JPH0583270A - Network system and control program transfer method - Google Patents

Abstract

(57) [Abstract] [Purpose] A node that is directly or indirectly connected to the trunk ring does not need to have a control program, and the control program can be easily replaced, and an external storage device such as a hard disk can be installed. (EN) Provided is a network system having a communication control device of a small casing which is unnecessary. In a network system having at least two or more nodes for controlling communication and a transmission line connecting between the nodes, the above-mentioned node stores a control program during transfer of a control program for controlling communication. Of the above nodes, a node having a control program, which has disconnection means for logically disconnecting a connection with a node that is not transmitting / receiving, and connection means for making a one-to-one connection with a node transmitting / receiving a control program Has a transfer means for transferring the control program to another node, and the node for receiving the control program has a receiving means for receiving the transferred control program.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control device for a network system, and more particularly to a control program initial loading method, a replacement method and a device therefor.

[0002]

2. Description of the Related Art A ring type LAN (for example, FDDI: Fi)
ber Distributed Data Interface) is vulnerable to disconnection of the data way due to ring disconnection or device failure due to its configuration. Therefore, generally, a trunk ring is duplicated and a station management function (hereinafter, SMT; Station Manageme
(It is called nt) to improve the reliability of the network. The SMT performs configuration management, collection of statistical information, and the like, and therefore requires more software processing than hardware processing.

The devices that compose the ring include bridges, routers, concentrators (concentrators), workstations that can be directly connected to the dual ring, workstations that are connected to the dual ring via a branch line of the concentrator, etc. is there. M of OSI (Open System Interconnection) model
In a network system that has an AC (Media Access Control) layer and needs to perform station management, each device must have a control program for realizing SMT (Station Management). I have to. When starting up such a device, PMD (Physical Media Dependent),
At the same time as the initialization and activation of the hardware of PHY (Physical Layer protocol) and MAC layers, the control program must be loaded into the main memory and activated.

The conventional control program is activated by the following method.

(I) The control program is stored in a read-only memory (hereinafter referred to as ROM; Read Only Memory),
Built in each device. At startup, the built-in R
Load the program from OM into main memory. (Ii) Each device has a hard disk, and the control program is built in the hard disk. At startup, the program is loaded from the internal hard disk into main memory. (Iii) As disclosed in JP-A-2-263261, the control program on the hard disk of another device connected to the main ring is loaded into the main memory via the network.

[0006]

In the control program starting method as described above, (a) In the case of the above-mentioned conventional technique (i), when it is necessary to replace the control program, the ROM is rewritten or It will need to be replaced. (B) In the case of the above-mentioned conventional technique (ii), since all the devices must have a hard disk, the housing of the device becomes large. Moreover, when replacing the control program, the hard disks of all the devices must be rewritten. (C) In the case of the above-mentioned conventional technique (iii), since a device without a control program joins the trunk line ring at the time of program loading, the reliability of the entire ring is deteriorated and other devices are adversely affected. There is a risk of Such problems occur.

It is an object of the present invention that a device connected directly to a main ring or indirectly via a concentrator,
It is an object of the present invention to provide a network system having a small-sized communication control device which does not need to have a control program, can be easily replaced with a control program, and does not require an external storage device such as a hard disk.

[0008]

In a network system having at least two nodes for controlling communication and a transmission line connecting between the nodes, the nodes are:
When transferring a control program for controlling communication, disconnection means for logically disconnecting the connection with the node not transmitting / receiving the control program, and the connection for making a one-to-one connection with the node transmitting / receiving the control program And a node that has a control program among the above-mentioned nodes has a transfer unit that transfers the control program to another node, and a node that receives the control program has a receiving unit that receives the transferred control program. Have. The transmission line is duplicated, and the disconnecting means can be separated by folding back the duplicated transmission line.

The above-mentioned node is at least one of a wiring device accommodating one or more stations, a communication control device for controlling communication, and a station connected to the wiring device via a branch line of a transmission line. is there.

Further, the node further has means for confirming whether the versions of the control programs match, and when the versions of the control programs do not match, the control program can be transferred, and when they match, the nodes can not be transferred. ..

Further, the node further has a rewritable storage means in which the stored contents are not erased even when the power is turned off, and the storage means stores the control program received by the receiving means.

Further, the node can further have one or more control means for controlling transmission / reception according to the control program, and after the control program is executed, the disconnecting means and the connecting means for making a one-to-one connection are released. do it,
Join the network.

[0013]

In the network system of the present invention, the procedure until a node that does not have a control program joins the trunk ring is determined as follows.

When transferring a control program for controlling communication to another node, the node logically disconnects the connection with the node that does not transfer and makes a one-to-one connection with the transfer destination node for control. Transfer the program, and after transfer,
The one-to-one connection is terminated, the control program is started up, the disconnection is released, and the control program is transferred by the control program transfer method of joining the network. Before transferring the control program, the node judges whether the versions of the control program match or not,
If they do not match, transfer the control program.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

First, the configuration shown in the drawings will be described, and then the operation in each state will be described.

FIG. 1 shows an F-type LAN as a typical example of the ring-type LAN.
1 shows a standard configuration of a DDI network system. In FIG. 1, all devices (nodes) including stations on branch lines are connected to the FDDI trunk ring, and all devices are operating normally. In FIG. 1, 60
Is a transmission line, which is a double ring that constitutes a main line and has an active system and a standby system. 61 is a double ring 60
Of these, the active ring (primary ring) and 62 represent the standby ring (secondary ring) of the dual ring 60. If a failure occurs when using the active ring 61, it is possible to switch from the active ring 61 to the standby ring 62. Reference numeral 1 denotes a concentrator device (concentrator), which can be directly connected to the double ring 60. Communication control devices 21 to 23 (including workstations, bridges, routers, concentrators, etc.) can be directly connected to the dual ring 60. Numerals 31 to 3n are stations (workstations or the like), and are connected to the double ring 60 via the wiring device 1. Reference numerals 41, 421 to 423, and 431 to 43n are MAC layer control means for controlling communication and are included in each device to control the MAC layer. In the MAC layer control means,
It has packet format and address settings, and a cyclic redundancy check function. The concentrator device 1 is a device with low reliability when performing communication without connecting the MAC layer control means on the dual ring 60. That is, the normal distribution device 1 controls the MAC layer via the MAC layer control means, is connected to the dual ring 60, and performs communication. 71 to 7n are branch lines (spars), and the wiring device 1
1 and stations 31 to 3n are connected.

In FIG. 1, the wiring device 1, the communication control devices 21 to 23, and the stations 31 to 3n are physically connected, but not necessarily logically connected. The logically connected state means a state in which data can be transmitted and received according to a certain protocol. In the state of being logically connected, the MAC layer control means 4
1, 421 to 423 and 431 to 43n operate programs for performing MAC layer control, communication management and protocol control in order to transmit and receive data. Hereinafter, this program is called a control program. Each device has a MAC layer control means, and can transmit and receive data in a frame format through the operation ring 61 of the trunk line ring. That is, the MAC layer control means is a control means for controlling transmission / reception according to the control program.

A detailed description of each device will be given below.

FIG. 2 is a wiring device 1 in the state of FIG.
It is the figure which showed the internal structure. In FIG. 2, 511
Reference numerals 1-5112, 5121-512n are physical layer control means. The physical layer control means is a PMD (Phys
ical Media Dependent) and PHY (Physical Layer p)
rotocol) and have the functions specified in. 611 and 612 are the operational ring 61 of the double ring 60.
621 and 622 are connected to the double ring 60.
Of these, the line is connected to the standby system ring 62. The trunk rings 612 and 621 are called the A port side, and the trunk rings 611 and 622 are called the B port side. 71
1 to 7n1 are branch lines, which are from the distribution device 1 to the stations 31 to 3n
Transmission lines to the stations, 712 to 7n2 are branch lines, and stations 31 to 3n
Is a transmission line from the to the wiring device 1. 8111-811
2 and 8121 to 812n are transceivers, and support physical layer levels for transmission and reception. 91
1, 9121 to 9124, 91311 to 913n1, 9
Reference numerals 1312 to 913n2 denote selectors that switch between the normally closed side and the normally open side of the data path.
By switching this selector, it becomes a connection means for one-to-one connection with another node, or a disconnection means for disconnecting from another node. In the figure, switching of selectors is shown by a solid line and a dotted line of the data path.
That is, since the data path indicated by the solid line indicates the logical data path, the selector is switched to the side to which the solid data path is connected. In FIG. 2, all selectors are switched to the normally closed side. The data path indicated by the dotted line indicates that no logical connection is made. In FIG. 2, since the device connected to the wiring device 1 is operating normally in the state of this figure, the internal selectors 911 and 9121
~ 9124, 91311 ~ 913n1, 91312 ~ 9
All 13n2 are switched to the normally closed side. Therefore, the path shown by the broken line is physically connected, but is not used in the state shown in FIG. Reference numeral 101 denotes a node processor, which includes MAC layer control means 41 and physical layer control means 5111 to 5112 and 5121.
˜512n, communication control, protocol control, and selector switching instruction. 111 is an IPL (Initial Program Load) ROM of the node processor, and 121 is a control program storage area. The MAC layer control unit 41, the physical layer control units 5111 to 5112, 5121 to 512n, the control program storage area 121, the ROM 111, and the node processor 101 are connected by an internal bus.

In FIG. 2, the data input from the operation ring 612 of the trunk line is received by the transmitter / receiver 8111, and is connected to the MAC layer control means 41 by the selector 911 via the physical layer 5111. In the MAC layer control means 41, programs for performing control, communication management and protocol control operate. Further, the MAC layer control means 41 is connected to the physical layer 5111 by the selector 911, and is transmitted from the transmitter / receiver 812n to the station 3n through the spur 7n1 through the normally open sides of the selector 9122 and the selector 913n1. The data received by the station 3n is received by the transceiver 812n from the station 3n through the spar 7n2 and passes through the physical layer 512n.
At 11, it is returned to the physical layer 512n. Physical layer 512n
From selector 913n2 and selector 913 (n-
1) Transmitted from the transceiver to the next station through the normally open side of 1. Similarly, the data from each station is folded back at the physical layer and sent to the next station. Then, the data sent to the station 1 is looped back at the physical layer 5121, passed through the normally open sides of the selector 91312 and the selector 9124, and transmitted from the transceiver 8112 to the working ring 6
The data is transmitted from 11 to the next communication control device or wiring device. The data path from the backup system ring 622 is looped back at the physical layer 5112 and is connected to the backup system ring 621 via the transmitter / receiver 8111 through the normally open sides of the selector 9123 and the selector 9121.
As described above, data is normally transmitted / received via the working ring.

FIG. 3 is a diagram showing an internal configuration of the communication control device 23 in the state of FIG. In FIG. 3, 5
231 to 5232 are physical layer control means, 611 to 612 are lines connected to the active system 61 of the dual ring 60, 6
21 to 622 are lines connected to the backup system 62 of the dual ring 60, 8231 to 8232 are physical layers for transmission and reception, 9231 and 92321 to 92324 are selectors for switching data paths, and 1023 is MAC layer control means 42.
3, a node processor that controls the physical layer control means 5231 to 5232 to perform communication management and protocol control, 1123
Is an IPL ROM of the node processor, and 1223 is a control program storage area. 5231 to 5232 are physical layer control means, MAC layer control means 423, control program storage area 1223, ROM 1123, and node processor 1023 are connected to the internal bus.

Meanings of the solid line and the broken line in FIG. 3 are the same as those in FIG. 2, and the solid line indicates a logically connected data path, and the broken line is physically connected, but logically by the function of the selector. Indicates a data path that is not used.

In FIG. 3, the data input from the operation ring 612 of the trunk line is received by the transmitter / receiver 8231 and is connected to the MAC layer control means 423 and controlled by the selector 9231 via the physical layer 5231. .. Further, the MAC layer control means 423 is connected to the physical layer 5231 by the selector 9231, and is transmitted from the transceiver 8232 to another device through the operation ring 611 through the normally open side of the selector 92324. The data path from the backup system ring 622 is looped back at the physical layer 5232 and is connected to the backup system ring 621 through the transmitter / receiver 8231 through the normally open side of the selector 92321. As described above, data is normally transmitted / received via the working ring.

FIG. 4 is a diagram showing the internal configuration of the station 31 in the state of FIG. In FIG. 4, reference numeral 531 is a physical layer control means, 711 to 712 are branch lines connecting the wiring device 1 to the station, 831 is a physical layer for transmission and reception, and 1031 is MA.
A node processor that controls the C layer control means and the physical layer control means to perform communication management and protocol control, 1131 represents an IPL ROM of the node processor, and 1231 represents a control program storage area.

In FIG. 4, in the station, the data input from the spar 711 is received by the transmitter / receiver 831 and is connected to the MAC layer control means 423 via the physical layer 531 and controlled. Also, the station determines whether or not the destination address in the frame is the address addressed to itself, receives the frame addressed to itself, and sends other frames as they are. Further, the MAC layer control unit 431 is connected to the physical layer 531 and the transceiver 831 is connected.
The data is transmitted from the spar 712 to the wiring device.

1. Initial State Next, the initial state will be described.

In the network system of the present invention, not all the devices forming the network have the control program in the device, and the devices having the control program and the devices not having the control program are mixed on the network. There is. Devices that do not have a control program do not join the network when powered on.

This embodiment shows a case where such a device receives a control program from another device via the network in order to join the network. With another device, a communication control device adjacent to the device having a control program,
Refers to nodes such as stations and collectors. In order to achieve this, a device that does not have a control program
It has at least the following three functions in addition to the function as a device forming a network.

(I) A function of logically connecting to an adjacent device on a one-to-one basis. (Ii) A function of transmitting and receiving data using a simple protocol in the state of (i) above. (Iii) Received data The function to operate the computer as a control program.

Hereinafter, a program that a device that does not have a control program initially has to realize these three functions is called a transfer program. When the power is turned on, the node processor 101 determines whether or not it has a control program, and if it does not have it, it activates the transfer program. If you have a control program, start the control program. In the wiring device 1 shown in FIG. 2, the transfer program is stored in the ROM 111, and the node processor 101 operates the selectors 911, 9121 to 9124, and 91311 to 913 in accordance with the transfer program.
1n, 91321 to 9132n, MAC layer control means 41
Also, the physical layer control means 5111 to 5112 are controlled to receive the control program, which is loaded into the control program storage area 121 to be operated.

2. Initial load of control program via network and joining to ring A device that does not have a control program tries to receive a control program from a device having an adjacent control program immediately after power-on. Several cases are possible depending on which device requests the control program, and each will be described below.

(1) When the distribution device requests a control program to a station In FIG. 5, the distribution device 1 is connected to the branch line of the station 31.
FIG. 6 shows a network system in the case of receiving and executing the control program from FIG. 6, and FIG. 18 is a flowchart of the transfer program in the distribution device 1.

In FIG. 5, devices having the same functions as those shown in FIG. 1 are designated by the same reference numerals. However, the internal connection of the distribution device 1 is different from the connection shown in FIG.
Details of the internal connection are shown in FIG.

Hereinafter, the operation of the wiring device 1 from receiving the control program from the station 31 connected to the branch line to executing the control program will be described with reference to FIGS. 5, 6 and 18.

In FIG. 5, since the initial distribution device 1 does not have a control program, it cannot join the double ring 60. However, since the station 31 itself has the control program and does not know that the distribution device 1 does not have the control program, the same operation as that in the normal operation is made to the distribution device 1 through the branch line 712 in FIG. The protocol issues a request to join the dual ring 60. Upon receipt of the ring joining request, the distribution device 1 processes as in the flowchart of the transfer program shown in FIG. The transfer program is provided in advance in a storage means such as the control program area 121 or the ROM 111, and is processed by the node processor 101. Further, transmission / reception with each device is performed via the MAC layer control means 41.

As shown in FIG. 18, first, when a request for joining the dual ring 60 from the station 31 is received (process 180),
It is determined that the double ring 60 has been separated (process 182), and if it is not separated from the double ring 60, the double ring 60 is separated (process 18).
3). If it is disconnected, the station 31 is connected one-to-one and the other device is not connected (process 184). The separation method will be described later.

Next, the station 31 is requested to transmit the control program (process 185). Further, the station may inquire whether or not it has the control program, and if the station does not have the control program, it may be transferred from the station or the communication control device having another control program. Regarding the transmission request, it is possible to make a request with a protocol different from that in the normal operation or to make a response with the same protocol as in the normal operation. When connecting using different protocols, the connection itself can serve as a transmission request. This can be realized, for example, by transmitting a special combination of symbols that is not used in the connection protocol during normal operation. When the connection is made by the same protocol as in the normal operation, the control program is requested to be transmitted as in the normal transmission / reception. The request frame format is determined in advance.

The station 31 transmits the control program as data to the central wiring device 1 in response to a request from the central wiring device 1 (transfer means). When a connection is made with a protocol different from the protocol at the time of normal operation, the transmission method depends on that protocol. For example, it is possible to transmit asynchronously without adopting the frame format. Further, considering that the MAC layer control means is also used during the normal operation, the reliability can be improved by transmitting in the frame format. When the connection is established using the connection protocol during normal operation, the frame format determined in advance is used as in the case of issuing a request.

Next, the distribution center 1 receives the control program from the station 31 (reception means) (process 186), and after the reception is completed, the distribution center 1 temporarily disconnects the logical connection with the station 31. (Process 187). Station 31 when disconnected
By the action of the control program, the request for joining to the dual ring 60 is issued again to the distribution device 1. On the other hand, the distribution device 1 stores the received control program in the control program storage area 121 (process 188) and then activates the control program (process 189). Then, the dual ring 60 is rejoined to start normal operation, and then the station 3
A request for joining the dual ring 60 of 1 is accepted.

In this way, the distribution device 1 loads the control program from the station 31 and joins the network system.

The above-mentioned one-to-one connection and ring disconnection method will be described below.

As described above, the collecting and wiring device 1 and the station 31 are connected to each other in a one-to-one manner, and the dual ring 60 is logically separated from each other. The communication control devices 21 and 23 are set so that they cannot communicate with each other. This is because the selector 911 in FIG. 6 is replaced by the MAC layer control means 41 and the physical layer control means 5.
121 and selector 9
This can be realized by folding back the double ring by connecting 1311 and 91312 in the reverse connection to the normal state. That is, in FIG. 6, the data path from the station 31 is the branch line 7
The physical layer 5 is received by the transceiver 8121 through
The selector 911 is connected to the MAC layer control means 41 via 121. Furthermore, from the MAC layer control means 41, through the physical layer 5121, through the normally open side of the selector 91311, it is transmitted from the transceiver 8121 and is connected to the station 31. This allows a one-to-one connection. Also, on the dual ring side, the data input from the active ring 612 corresponds to the transmitter / receiver 8111.
Is received by the selector 91 via the physical layer 5111.
1, and the transmitter / receiver 81 passes through the physical layer 5111 and the normally open side of the selector 9121.
11 is sent to the standby system ring 621. On the other side, the data from the standby ring 622 is received by the transmitter / receiver 8112, and the selector 911 is received via the physical layer 5112.
And returned to the selector 9 via the physical layer 5112.
Through the normally open side of 124, the transmitter / receiver 811
2 is sent to the working ring 611. This allows
The signals coming from the communication control devices 21 and 23 can be put into the through state without being processed or monitored in the distribution device 1, and can be sent back by using the working ring and the spare system 62 together. It is possible to disconnect from other nodes that do not transmit or receive. In FIG. 6, the wiring device 1 is
Since there is only one C-layer control means 41, the concentrator / wiring device 1 can be logically configured as a dual ring 60 only by doing this.
Can be separated from.

As another example, without returning the double ring, the MAC layer control means is not connected on the double ring, and the rest are connected to the normal data path to perform communication, and the continuous wiring device 1 is connected. Then, a Q symbol is output. As a result, the communication control devices 21 and 23 can be forcibly placed in the wrapping state, and the wiring device 1 can be disconnected.

(2) When the distribution device requests a control program to the communication control device: The distribution device 1 is connected from the communication control device 23 having only one MAC layer control means 423 adjacent on the double ring. FIG. 7 shows a network system in the case of receiving and executing the control program, and FIG. 8 shows a connection state inside the wiring device 1 at that time. Further, FIG. 9 shows a connection state inside the communication control device 23. In addition, a flow chart of the transfer program in the distribution device 1 is shown in FIG.
FIG. 20 shows a flowchart of the transfer program in.

In FIGS. 8 and 9, the main ring 612,
It is assumed that the 621 side (A port side) is connected to the wiring device 1.

The part different from (1) in the case where the distribution device 1 requests a control program from the communication control device 23 is as follows.
There are the following two points.

(I) The centralized wiring device 1 is not a device that receives a connection request, but a device that issues a connection request. (Ii) A device that issues a request for the centralized wiring device 1 to transmit a control program. , Not the station 31 but the communication control device 2
That is 3.

Hereinafter, the operations from the centralizing and wiring apparatus 1 sending a connection request to the communication control apparatus 23, and the centralizing and wiring apparatus 1 receiving and executing the control program from the communication control apparatus 23 will be described with reference to FIGS. This will be described with reference to FIGS.

In FIG. 7, since the initial distribution device 1 does not have a control program, it cannot join the double ring 60. Therefore, first, the wiring device 1 requests the communication control device 23 to transfer the control program. FIG. 19 shows a flowchart of the transfer program at that time. The transfer program is provided in advance in a storage unit such as the control program area 121 or the ROM 111 in FIG. 8 and processed by the node processor 101. In addition, the communication control device 23 uses the wiring device 1
FIG. 20 shows a flow chart of the transfer program when the control program transfer request is received and transmitted.

As shown in FIG. 19, first, the wiring device 1
Judges that it is in a state of being separated from the double ring 60 (process 191), and if it is not separated from the double ring 60, disconnects the double ring 60 (process 1).
92). If separated, the communication control device 23 is connected one-to-one and the other devices are not connected (process 19).
3). The separation method will be described later.

Next, the communication control device 23 is requested to transmit the control program (process 194). Regarding the transmission request, it is possible to make a request with a protocol different from that in the normal operation or to make a response with the same protocol as that in the normal operation. When responding with the same protocol, the distribution center 1 and the communication control device 23 are connected by a normal FDDI protocol, and the distribution center 1 is connected to the double ring 60.
Since you are going to subscribe to, make a one-to-one connection and send a request. The request frame format is determined in advance. In the case of making a request using a different protocol, there is no possibility of joining the double ring 60 as it is, and therefore the joining request itself can be used as the transmission request of the control program. Any method may be used for transmitting the program regardless of the communication method using the frame.

Next, as shown in FIG. 20, the communication control device 23 that has received the transmission request (process 200) determines that the communication control device 23 is disconnected from the duplex ring 60 (process 201), and If it is not separated from the heavy ring 60, the double ring 60 is separated (process 202) and a one-to-one connection with the current collector 1 is performed (process 203). The protocol is determined from the transmission request from the wiring device 1 and the control program is transferred using the same protocol (Process 2).
04). When the protocol is determined in advance, the transfer may be performed according to the determined protocol without determining the protocol. After the transfer is completed, when the line to the distribution device 1 is disconnected (process 205), the communication control device 23 joins the dual ring 60 (process 206).

On the other hand, in the wiring device 1, the communication control device 2
3 receives the control program (process 195), and after the reception is completed, the wiring device 1 disconnects the logical connection with the communication control device 23 (process 196). The central wiring device 1 stores the received control program in the control program storage area 121.
After that, the control program is activated (process 198). And double ring 60
Join again to start normal operation.

In this way, the distribution device 1 loads the control program from the communication control device 23, and again issues a request for joining the dual ring 60 to the communication control device 23. In response to this, the communication control device 23 performs a joining process to the dual ring 60.

The above-mentioned one-to-one connection and ring disconnection method will be described below.

As described above, the wiring device 1 and the communication control device 23 are connected in a one-to-one manner and are logically separated from the double ring 60, and the communication control device 2 in FIG.
The double rings are folded back so that they cannot communicate with each other. This is done by switching the selector 911 inside the collector / wiring device 1 in FIG. 8 so that the MAC layer control means 41 and the physical layer control means 5121 are connected, and the selectors 9124, 9123, 9122 and 9121 are in the normal state. This can be achieved by making the reverse connection to. That is, in FIG. 8, the data path with the communication control device 23 is received by the transmitter / receiver 8111 via the active ring 612, and is connected to the MAC layer control means 41 by the selector 911 via the physical layer 5111. In addition, MAC
From the layer control means 41, through the physical layer 5111, through the normally open side of the selector 9121, the transceiver 8
It is transmitted from 111 and is connected to the communication control device 23 through the standby ring 621. In addition, the B port side connected to the other communication control device 21 has a standby system ring 622.
The data from is received by the transmitter / receiver 8112 and returned by the selector 911 via the physical layer 5112.
The signal is sent from the transceiver 8112 to the working ring 611 through the physical layer 5112 and the normally open side of the selector 9124. As a result, the signals coming from the communication control devices 21 and 22 can be put into the through state without being processed or monitored in the collector / wiring device 1, and the working ring and the backup system 62 can be sent back together. Wiring device 1
And the communication control device 23 can be logically connected one-to-one.

Further, in FIG. 9, the data path in the communication control device 23 is received by the transmitter / receiver 8232 through the standby ring 622, and is connected to the MAC layer control means 423 by the selector 9231 via the physical layer 5232. To be done. Further, from the MAC layer control means 423, the physical layer 52
The signal is transmitted from the transmitter / receiver 8232 via the normally open side of the selector 92324 via 32, and is connected to the wiring device 1 via the operation system ring 611.
Also, the A port side connected to the other communication control device 22 is
The data from the operational ring 612 is transmitted and received by the transceiver 8231.
Received by the selector 92 via the physical layer 5231.
Then, the data is sent back to the standby system ring 621 from the transceiver 8231 through the normally open side of the selector 92321 via the physical layer 5231. As described above, the wiring device 1 and the communication control device 23 can be logically connected one-to-one by disconnecting from the double ring 60.

By taking such a procedure, it is possible to prevent a device having no control program from joining the double ring 60.

Each device can also have two or more MAC layer control means. Below, a communication control device having two MAC layer control means will be described as an example. 10 and 1
A communication control device 23 having two MAC layer control means 4231 and 4232 as shown in FIG. 1 and FIG. 12 will be described.

FIG. 1 shows a network system in the case where an adjacent wiring device 1 receives a control program from a communication control device 23 having two MAC layer control means and executes the control program.
0, two MAC layer control means 4231 and 42
11 shows a normal internal configuration of the communication control device 23 having 32.
12 shows a connection state inside the communication control device 23 when the control program is transferred to the distribution device 1.

First, the operation when joining the dual ring and performing normal communication will be described with reference to FIG.

In FIG. 11, the data path in the communication control device 23 is the transmitter / receiver 82 through the active ring 612.
31 and is connected to the MAC layer control means 4231 via the physical layer 5231. Further, from the MAC layer control means 4231, through the physical layer 5231, through the normally open side of the selector 9232, the transceiver 82
It is transmitted from 32 and is connected to the adjacent wiring device 1 through the operation system ring 611. Further, the standby system ring 622 is received by the transceiver 8232, and the physical layer 5
It is connected to the MAC layer control means 4232 via 232. Furthermore, from the MAC layer control means 4232, the physical layer 5
The spare ring 621 from the transmitter / receiver 8231 through the normally open side of the selector 9231 via 232.
Sent to. Normally, the spare ring does not have to be used, but when a failure occurs in the working ring, it can be switched to the spare ring. A MAC that connects to the working ring by having two MAC layer control means
In the layer control unit 4231, even when a failure occurs, it can be dealt with by switching to the standby system.

FIG. 12 shows the connection state inside the communication control device 23 when the control program is transferred to the distribution device 1.
Will be explained.

In FIG. 12, the data path in the communication control device 23 includes a transmitter / receiver 82 through a standby system ring 622.
32, and is connected to the MAC layer control means 4232 via the physical layer 5232. Further, from the MAC layer control means 4232, through the physical layer 5232, through the normally open side of the selector 9232, the transceiver 82
It is transmitted from 32 and is connected to the wiring device 1 through the operation system ring 611. In addition, another communication control device 2
The data from the working ring 612 is received by the transmitter / receiver 8231 on the A port side connected to the physical layer 52.
It is connected to the MAC layer control means 4231 via 31. Furthermore, from the MAC layer control means 4231, the physical layer 5
231 via the normally open side of the selector 9231 and the standby ring 621 from the transmitter / receiver 8231.
Sent to. As described above, the wiring device 1 and the communication control device 23 can be logically connected one-to-one while joining the double ring 60. That is, the communication control device 23 itself can transfer the control program to the distribution device 1 while communicating with another device connected to the dual ring 60.

(3) When the station requests the control program to the central wiring device: The central wiring device 1 having only one MAC layer control means 41 joins the double ring 60, and its branch line 7n. FIG. 13 shows a network system in the case where the station 3n connected to the station 3n has not yet joined the dual ring 60 and the station 3n loads the control program from the distribution center 1 via the branch line 7n. FIG. 14 shows a connection state of the inside of the wiring device 1.

Although not shown in the figure, the internal configuration of the station 3n is M in the internal configuration diagram of the station 31 shown in FIG.
AC layer control unit 431, physical layer control unit 531, branch lines 711 and 712 to the wiring device, physical layer 831 for communication, node processor 1031, IPL ROM1
131 and control program storage area 1231 are numbered 43n, 53n, 7n1, 7n2, 83n, and 103, respectively.
It has been changed to n, 113n, and 123n.

When the station 3n requests the control program from the distribution device 1, the points different from (1) and (2) are the following two points.

(I) The device that issues a connection request is a station, not a distribution device. (Ii) The distribution device 1 is a device that transmits a control program, not a device.

Hereinafter, the station 3n connected to the branch line
However, the operation from receiving and executing the control program from the distribution device 1 will be described with reference to FIGS. 13, 14 and 21.

In FIG. 13, the first wiring device 1 joins the double ring 60 to perform communication. Station 3n
Since it does not have a control program, it issues a request to join the dual ring 60 to the distribution device 1 through the branch line 7n. When the wiring device 1 receives a request for ring joining,
Processing is performed as in the flowchart of the transfer program shown in FIG.

As shown in FIG. 21, first, the wiring device 1
When receiving a request for joining the dual ring 60 from the station 3n (process 210), the station determines whether the station has a control program (process 211). Regarding the method of requesting the station 3n to join, it is possible to make a request using a protocol different from that during normal operation, or to make a request using the same protocol as during normal operation. When connecting using a different protocol, it can be seen that the station 3n does not have a control program because of the connection, and therefore it can also serve as a transmission request. This can be realized, for example, by transmitting a special combination of symbols that is not used in the connection protocol during normal operation. When the connection is made by the same protocol as in the normal operation, the control program is requested to be transmitted as in the normal transmission / reception. The request frame format is determined in advance. Alternatively, the control program may be forcibly sent without making an inquiry, and when the control program exists on the station side, the central wiring device 1 may be notified that transmission is not required.

Next, if the station n has a control program, the station n is added to the dual ring 60 as it is (process 2).
16). If there is no other station, the other distribution station remains joined to the trunk ring, and the distribution device 1 is disconnected from the trunk ring (process 212) to establish a one-to-one connection with the station 3n (process 2).
13). The separation method will be described later. Next, station 3
The control program is transmitted to n (process 21).
4). After the transmission is completed, the central wiring device 1 temporarily disconnects the logical connection with the station 3n (process 21).
5). When disconnected, the station 3n stores the received control program in the control program storage area 123n, activates the control program, and issues a request to join the double ring 60 again to the distribution center 1. And the wiring device 1
Joins the station 3n and the wiring device to the dual ring 60 and starts normal operation (process 216).

In this way, the station 3n can load the control program from the wiring device 1 and join the network system.

The above-mentioned one-to-one connection and ring disconnection method will be described below.

As described above, the wiring device 1 and the station 3n are connected to each other in a one-to-one manner and are logically separated from the double ring 60, and the adjacent communication control device 2 in FIG.
It is set so that they cannot communicate with each other. This is because the selector 911 in FIG. 14 is switched so that the MAC layer control means 41 and the physical layer control means 512n are connected, and the selectors 9121 to 9124 and 913 are connected.
This can be realized by switching n1 and 913n2 as shown in FIG. That is, in FIG.
The data path from the transmitter / receiver 81 through the branch line 7n2
2n, and the selector 911 connects to the MAC layer control means 41 via the physical layer 512n. Further, from the MAC layer control means 41, through the physical layer 512n, through the normally open side of the selector 913n1, is transmitted from the transceiver 812n, and is connected to the station 3n.

On the double ring side, the working ring 61
The data input from No. 2 is received by the transmitter / receiver 8111, returned by the selector 911 via the physical layer 5111, and passed through the normally open side of the selector 9122 via the physical layer 5111 to the station 3 (n-1). ) Is connected to. In this way, through all the connected stations, from the station 1 through the physical layer 5121, through the normally open side of the selector 9124 and the selector 91312,
It is transmitted from the transceiver 8112 to the operational ring 611. As a result, the communication control device 21,
It is possible to put the MAC layer control means 41 of the concentrator / wiring device in a through state to the station and disconnect it from the trunk ring without processing or monitoring the normal transmission data coming from 23 to make a one-to-one connection with the station n.

Further, as described above, each device can have two or more MAC layer control means. The following describes a wiring device having two MAC layer control means. Two MACs, as shown in FIGS. 15, 16 and 17.
The wiring device 1 having the layer control means 412 and 411 will be described.

The concentrator 1 having the two MAC layer control means 411, 412 has joined the dual ring 60, and the station 3n connected to its branch line 7n has not joined the dual ring 60 yet. FIG. 15 shows a network system in the case where the station 3n loads the control program from the distribution device 1 via the branch line 7n, and shows a normal internal configuration of the distribution device 1 having two MAC layer control means 411 and 412. FIG. 16 shows the configuration, and FIG. 17 shows the internal connection state of the wiring device 1 when the control program is transferred.

First, the operation when joining the dual ring and performing normal communication will be described with reference to FIG.

In FIG. 16, the data path in the wiring device 1 is connected to the transmitter / receiver 81 through the working ring 612.
11 and is connected to the MAC layer control means 411 by the selector 9111 via the physical layer 5111.
Further, from the MAC layer control means 411, the physical layer 5111
Via the normally open side of the selector 9122 and the selector 913n1 and is transmitted from the transceiver 812n to be connected to the station n. Similarly, through each station,
From the station 1 through the physical layer 5121, through the normally open sides of the selector 9124 and the selector 91312,
It is sent from the transceiver 8112 to the operational ring 611. In addition, the standby system ring 622 includes a transceiver 8112.
Is received by the selector 91 via the physical layer 5112.
11, the physical layer 5112 and the selector 91 are returned.
23 and the normally open side of the selector 9121, and the signal is sent from the transceiver 8111 to the standby system ring 621. Further, the MAC layer control means 412 is provided in the standby ring.
May be connected. Normally, it is not necessary to use the backup ring, but when a failure occurs in the working ring,
It is possible to switch to the spare ring. By having two MAC layer control means, even if a failure occurs in the MAC layer control means 411 connected to the working ring, it can be dealt with by switching to the standby system.

The internal connection state when the distribution device 1 transfers the control program to the station n will be described with reference to FIG.

In FIG. 17, the data path from the station 3n is received by the transmitter / receiver 812n via the branch line 7n2, and is transmitted to the selector 9112 via the physical layer 512n.
It is connected to the AC layer control means 412. Further, from the MAC layer control means 412, through the physical layer 512n, through the normally open side of the selector 913n1, it is transmitted from the transceiver 812n and is connected to the station 3n. Also, on the dual ring side, the data input from the active ring 612 is received by the transmitter / receiver 8111, and the physical layer 51
The selector 9111 is connected to the MAC layer control means 412 via 11. Further, the MAC layer control means 4
12 from the selector 9122 via the physical layer 5111.
Is connected to the station 3 (n-1) through the normally open side. In this way, the selector 912 is transmitted from the station 1 through the physical layer 5121 through all the connected stations.
4 and the selector 91312 through the normally open side, and the signal is transmitted from the transceiver 8112 to the working ring 611.

As described above, it is possible to make a one-to-one connection with the station n while the inside of the distribution device 1 joins the double ring. That is, the control wiring program 1 can transfer the control program to the station n while communicating with another device connected to the double ring 60.

3. Replacement of Control Program via Network Next, a method of replacing the control program of the device connected to the network via the network will be described with reference to FIG. The replacement of the control program occurs when the version of the control program is upgraded.

When the network system shown in FIG. 1 starts to operate, when there is a device having a control program at the stage of power-on in the network, the control of each device is performed. The program version may be different. Even in such cases, if there is only a small difference, the system may start operating. To prevent this,
A device in the network sends a frame inquiring all the devices on the dual ring 60 for the version of the control program to check whether the versions match. In the case of FDDI, SMT (Station Ma
nagement) By looking at the ID field in the information section of the frame format, it is possible to know whether the versions match. Since the NIF class SMT frame used to create the station map in the ring must be transmitted once every approximately 30 seconds, this is used to know the version of the control program of all devices on the ring. be able to. As a result, if the control program versions do not match, the control programs are replaced.

When the control program is upgraded, the control programs of all the devices connected to the network must be replaced. In this case, the control program may be held as data in any one of the devices connected to the network, the control program may be distributed to the entire network, and then the new control program may be switched to.

Here, when the network system shown in FIG. 1 is operating normally, it is necessary to replace the control program of the device connected to this network system with the control program of the station 31. Take for example. At this time, first, the station 31 issues a notification to newly transmit the control program to a device that needs to replace the control program among the devices connected to the network in the normal communication state. Next, the station 31 transmits the control program to all the target devices. After confirming that the control program has been transmitted, the station 31 notifies the target device to switch to the new one that transmitted the control program. Here, the notification of the control program transmission, the transmission of the control program, and the notification of the control program switching are performed using a predetermined frame format. Any frame format may be used. Then, in accordance with this notification, each device loads a new control program in the control program storage area and then restarts the new control program.

Further, a method of matching the versions of the control programs without stopping the entire network system will be described below. For example, a case where it becomes necessary to replace the new control program owned by the station 31 with all the devices of the network will be taken as an example. In this case, similarly to the case where the distribution device in 2 (1) requests the control program to the station, the distribution device 1 and the station 31 are connected one-to-one to transfer the control program. That is, the station 31 informs the centralizing device 1 of a version upgrade of the control program, and the centralizing device 1 is set in a mode of disconnecting from the trunk ring to establish a one-to-one connection with the station 31 and transfer the control program. After the transfer, this time, the wiring device 1 notifies the communication control device 23 of the version upgrade of the control program, and transfers the control program in a one-to-one connection. After the transfer is completed, the communication control device 23 similarly transfers to the next communication control device. Similarly, transfer is performed to an adjacent device. After the transfer, the distribution device 1 and the communication control device 23 activate the control program after the version upgrade to newly configure the trunk ring, and thereafter, the upgraded devices are sequentially added to the trunk ring. Go In this way, the control program of the new version and the control program of the old version are mixed by configuring the trunk ring newly with only the upgraded device after transferring after connecting one-to-one with the adjacent device. It is possible not to do so, and the version can be upgraded without stopping the entire network. Further, regarding the version upgrade of other stations connected to the distribution center 1, the distribution center 1 transfers the stations for each station before the distribution system 1 activates the control program after the version upgrade, or , Can be transferred to all stations at the same time.

Further, when the above-mentioned two MAC layer control means are provided, it is possible to make a one-to-one connection without disconnecting the trunk ring, and it is possible to upgrade the version without affecting other stations during transfer.

4. Method of Saving Control Program For a device connected to the network, each time the power is turned on, the control program may be loaded from the other device on the network to the control program storage area by the method described in the previous section. In this case, the number of devices having the control program is limited, so that the control program can be stored and managed easily.

Further, if each device connected to the network has a storage means having a small volume and which can be easily updated, and a control program is stored in the storage means, it is possible to perform initial loading or program replacement. Except for the above, the control program can be loaded from the storage means into the main memory and started up. The following may be considered as an example of such storage means.

(I) Static RAM (S-RAM)
Even if the power of the main unit is turned off, S-
Storage means for backing up data in RAM so as not to be erased. (Ii) Electrically erasable programmable ROM (E
EP-ROM), a circuit for erasing and writing the EP-ROM, and a storage unit that combines the control program (iii) A device that combines the nonvolatile RAM and the control circuit.

The non-volatile RAM (iii) is a device in which an electrically erasable programmable ROM (EEP-ROM) and a normal static RAM (S-RAM) are combined, and is between the EEP-ROM and the S-RAM. Data transfer is automatically performed by a control signal from outside the device. When the power is turned on, S from EEP-ROM
-Transfer the data to RAM, and normal data access is S
-Perform on RAM. Then, when the power is turned off, the data is stored from the S-RAM to the EEP-ROM.
Therefore, unlike the S-RAM of (i), a power source for backup is not required, and a complicated erasing / writing circuit of the EEP-ROM and a control program as in (ii) are not required. Data can be stored.

[0095]

According to the present invention, the devices constituting the network only need to load the control program from another device via the network, so that it is not necessary for all the devices to have the control program. At the time of initial loading of the control program, the target device does not logically join the trunk line and is connected one-to-one, so that the control program can be transmitted and received without degrading the reliability of the trunk ring. Since each device only needs to have a ROM that stores a simple procedure until the control program is loaded and activated, the device housing can be downsized. By doing so, the control program can be collectively stored and managed in a limited place on the network, and the replacement of the program can be simplified.

Further, by storing the control program in a small-sized storage device which can be easily updated, the control program can be stored in the storage device without increasing the size of each device housing and making the replacement of the program difficult. It can be built into the housing.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing a standard configuration example of a ring LAN system.

FIG. 2 is an explanatory diagram showing the internal configuration of the wiring device 1 at the time of FIG.

FIG. 3 is an explanatory diagram showing the internal configuration of the communication control device 23 at the time of FIG. 1;

FIG. 4 is an explanatory diagram showing the internal configuration of the station 31 at the time of FIG.

FIG. 5 is a system configuration diagram showing logical connections when the distribution device 1 loads a control program from the station 31.

6 is an explanatory diagram showing logical connections inside the wiring collector 1 at the time of FIG. 5;

FIG. 7 is a system configuration diagram showing logical connections when the distribution device 1 loads a control program from the communication control device 23.

8 is an explanatory diagram showing logical connections inside the wiring collector 1 at the time of FIG. 7. FIG.

9 is an explanatory diagram showing logical connections inside the communication control device 23 at the time of FIG. 7. FIG.

10 is an explanatory diagram showing a logical connection when the distribution device 1 loads a control program from the communication control device 23. FIG.

FIG. 11 is a communication control device 2 having two MAC layer control means.
Explanatory drawing which shows the structure of 3 inside.

12 is an explanatory diagram showing a logical connection inside the communication control device 23 at the time of FIG.

FIG. 13 is a system configuration diagram showing a logical connection when the station 3n loads a control program from the wiring device 1.

14 is an explanatory diagram showing logical connections inside the wiring collector 1 at the time of FIG. 13. FIG.

FIG. 15 is an explanatory diagram showing a logical connection when the station 3n loads a control program from the wiring device 1.

FIG. 16 is an explanatory diagram showing an internal configuration of a wiring concentrator 1 having two MAC layer control means.

17 is an explanatory diagram showing logical connections inside the wiring device 1 at the time of FIG. 15. FIG.

FIG. 18 is a flowchart of a transfer program in the wiring device 1.

FIG. 19 is a flowchart of a transfer program in the wiring device 1.

FIG. 20 is a flowchart of a transfer program in the communication control device.

FIG. 21 is a flowchart of a transfer program in the wiring device 1.

[Explanation of symbols]

1 ... Wiring device, 21-23 ... Communication control device, 31-3
n ... station, 41.411-412.421-423.42
31-4232, 431-43n ... MAC layer control means,
5111-5112, 5121-512n, 5231-
5232/531 ... Physical layer control means 60 ... Double ring,
61.161 to 612 ... Primary ring, 62.6
21-622 ... Secondary ring, 71-7n.71
1-7n1, 712-7n2 ... Wiring device 1 and station 31-
Branch line (spar) connecting 3n, 8111 to 8112
8121 to 812n, 8231 to 8232, 831 ... Physical layer for transmission / reception, 911.9111 to 9112.9
121-9124, 91311-913n1, 9131
2 to 913n2, 9231 to 9232, 92321 to 9
2324 ... Selector for switching data path, 10
1, 1023, 1031 ... node processor, 111.
1123 ・ 1311 ... IPL for node processor
ROM, 121/1223/1231 ... Control program storage area.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Hirata, Inventor Kenji Hirata, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Microelectronics Equipment Development Laboratory (72) Inventor Toshihiko Ogura Totsuka-ku, Yokohama-shi, Kanagawa 292 Yoshida-cho, Hitachi, Ltd. Microelectronics equipment development laboratory (72) Inventor Naoya Ikeda 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Microelectronics equipment development laboratory (72) Inventor Hiromichi Enomoto 1 Horiyamashita, Hadano City, Kanagawa Prefecture Kanagawa Factory, Hiritsu Manufacturing Co., Ltd.

Claims (11)

[Claims] 1. A network having at least two nodes for controlling communication and a transmission line connecting the nodes.
In the communication system, the above-mentioned node has a disconnecting means for logically disconnecting the connection with the node not transmitting / receiving the control program when transferring the control program for controlling communication, and the node transmitting / receiving the control program. A node having a control program among the above-mentioned nodes has a transfer means for transferring the control program to another node, and a node receiving the control program is transferred. A network system having a receiving means for receiving the control program. 2. The network system according to claim 1, wherein the transmission lines are duplicated, and the disconnecting means separates the duplicated transmission lines by folding them back. 3. The node according to claim 1 or 2,
Alternatively, the network is characterized by being at least one of a concentrator device that accommodates two or more stations, a communication control device that controls communication, and a station that is connected to the concentrator device through a branch line of a transmission path. System. 4. The node according to claim 1, 2 or 3, further comprising means for confirming that the versions of the control programs match, and if the versions of the control programs do not match, the control program is transferred to match. The network system is characterized in that it is not transferred if it does. 5. The node according to claim 1, 2, 3 or 4, wherein the node further has a rewritable storage means in which the stored contents are not erased even when the power is turned off, and the storage means is a reception means A network system characterized by storing the control program received in. 6. The method according to claim 1, 2, 3, 4 or 5.
The network system, wherein the node further has one or more control means for controlling transmission / reception according to a control program. 7. The network according to claim 6, wherein the node joins the network by releasing the disconnecting means and the connecting means for making a one-to-one connection after executing the control program. System. 8. A network having at least two nodes for controlling communication and a transmission line connecting the nodes.
In the communication system, when transferring the control program for controlling communication to another node, the above node logically disconnects the connection with the node that does not transfer and makes a one-to-one connection with the transfer destination node. Control program transfer method, after which the one-to-one connection is terminated, the control program is started, the disconnection is released, and the network is joined. 9. The node according to claim 8, characterized in that, before transferring the control program, the node judges whether the versions of the control program match or not, and if the versions do not match, executes the transfer of the control program. Control program transfer method. 10. A transmission line having at least one of a concentrating device for accommodating one or more stations and controlling communication and a communication control device for controlling communication connected and duplexed. In the network system, the wiring device returns normal transmission data when transmitting and receiving a control program for controlling communication,
Make a one-to-one connection with the destination of the control program, send and receive the control program, and after finishing, start the control program, finish the one-to-one connection, release the disconnection, and join the network. Characteristic control program transfer method. 11. In two or more wiring devices for accommodating one or more stations and controlling communication, a node which is not transmitting and receiving a control program at the time of transferring a control program for controlling communication. And a connection means for making a one-to-one connection with a node transmitting and receiving a control program, and the node having the control program among the above-mentioned nodes A wiring device, comprising: transfer means for transferring to a node; and a node for receiving a control program, having receiving means for receiving the transferred control program.