address assignment request is received.

When the network access unit 11 receives the address assignment request 51, the network access unit 11 notifies the data identification unit 12 of data reception 52. Data identification part 1
2 identifies that the received data is an address request, and notifies the address management section 13 of address request reception 53.

Address management unit] 3 sends address information 1 to address information storage unit 14 when address request reception 53 is input.
8, a read 54 is issued. The address information storage unit 14 sends address information to a data notification 55.
The address management unit 13 is notified of this.

The address management unit 13 compares the read address information 18 with the requested address, and if the address is free, instructs the allocation response unit 15 to send an allocation response 56. The allocation response unit 15 requests the network access unit 11 to send allocation permission through data transmission 57. The network access unit 11 transmits an allocation permission 58.

Next, address confirmation will be explained.

The timer control unit 17 notifies the address confirmation unit 16 of a timeout notification 59. When the address confirmation unit 16 receives the timeout notification 59, it issues a readout 60 to the address management unit 13 in order to know the address whose existence should be confirmed.

The address confirmation unit 13 similarly issues a read 61 to the address information storage unit 14. Address information storage section 1
4 notifies address information to the address management section 13 by data notification 62. The address management section 13 notifies the address confirmation section 16 of the address information through a data notification 63. The address confirmation unit 16 is the network access unit 1
By issuing a data transmission 64 to the address 1, an address confirmation 65 transmission instruction is issued. Network access section 11
sends an address confirmation 65 on line 30.

The address confirmation unit 16 sends the timer request 66 to the timer control unit 1.
7, the timer 17 that monitors the response is activated.

When the network access unit 11 receives the address notification 67, the data identification unit 12 is notified of data reception 68. When the data identification unit 12 identifies the address notification, the address notification reception 69 sends the address notification to the address confirmation unit 1.
6 will be notified. When the address confirmation unit 1β recognizes that it is a response to the previously transmitted address confirmation 65, the timer re-counting 70 is sent to the timer control unit 17 to stop the response monitoring timer and start the presence confirmation monitoring timer.
request.

Further, when the timer control unit 17 notifies the address confirmation unit 16 of a timeout notification 71, the address confirmation unit 16 issues a read 72 to the address management unit 13 in order to know the address whose existence should be confirmed. . The address confirmation unit 13 similarly issues a read 73 to the address information storage unit 14. The address information storage unit 14 passes address information to the address management unit 13 by data notification 74. The address management section 13 is the address confirmation section 16
Address information is notified to the address information in data notification 75. The address confirmation unit 16 instructs the network access unit 11 to send an address confirmation 77 by issuing a data transmission 76 . Then, the network access unit 11 transmits an address confirmation 77 onto the line 30.

The address confirmation unit 16 sends the timer request 78 to the timer control unit 1.
7, a timer is started for monitoring the response. No response was obtained, and the timer control unit 1
From 7, response monitoring timeout is timeout notification 79
When the address confirmation unit 16 is notified by , the address confirmation unit 16 considers that the corresponding address does not exist on the network. The address confirmation unit 16 requests the address management unit 13 to delete data 80, and the address management unit 3 performs data deletion 81 on the address information storage unit 14.

FIG. 6 is a diagram showing the exchange of control between each section in the communication station 20. As shown in FIG.

In the communication station 20, when requesting address assignment, the address request section 22 issues a timer start 90 to the timer control section 23 in order to monitor the response return time. At the same time, the address request section 22 requests the network access section 21 to transmit data 91 . The network access unit 21 transmits an address assignment request 92 onto the line 30. The timer control unit 23 issues a timeout notification 93 to the address requesting unit 22 when the time requested by the timer activation 90 has elapsed. When the address requesting unit 22 receives the timeout notification 93, it determines that the previously requested address allocation request 92 was not accepted by the host computer 10. Then, a timer activation 94 is issued to the timer control unit 23 in order to monitor the response return time for requesting an address different from the address requested in the address allocation request 92. The address request unit 22 simultaneously performs data transmission 95 to the network access unit 21.

The network access unit 21 transmits an address assignment request 96 onto the line 30.

The network access unit 21 is the host computer 10
When receiving the assignment response 97 from
Notify. The address request unit 22 determines that the requested address has been accepted by the data reception 98,
A timer stop 99 is issued to the timer control unit 23.

When the network access unit 21 receives the address confirmation 100 from the host computer 10, the network access unit 21 notifies the address notification unit 24 of data reception 101.

The address notification unit 24 issues a data transmission 102 to the network access unit 21 in order to return the address notification. Then, the network access unit 21 transmits the address notification 103 onto the line.

FIG. 7 shows the address management section 13 of the host computer 10.
2 is a flowchart of the process of comparing the requested address and address information and registering the address information.

The address management unit 13 is activated by receiving an address allocation request in step Stl. Next, the address management unit 13 reads information from the address information storage unit 14 in step St2. Next, the address management unit 13 determines whether the requested address is vacant in step St3.

If the requested address is not available, the process jumps to step St6 and ends the process. If the requested address is vacant, the information in the address information storage section is changed in step St4. Then, in step St5, the network access unit 21 is instructed to send allocation permission, and the process ends (step 5t6).

[Effects of the Invention] As explained above, the present invention provides a communication station with an address requesting means for requesting address allocation, and a host computer with an address management means and an allocation response means, thereby improving communications connected to a network. Addresses can be easily assigned to stations.

In addition, the host computer is provided with a timer control means and an address confirmation means, and the communication station is provided with an address notification means, and the communication station is configured to check whether or not it is connected to the network at predetermined intervals. Addresses that are no longer assigned are automatically deleted.

As described above, the present invention has the effect of enabling dynamic addition/deletion of addresses.

[Brief explanation of the drawing]

Figure 1 is a block diagram of one embodiment of the present invention, Figure 2 is a diagram showing an example of address information, and Figure 3 is l5O8802/3.
4 is a sequence diagram of data transmitted between the host computer and the communication station, and FIG. 5 is a diagram for explaining the flow of control and data within the host computer. FIG. 6 is a diagram for explaining the flow of control at the communication station, and FIG. 7 is a flowchart of processing when the address management unit of the host computer receives an address request. DESCRIPTION OF SYMBOLS 10... Host computer, 11... Network access section, 12... Data identification section, 13... Address management section, 14... Address information storage section, 15.
... Assignment response section, 16... Address confirmation section, 17
...Timer control unit, 18...Address information, 20.
...Communication station, 21...Network access section, 22
...Address request section, 23...Timer control section, 24
...Address notification section, 30...Communication line, 41...
・Address assignment request, 42...Address assignment request, 4
3...Allocation permission, 44...Address confirmation, 45
...Address notification, 46.Address confirmation, 51.
...Address assignment request, 52...Data reception, 53.
...Receive address request, 54... Read, 55...
・Data notification, 56... Allocation permission transmission, 57...
・Data transmission, 58...Allocation permission, 59...Timeout notification, 60...Reading, 61...Reading, 62...Data notification, 63...Day, evening notification, 64... Data transmission, 65...Address recognition, 6
6...Timer request, 67...Address notification, 68.
...Data reception, 69...Address notification reception, 70.
...Timer re-counting, 71...Timeout notification, 72
...Read, 73...Read, 74...Data notification, 75...Data notification, 76...Data transmission, 77...Address confirmation, 78...Timer request, 7
9...Timeout notification, 80...Data deletion, 8
1...Delete data, 90...Start timer, 91...
・Data transmission, 92...Address request, 93...Timeout communication, 94...Timer activation, 95...Data transmission, 96...Address request, 97...Assignment response, 98... Data reception, 99...Timer stop, 100...Address confirmation, 101...Data reception, 102...Data transmission, 103...Address notification. Figure 2 DA: Destination Acjdr
ess <g destination ytrex)SA: 5ourc
eAddress catsycydrex)Fe
2: Frame Check 5equence
<-y frame inspection screen (:/2) M3 diagram host computer 10
Communication interval 20・) O r+= Ward pregnancy Figure 7

Claims (1)

[Claims] 1. It has one host computer and a plurality of communication stations connected to a communication line, each of the host computer and the plurality of communication stations is assigned an address, and the host computer and the plurality of communication stations are each assigned an address. In a communication network system in which each of the communication stations can communicate with the host computer and any one or more of the plurality of communication stations via the communication line, each of the plurality of communication stations a first network access means connected to the host computer for transmitting and receiving data; and an address assignment request signal for requesting the host computer to allocate an arbitrary address via the first network access means; address requesting means for receiving an address allocation permission signal from the address requesting means; and first timer control means for outputting a time-up signal to the address requesting means when a predetermined period of time has elapsed after being activated by the activation signal from the address requesting means. The host computer includes a second network access means that is connected to the communication line and performs data transmission and reception, an address information storage means that stores the address as address information, and a second network access means that is connected to the communication line and that stores the address as address information. address management means that compares the information with the arbitrary address and, when the arbitrary address is not included in the address information, outputs a permission instruction signal instructing permission for address allocation and updates the address information; A communication network system comprising: allocation response means for receiving the permission instruction signal and transmitting an address allocation permission signal to the communication line via the network access means. 2. The host computer includes a first timer control means that outputs a time elapsed signal at predetermined intervals, and upon receiving the time elapsed signal, reads out the address information via the address management means, and provides access to the second network. and address confirmation means for outputting an address confirmation signal through the means and receiving an address notification signal to instruct the address management means to update the address information, each of the plurality of communication stations Claim: further comprising an address notification means for outputting the address notification signal when the address confirmation signal is received via the network access means, and the address information is updated at every predetermined time. 1. The communication network system according to 1.