JPS5991757A - Loop transmitter - Google Patents

Abstract

PURPOSE:To attain smooth rising without providing a transmitter for monitoring control by producing a token after a specific delay time of each device when a transmission line is failed in plural transmitters connected by double loop transmission lines in inverse direction each other. CONSTITUTION:Plural transmitters 10 are connected by transmission lines 11, 12 where the direction of transmission is opposite each other. When all the devices 10 are at the initial state after the application of power supply, whether or not the start request of the transmission start exists is checked, and when a device having a request depresses a start switch, the device is used as a master and a token is produced. If there exists a failure in the transmission line and the token is relinquished, the device elapsed by a delay time specific to each device 10 produces the token and is used as a master, the state of the other transmitter and the transmission line is checked, and information representing the state of the transmission line being operationable is transmitted, the reflecting transmission is performed by using the line 12 and a failed part 14 is disconnected. When the data transmission informing the data informed to the other transmitter is finished in the device 10, the token is transferred to the next device 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a transmission device that has a loop-shaped transmission path and controls data transmitted and received via the transmission path.

[Technical background of the invention]

In a system where a transmission path is configured in a loop and multiple transmission devices are connected to it, if each transmission device sends data to the transmission path at will, this data will cause interference on the transmission path. The transmission rights must be controlled by some means.

There are several i-methods for this, but the transmission device according to the present invention uses the conventionally known token delivery method.
n passing ) method is adopted. In this method, there is only one transmission right called a token in the system,
Only the transmission device that holds this information can transmit it. A transmission device that holds a token is only allowed to receive transmitted data from a transmission device that has the token.

However, how to generate just seven tokens in the system and how to transfer them between transmission devices is not generally established.

In the conventional device, a special transmission device for monitoring and control is provided in the transmission path, and this device generates tokens and controls sending and receiving the tokens to and from each transmission device.

[Problems with background technology]

However, if there is an abnormality in this device or the transmission line connected to it, the system will stop, so a backup device is essential, and control between these devices becomes complicated.

In addition, if there is a failure in the transmission equipment, the system that disconnected it,
The monitoring device also performs control to incorporate the system into the transmission system after the fault has been recovered, but the distance between the faulty device and the monitoring device often causes operational inconvenience.

As described above, a transmission system in which transmission control is performed at one location has problems in system reliability and operational operability.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a loop transmission device that overcomes the drawbacks of conventional devices.

[Summary of the invention]

The present invention connects a plurality of transmission devices with a double loop-shaped transmission path with the transmission directions opposite to each other, and controls the transmission so that the transmission right is established by receiving a token that exists only once in the system. In a transmission device, when all the transmission devices are in the initial state such as after the power is turned on, it is possible to start transmission from any transmission device, and if there is an abnormality in the transmission path, each transmission device can start the transmission. This is a loop transmission device that generates a token after a unique delay time, and the transmission device that generated the torque check the status of other transmission devices and the transmission line and generates information indicating the status of the operable transmission line. This is a loop transmission device that notifies all of the transmission devices capable of transmitting the same data via seven or λ loop-shaped transmission paths by circular transmission.

[Embodiments of the invention]

An embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 7 is a system configuration diagram using the loop transmission device in this embodiment. The transmission device 10 is connected by transmission lines called an R line and an L line whose data transmission directions are opposite to each other, and has a double loop structure. Normally, transmission is performed using the R line horn, and when an error occurs in the transmission device 10, the L line/2 is used for loopback transmission, and the abnormality part 1 is disconnected. Let's do it.

The transmission devices according to the present invention each have completely equivalent functions. This is a token transfer method established by the transmitter receiving a token, which exists only once in the system. When the transmission device 10 holding the o token completes the transmission of data to be notified to other transmission devices 10, R
Transfer the token to the next transmission device 10 via the line horn.Here, the former device will be referred to as the upstream station, and the latter device will be referred to as the downstream station.

Also, the transmission device that holds the token is called a mask, and the other devices are called slaves.

Therefore, there is no device specially provided for controlling the transmission.lx□ The transmission device 10 that receives the token immediately hands over the token to the downstream station when there is no data to be transmitted. If all transmitters do not have data to transmit, only the tokens will circulate through the transmission path.

The transmission format is data transmission between specific transmission devices:
Both transmission and broadcast transmission in which all slave transmission devices receive data transmitted from a mask transmission device are possible. These identifications are performed in the third @ minute SA of the transmission frame 13, which will be described later.

In n-e-n transmission, the slave transmission device 10 takes an acknowledgment that it has correctly received the data.On the other hand, in broadcast transmission, no acknowledgment is taken from each slave device. When the transmitted data returns via all the slave devices, the mask device compares the received data with the transmitted data, and if they match, it considers the data to have been correctly transmitted.

FIG. 7(b) shows the transmission form when the transmission line fails.

Since the transmission path has a double loop configuration, the transmission devices 10 (STNi and 5TNi+) at both ends of the failure point 13
1) shows an example in which data received on R line// and L line/2 is transmitted to the opposite line.

FIG. 2 is a diagram showing the format of data flowing through a transmission path. With reference to this diagram, the format of data passed between transmission devices 70 will be explained. It has been established.

The first part is the command CMD. This is to identify the contents of transmission frame/3, and is a test (TES)
T), line configuration (CN-F), text (TEXTO)
, retransmission text (TEXT/), token (TOKEN
), an acknowledgment (ACK), or a negative acknowledgment (NAK).0 The second part SA is for specifying the transmission device that should receive the transmission frame, and this value is II □
Only when N is the transmission frame that all transmission devices receive, that is, broadcast transmission.

The third part PA represents the address of the transmitter of the mask transmitting the transmission frame.

The ≠-th part N specifies the data length of the text portion TEXT that follows.

The text part TEXT of the jth part is where information to be transmitted from the master to the system slave is entered.

The final check section BCC is provided to detect bit errors in the transmission frame.

FIG. 3 is a diagram showing the internal structure of the transmission device according to the present invention.

The flow of transmission data within the seven transmission devices io will be explained with reference to FIG.

First, the operation when the device is in the slave state and the contents of the second portion CMD of the transmission frame 13 are TEXTθ, TEXT/ will be described.

Since data is sent via the R line l/, the transmission device 10 in the slave state writes the data to the reception buffer ioi by the function of the reception control circuit 103. When turned on, broadcast transmission is performed, or when the address is different from the address of the own transmission device, the received data is immediately sent as is to the R line 7 through the transmission control circuit 10≠. If it is the own address, the sixth part BCC of the transmission frame 13 is used to check whether there are any errors in the data written to the reception buffer 10/. If received correctly, the first part CM of the transmission frame 13 is transmitted through the transmission control circuit 10≠.
ACK D, the second part SA is the address of the mask, i.e. the value of the third part PA of the received transmission frame 13;
0 broadcast transmission sending the third part PA as its own address or the data sent to it is in the receive buffer, 10/. This data is passed to the equipment connected to the transmission device IO through the transmission control circuit ior.

When performing loopback transmission as shown in FIG. 1(b), L line/:1. Data also flows. At this time, the data received from the reception control circuit iot is sent directly to the transmission control circuit 10! Next, the operation when the transmission device 10 in the masked state transmits data will be explained with reference to the same drawing.

It is assumed that data to be transmitted has been written from a device connected to the transmission device 10 to the transmission back 7102 via the reception control circuit 107. Writing to the transmission buffer 102 is possible whether the transmission device 10 is in a masked or slaved state.

The data to be transmitted is in the 13th transmission frame! submolecule E
XT, and the other parts are generated by the transmission device IO.

If this data is to be sent to a specific transmission device, the second part SA of transmission frame /3 is set to that address. When sending to all slaves, this value is
0'' for broadcast transmission. When the transmission frame 13 is assembled in this way, it is transmitted to the R circuit 1/ via the changeover switch 10 and the transmission control circuit 10IA.

The method of confirming whether transmitted data has been correctly received differs between broadcast transmission and n:n transmission. In broadcast transmission, when the data returns via all slave transmission devices, this data is written to the reception buffer 10/ via the reception control circuit 103. If this content and the content of the transmission buffer 102 match, it is assumed that the transmission was correct; , is assumed to have been correctly transmitted when received from the reception control circuit 103.

The master transmission device that holds the token has the right to transmit. When the transmission is completed, the master transmission device sends the first portion CMD of the transmission frame 13 as a token TOKEN to the R line 1/ via the transmission control circuit 10≠. The transmission device 10 that has received the token performs the above-mentioned masking process if there is transmission data in the transmission buffer 1O2 of its own device.

When there is no transmission data, the received token is immediately sent to mu R times via the transmission control circuit 104A.By the way, in order to express the operation of one transmission device 10 precisely and easily, the state of its operation will be described below. The transmission device 10 according to the present invention, which is suitable to be divided into a plurality of states and described as detailed operations and state transitions in each state, will also be explained with reference to the state transition diagram shown in FIG. μ. .

All transmission devices IO can take any of the following seven states. Transitions between states are shown by paths Pij in FIG.

O: Off: Power off state /: Quiet: When the initialization process is completed and the self-diagnosis result is normal.

Coni Master Check: Sends a test frame, checks operable circuits, and creates line configuration data.
This data is transmitted to the operational transmission device 10.

Generate a token.

3 Nisrep check...... Processing of test frame acceptance.

Hiroshi: Online master...Transmission device that holds tokens. When there is data to be transmitted within its own transmission device, it is assembled into a transmission frame 13 and transmitted.

j Online slave...Receives the transmission frame 13 sent from the online master tag.

t: Down . . . Line abnormal state 0 The operation of the transmission device 10 described above is the operation in a steady state when transmission is normally performed.

FIG. 7 is a state transition diagram showing the operation of the transmission device of FIG. 3.

In the state transition diagram shown in Figure 1, the transmission device 10 having the transmission right called mask is in the state of online master p, and the transmission device 10 receiving data called slave is in the state of online slave j. When the mask passes the token to the downstream slave transmission device 10, the route is P1
15. When the slave receives this, the confirmation means route is p511.

Next, the operation of the transmission device 10 of the present invention when starting up a line will be described.

The operation of starting up the line occurs at the following three points.

■ When all transmission devices are powered on.

■ When an abnormality occurs in the line, disconnect the abnormal part and start transmission using only the normal part.

First, we will discuss case ■ in detail.

When each transmission device IO is powered on, it initializes its own device and performs self-diagnosis. This is the OFF state in FIG. μ. If it is determined to be normal by self-diagnosis, it transits to the wait state/through the route POI.

In the wait state/, it is checked whether there is an activation request to start transmission. The startup request may be when the operator presses the start switch attached to the transmission device 10, or data sent from a device connected to the transmission device R10, etc.
The method of making the request is not included in this invention.

For example, if the start switch is pressed b, the device immediately transitions to the master check state λ via path P12. If the start switch is not pressed, the control waits until the start switch is pressed or for receiving data (hereinafter referred to as a test frame) in which the first part CMD of the transmission frame 13 is test (TEST) from another transmission device 10.

In master check state 2, a line test is performed. The line test is an operation of checking the status of the transmission line with other transmission devices 10 using the R line 11 and the L line/co, and generating line configuration data representing the line status that allows transmission. When the line test starts, the transmission device 10 in the master check state 2 transmits a test frame, so all the transmission devices IO in the wait state 1 transition to the slave check state 3.

The details of the line test will be described later.

When the line configuration data is created through a line test, R line l
When the loop-shaped transmission line consisting of ffJu and L line and all the transmission devices IO connected to it are normal as shown in Figure 1(a), all the transmission devices are connected via R line ffJu. Send line configuration data to IO. When there is an abnormality in the transmission path as shown in Figure 1(b), if the device in master check state 2 is 5TNO, the transmission device S in slave check state 3 is connected to R line l/, and slave check L line 7.2 up to transmission device 5TNi+1 in state 3
Send line configuration data via.

The line configuration data is the j-th part of the transmission frame 13 EX
T and the first part CMD is the circuit configuration 'CNF)
, the second part SA is "0.11" of the broadcast transmission.
It is. The transmission device 10 in the master check state sends the transmission frame 13 to the R line l via the transmission control circuit 10.
This data sent back to the transmission device 10 in all the slave check states 3 is sent to the reception control circuit 1.
03 to receive buffer 10/. Compare the previously sent transmission frame and the contents of the receive buffer, and if they match, it is assumed that the line configuration data has been transmitted correctly, and the system transitions to the online mass tag state via path P211 in Figure ≠. . On the other hand, when the transmission device IO of slave check 3 receives the line configuration data, it transits to the state of online slave j via path P35. This completes the line startup, and the subsequent operation is based on the token being placed on the line. , and a transition car occurs between the states of online master≠ and online slave j.

Next, we will discuss case (2) above when setting up a line.O When transmitting in the online mask state≠ and the online slave state, abnormalities may occur on the line0.The following abnormalities may occur0. Transmission power was lost due to a break in the transmission line or a failure in the transmission equipment.

■ Noise entered the transmission path and a bit/node error occurred in the transmitted data 0 @ Token disappeared 0 ■ Multiple tokens were generated and each transmission device sent them.

If there is a failure in the transmission device 10 in the online mask state G, and in the case of ■, the transmission device io in the online master state
can detect these anomalies.

When an abnormality is detected, a transition is made to the master check state via path P112 in the figure, and a circuit check is performed to discover the abnormal part. When the other transmission devices 10 in online slave state j start line checking, they transit to slave check state 3 via path P53.

Since the subsequent operations have already been described, they will be omitted. If the transmission device in the 0 online mask state ≠ fails or if there is a bi-soto error while transmitting the token, the @ token will disappear. In addition, there is a possibility that a crack may occur due to some reason. In this case, the path Pli6 t
All the transmission devices 10 transition to the down state B via P56. Each transmission device 10 starts a start-up timer (not shown) while waiting for reception. The startup timer has a different value for each transmission device IO, and this time TMO
is the address value (in seconds) of TMQ=kX transmission device 10. The value of k is determined by the operating speed of the transmission device 10, the delay time of the transmission path, the number of transmission devices 10 connected to the line, etc.

The transmission device 10 whose start-up timer has timed out transits to the master check state via path P62 and immediately enters a line check. The other transmission devices 10 that do not come in because their start-up timers have timed out receive test frames from the transmission device 10 in the master check state λ, so they stop their timers and change to the slave check state via path P63. Transition to 3. The subsequent operations have already been described, so they will be omitted.

Figure 5 represents the start-up operation described above in the form of a flowchart.

Finally, the line test operation will be explained with reference to FIG.

The transmission device MASTER in the master check state λ is first R
The test frame FOI is transmitted from the line /l, and the first part CMD of the transmission frame /3 is transmitted from the downstream transmission device 5LAVE/ via the L line/, 2 as an acknowledgment (ACK) data (hereinafter referred to as an acknowledgment frame). ). If there is no response within the predetermined time TM1,
It is assumed that there is something wrong with the transmission device or the R lines and L lines between them. In order to prevent transient errors caused by noise or the like, the same frame is retransmitted multiple times when there is no response.

When the downstream transmission device 5LAVE/ receives the test frame, it puts its own device address in the third portion PA of the transmission frame 13 and transmits an acknowledgment frame Fil to the upstream station. The upstream station MASTER receives this acknowledgment frame F.
Upon receiving il, it sends an acknowledgment frame FO2. Upon receiving the frame FO2 from the downstream station 5LAVK, the upstream station MASTER performs the same operation on the downstream station 5LAVE. Transmission device 5LA
VII, transmits the acknowledgment frame F21 from 2 to the transmission device 5L.
When AVE/ receives it, it sends it to the transmission device MASTER in master check state 2 via the L line/co.

All of the following transmission devices 5LAV in slave check state 3
The same operation as described above is performed for EFi.

In this way, the transmission device MAS in master check state λ
TER is the acknowledgment frame Flip “21*F31
Line configuration data representing the line status that allows transmission is generated from the line.

〔Effect of the invention〕

Thus, according to the present invention, start-up can be performed smoothly and quickly without the need to specially install a transmission device for monitoring and control on the line, and simple processing can be performed without using special equipment for start-up. This can be achieved with

[Brief explanation of drawings]

Figures 1 (a) and (b) are overall block diagrams when the transmission device according to the present invention is connected, Figure 2 is a diagram showing the format of data flowing through the transmission path, and Figure 3 is an embodiment of the present invention. A block diagram showing the internal configuration of the transmission device in the example, Fig. ψ is a state transition diagram of the operation of the device in Fig. 3, Fig. 5 is a flowchart showing the start-up operation, and Fig. 3 is a line and transmission during test operation. FIG. io...transmission device/no...8 lines/2...5 lines/3...transmission frame lμ...failure occurrence part 10/...reception buffer io, z...transmission buffer 103 , IOt, 107...reception control circuit ioμ
, 103.10... Transmission control circuit lOde... changeover switch. Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] l A plurality of transmission devices are connected by a double loop-shaped transmission line in which the transmission directions are mutually reversed, and the right of transmission is divided into seven parts in the system.
In a transmission device that is controlled to establish by receiving only one existing token, when all the transmission devices are in the initial state such as after power is turned on, by starting transmission from any transmission device, A loop transmission device characterized in that, when there is an abnormality in the transmission path, each token is generated after a delay time unique to each transmission device. The transmission device that generated the cotoken checks the status of the transmission path with other transmission devices and obtains information indicating the status of the operable transmission path. 2. The loop transmission device according to claim 1, wherein the loop transmission device notifies by circular transmission that is transmitted to all the devices.