JPS6016744A - Node station of loop network - Google Patents

Abstract

PURPOSE:To obtain an economical network by constituting the inside of a node of a bus transmission line and a loop transmission line in the node accommodating plural terminal devices connected to a loop network. CONSTITUTION:A signal decoded by a decoder 111 is fed to a transmission control circuit 110. When the signal is not a token, a data selector 113 is controlled and transmitted to a transmission line 7 via a coder 112 and also to a bus 121. Terminal interfaces 13-15 fetch a signal addressed to the own to a buffer 142. When the signal is a token, the transmission control circuit 110 transmits the token to loop transmission lines 123a-c. When an access control circuit of the terminal interfaces 13-15 receives the token and there is data to be transmitted, the circuit transmits a signal to the loop transmission line 7 via the buffer 142, a gate 143 and a bus 122.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the configuration of a node station in a loop network, and more particularly to a node station accommodating a plurality of terminals.

As shown in FIG. 1, the loop-like network consists of a plurality of mate stations 1. 2. 3. 4. 5. 6 and a loop-shaped transmission line 7, and has the advantage that broadband communication can be provided by using, for example, an optical fiber cable as the loop-shaped transmission line 7. Each terminal is accommodated in the loop network via these node stations, but providing one node station for one terminal poses a problem in terms of economy. For example, if the transmission line 7 is an optical cable, each node station requires an optical-to-electrical converter for converting an optical signal into an electrical signal, and an electrical-to-optical converter for performing the reverse conversion.

These converters are expensive, and the configuration of one node station per terminal results in an expensive system. Therefore, a configuration in which one node station accommodates a plurality of terminals as shown in FIG. 2 becomes practical. The node station 10 in FIG. 2 includes a transmission path interface circuit 11 that performs electrical-to-optical conversion and mutual conversion between transmission codes and digital signals, and a terminal ink face circuit 13 that accommodates terminals 130, 140, and 150, respectively. ,1
4.15 and a common access circuit 12 through which these terminal interface circuits access the transmission path 7. In such a configuration, in order to construct a more economical network, the expensive transmission line interface circuit 11 is required.
It is necessary not only to share the common access circuit 12 among a plurality of terminals 130, 140, and 150, but also to simplify the configuration of the common access circuit 12 and reduce its cost. That is, since the common access circuit 12 is a fixed part that does not depend on the number of accommodated terminals, an increase in the price of the common access circuit 12 causes a problem in that the initial investment of the network becomes expensive.

The present invention aims to simplify the configuration of the fixed part of a node station that accommodates a plurality of terminals, and to reduce the cost of the part of the network price that does not depend on the number of terminals. A node station according to the present invention includes a transmission line interface circuit connected to a loop-shaped transmission line, a plurality of terminal interface circuits provided corresponding to the plurality of terminals, and a plurality of the transmission line interface circuits and the plurality of terminal interface circuits. The communication path is composed of a bus-like communication path and a loop-like communication path that connect the terminal ink 7 and the chair circuit, and the transmission path ink face circuit supplies a transmission right acquisition permission signal to the loop-like path (g path). The terminal interface circuit connects the signal on the loop-shaped transmission path to the transmission path ink hook circuit and 1)
The terminal interface circuit receiving the transmission request via the J bus path 1d and capturing the transmission 4R acquisition permission signal from the loop communication path, transmits the transmission request to the path communication path and the transmission path interface circuit. A signal to be transmitted via the circuit is sent to the loop-shaped transmission path.

Further, the node station according to the present invention includes a transmission line interface circuit connected to the loop-shaped transmission line, a plurality of terminal ink seven chair circuits provided corresponding to the plurality of terminals, and a transmission line interface circuit connected to the loop-shaped transmission line. 4.14 consists of a path-shaped communication path that connects an interface circuit and a plurality of terminal ink face circuits, and a loop-shaped communication path that connects the terminal interface circuits, and the terminal interface circuit is configured in the loop-shaped communication path. A terminal ink face circuit that receives the signal of the transmission path via the transmission path interface circuit and the path-shaped communication path, and that the transmission right acquisition I/-signal circulates through the loop-shaped communication path, and a transmission request is generated. starts transmission right acquisition control when the transmission right acquisition permission No. 43 is captured by the loop communication path, and after acquiring the transmission right, transmits a signal to be transmitted via the path communication path and the transmission path ink face circuit. is transmitted to the previous h[] loop-shaped transmission path, and the transmission right acquisition permission signal is returned to the loop-shaped transmission path.

Next, the present invention will be explained in detail with reference to the drawings. FIG. 3 shows a first embodiment of the present invention. FIG. 4 shows the configuration of a signal block used in the present invention, and FIG. 5 shows a timing diagram in this embodiment.

The node station in FIG. 3 has an input terminal 100 and an output terminal 101 connected to the transmission path 7, and includes a post-encoder 111 that converts a transmission code into a digital signal, an encoder 112 that performs the inverse conversion, and a transmission Control circuit 110, data selector 113, terminal interface circuits 13, 14, 1
5. Bus-like communication paths 121, 122 and loop-like communication path 1
23a, 123b, 123c, and 123d. When the transmission line 7 is an optical fiber couple, the decoder 111 also performs optical-to-electrical conversion, and the encoder 112 also performs electrical-to-optical conversion. To explain this configuration in relation to FIG. 2, the transmission line interface circuit 11 in FIG.
are a transmission control circuit 110, a decoder 111, an encoder 112,
The common access unit 12 has path-like communication paths 121, 1.22 and loop-like communication paths 123a, 123b.

It is composed of 123c and 123d. In addition, the third
In the figure, terminal ink face circuits 13, 14. 1
5 and the terminals 130, 140, and 150 are omitted to simplify the drawings. Terminal interface, Il'i 114 is access control circuit 141
．． Buffer 142 for storing transmitted data and received data
and the gate 143 of the tristate (or oven collector). The output of gate] 43 is connected to path-like communication path 122 and buffer 142
The receiving section of is connected to the path-like communication path 121. When the gate 43 is enabled under the control of the access control circuit 141, it sends the transmission data from the transmitting section of the buffer 142 to the path communication path 122, and when it is disabled, it outputs level l. Terminal Ink 7 Eighth Circuit 13.1
5 also has the same configuration as the terminal interface circuit 14, and the access control circuit and transmission control circuit 110 of these terminal interface circuits have communication paths 123a, 1
23b, 123c, and 123d are connected in a loop. FIG. 4(a) shows a signal block for communication between node stations.

This signal block includes a start flag SF, destination address DA, originating address SA, information INFO, and end flag E.
F and the bit TK (TK
(b) is a signal (hereinafter referred to as a token) that grants the transmission right, including a start flag 8F, an end flag EF, and a signal indicating that it is a token.
(TK = O), the first wave is formed. Figure 5(a),
(b) shows the signal input to the transmission control circuit 110 and the signal output from the data selector 11.3, and (c), (d), (c), and (f) show the communication path 1, respectively.
The signals on 23a, 123b, 123c, 123d are shown. The operation of the node station shown in FIG. 3 will be explained. The signal on the transmission line 7 decoded by the decoder 111 is supplied to the transmission control circuit 110. If the input signal is not a token (that is, if TK=1), the transmission control circuit 110 transmits the input signal to the encoder 112.
Controls the data selector 113 so that it is supplied to the output 11
4. Multi-control. This bypassed signal is transmitted to encoder 1
12, the signal is converted into a transmission code and supplied to the transmission line 7.

This signal is also supplied to the bus-like communication path 121 at the same time, so that the terminal interface circuits 13, 14, 15 can receive the signals addressed to them in their respective buffers 142. When the transmission control circuit 110 receives the token TKN (signal with bit TK=0) shown in FIG. 5(,),
Control output 114 controls data selector 113 to select bus-like communication path 122 . Therefore, Fig. 5 (
As shown in b), this token TKN is not output from the data selector 113 and is removed from the loop-shaped transmission line 7. When the transmission control circuit 110 captures the token TK, it outputs a transmission right acquisition permission signal (for example, a single pulse) shown by diagonal lines in FIG. 5(c) to the communication path 123a. In this embodiment, the terminal interface circuit that captures the transmission right acquisition permission signal can transmit it immediately, and hence will be referred to as an intra-node token hereinafter.

That is, this intra-node token gives the right to transmit to the bus-like communication path 122. It is now assumed that there are transmission requests from the terminals 140 and 150, and the terminal interface circuits 14 and 15 accommodating these requests are in a state of waiting for transmission. Since the terminal interface 7 chair circuit 13 is not in the state of waiting for transmission, the fifth
As shown in Figure (d), the received intra-node token is directly bypassed and output to the communication path 123b. When the access control circuit 141 of the terminal interface circuit 14 captures the intra-node token, it enables the gate 143 and sends the transmission data B14 in the buffer 142 to the bus-like communication path 122. Note that the transmission data B14 is the fourth
It has the configuration shown in the figure (,). Since only the terminal interface circuit that captures the intra-node token can send data to the bus-like communication path 122, the transmission data B14 may collide with other transmission data on the bus-like communication path 122 and be destroyed. There isn't. This transmission data B14 is multiple outputted from the data selector 113 as shown in FIG. 5(b), and further outputted to the output terminal 101 via the encoder 112. When the transmission of the transmission data B14 is completed, the access control circuit 141 outputs the intra-node token to the communication path 123C as shown in FIG. 5(e). When the terminal interface circuit 15 captures this intra-node token, it sends out transmission data B15 in a similar manner. When the transmission is completed, the intra-node token is output to the communication path 123d and returned to the transmission control circuit 110 as shown in FIG. 5(r).

When the transmission control circuit 110 captures the returned intra-node token, it issues a new token TKN and passes the transmission right to another node station, as shown in FIG. 5(b).

On the other hand, transmission data B14. B15 is supplied to the transmission control circuit 110 after going around the transmission path 7;
If the sender address 8A of this received signal is the address of the terminal it accommodates, it keeps the data selector 113 in the selected state of the bus-like communication path 122, so the transmitted data B14.15 goes around the transmission path 7. bus-like communication path 12
1, but is not output from the data selector 113. That is, the transmitted data is removed at the originating node station. On the other hand, the sender address S of the received signal
If A belongs to another mate station, the control output 114 causes the data selector 113 to
Select 1. Therefore, the transmission data B21 and B22 from the other node stations shown in FIG.
It is bypassed as shown in Figure (b).

FIG. 6 shows another example of the loop-shaped communication path used in this embodiment. The loop-shaped communication path in FIG. 6 is composed of a shift register 124 and a bus 125 that supplies the shift block of the shift register 124, and the outputs 126, 127, and 128 of each stage of the shift register 124 are respectively connected to the terminal ink 7 and 8 circuits 13. ．． 14. 15. When the transmission control circuit 110 captures the token TKN,
Level 1 data indicating an intra-node token is supplied to the shift register 124, and a clock pulse is sent to the bus 125.

Therefore, only the output 126 of the shift register 124 becomes level 1. The terminal interface circuit 13 sends out a chrono pulse to the bus 25 when the output 126 becomes 1 but is not in a waiting state for transmission, or when the transmission is completed. Therefore, the L shift register 124 is shifted by one stage L output 12 in the node of level 1.
7 is output. Similarly, the node 1.-kun shifts the shift register 124 and transfers it to the transmission control circuit 110.
Return to In this case, only the terminal interface circuit that has captured the intra-node token can send a clock pulse to the bus 125, so there will be no terminal ink face circuit that cannot capture the intra-node token.

FIG. 7 shows a second embodiment of the invention. In this embodiment, a tri-state (or open collector) gate 144 that gates the transmission request signal from the access control circuit 141 of each terminal interface circuit and a bus 129 that commonly connects the output of the gate 144 are added. 3rd except
It has the same configuration as the node station shown in the figure. Each terminal interface circuit connects the gate 14 when a send request occurs.
Set Nonosu 129 to level 0 through 4. Since the bus 129 becomes O level by the blood-phase OR logic, the transmission control circuit 110 can know that a transmission request has occurred in any of the terminal interface circuits in the node station by detecting the O level of the bus 129. . Transmission control circuit 11
0 controls the capture of the token TKN only when the O level of this bus 129 is detected, and if it is not detected,
Token TKN is bypassed. As a result, in this embodiment, if there is no transmission request within a node station, the token TKN is immediately passed to another node station.

Note that the access control circuit 110 of the terminal interface circuit where the transmission request has occurred supplies level O to the gate 144 and outputs level A when capturing and recirculating the intra-node token.
/l. In the embodiments shown in FIGS. 3 and 7, the bus-like communication paths 121 and 122 have been described as one bus, but as shown in FIG. When the serial converter 116 is provided, the bus-like communication paths 121 and 122 may each have a parallel bus configuration. In this case, each terminal interface circuit is
It is possible to send and receive signals at a speed slower than the signal speed of .

Next, a mate station used in a loop network described in Patent Application No. 57-212364 will be explained. Such a network includes node stations 1. 2. 3. In addition to 4°5.6, an example of a frame configuration of a signal block used for network synchronization signals and plywork is shown. Figure (a) shows a signal block for communication between node stations, and Figure (b) shows a signal block for communication between nodes.
shows the configuration of the trigger signal from the clock station 8. Preamble signal PR1 synchronization pin (8Y) and priority information PI are added to the frame configuration shown in FIG. Supplied as one. Each node stage town is 5Y
When detecting =1, the built-in timer is reset and controlled to operate in synchronization with the clock of the clock station 8. Furthermore, priority information PI indicates the priority of communication. In this loop network, each node station acquires the right to transmit by detecting a no-signal state immediately after a signal block has passed. A node station in such a network will be explained. FIG. 11 shows a third embodiment of the present invention. Signal blocks from other node stations and clock station 8 are sent to decoder 11
1 and then supplied to the terminal ink face circuit 13.14.15 via the bus-like communication path 121. Therefore, each terminal interface circuit can receive the signal block addressed to itself, and can also detect the synchronization signal (sY=1) and the priority information P. Each terminal interface circuit resets a built-in timer (not shown) upon detecting a synchronization signal. Still, when each terminal interface circuit, such as the terminal ink face circuit 14, is in the receiving state, the input of the tri-state (or open collector) gate 145 is set to level 0, and the bus 115 is set to level 1. The data selector 113 selects the output of the decoder 111, that is, the bus-like communication path 121, because the bus 115 connected to the selection control input is at level 1. Therefore, signal blocks from other node stations and clock station 8 that are supplied to input terminal 100 are output to output terminal 101 as they are.

Next, the transmission operation of each terminal interface circuit will be explained. Assume that a transmission request is now issued to the terminal ink 7 and eighth circuits 14 and 15. The access control circuit 141 of the terminal interface circuit 14 receives the output 1 of the data selector 113.
16 and compares the priority information PI indicated by the signal block passing through this station date with the priority of the transmission request, and if the priority of the transmission request is the same or higher, level 1 is set to 144. The signal is sent to set the bus 129 to level O.

When the transmission control circuit 110 detects the level O of the bus 129, it sends a permission signal to the communication path 123a to permit the start of transmission right acquisition control. This permission signal is captured by the access control circuit 141 via the terminal interface circuit 13 and the communication path 123b. When the access control circuit 141 captures the permission signal, it senses the bus 115. this is,
This is to determine whether the output of the data selector 113 is a signal block from another node station. In this case, the bus 115 is at level 1, indicating that the output 116 of the data selector 113 is the signal supplied from the input terminal 100, ie the signal block from the station. In this case, access control circuit 141
monitors the output 116 of the data selector 113, and when it detects that the end flag EF has passed, it enables the gate 143 and sends out the pudding signal PR, and also sets the input level of the gate 145 to OK, setting the bus 115 to level 0. When the bus 115 becomes level 0, the data selector 113 selects the bus-like communication path 122 and gate 143
The output preamble signal PR is then output. At the same time, the access control circuit 141 detects whether a preamble signal P It of a signal block is subsequently received from another node station over the bus-like communication path 121. When the preamplifier signal PR from another node station is detected while the preamplifier 1r+jpn5L is being output, the gate 143 is immediately disabled to stop sending out the preamplifier signal P, and the bus 115 is returned to level 1. Therefore, signal blocks from other node stations are passed through the data selector 113 to the output terminal 101.
supplied to Below is a series of controls. If the preamble signal PR from another node station controller is not detected, the transmission right is acquired and the bus 115 is level 0.
Send the Iba block to be transmitted while keeping it as . A permission signal is sent to the communication path 123G at the time when a certain portion of the signal block, for example, the header up to the originating address SA, is sent. This grant signal is captured in the terminal interface circuit 15. When the access control circuit 141 of the terminal interface circuit 14 completes transmission, it returns the input level of the gate 144 to 0. However, since the terminal interface circuit 15 is in a state of waiting for transmission, the bus 129 remains at level 0. In addition, the access control circuit 141 sets the input level of the gate 145 to 1 and the bus 115 to level 0 until the signal block sent out goes around the transmission path 7 where it is transmitted in a loop and is received via the bus-like communication path 121. Hold. When the terminal ink face circuit 15 captures the token, it senses the bus 115.

In this case, the bus 115 is at level A10, which indicates that the output of the data selector 113 is a signal block from the terminal ink face circuit in the same node station controller, in this case the terminal ink face circuit 14. ing. A signal block starting with the terminal interface preamble signal PR is sent out, and the input level of a gate (not shown) corresponding to gate 145 is set to 1.

In this case, even if a signal block is detected on the bus-like communication path 121, the terminal interface circuit 15 does not need to stop transmission because it is a signal block that has been sent out from the same node station and has made one circuit. Similarly to the terminal ink face circuit 14, the terminal ink face circuit 15 also supplies a permission signal to the communication path 123d after starting transmission, and also changes the input level of the gate (not shown) corresponding to the gate 144 after the transmission is completed. After the signal block transmitted by itself has circulated through the transmission line 7, the input level of the gate (not shown) corresponding to the gate 145 is set to 0. Therefore bus 1
29 becomes level 1 after all terminal interface circuits that wish to transmit have finished transmitting. Also, bus 11
5 returns to level 1 after being removed from all signal blocks sent out from this node station, and data selector 113 selects the output of decoder 111. When the permission signal is returned after the transmission control circuit 110 bus 129 becomes level 1, that is, after all transmissions are completed, the supply of the captured permission signal to the communication path 123a is stopped.

FIG. 12 shows a fourth embodiment of the present invention. In this example,
This embodiment is the same as the third embodiment except for the permission signal circulation method. In this embodiment, the I''i number of permissions 13 constantly circulates through the loop-shaped communication paths 123b', 123c' and 123d'.Terminal interface circuit: acquires the transmission right using the 3° method and performs G control. After acquiring the start, perform the transmission.

After acquiring the transmission right, the permission signal is returned to the loop communication paths 123b', 123c', and 123d'.

As described above, according to the present invention, since the common access section is composed of only bus-like communication paths and loop-like communication paths, its cost is extremely low, and fixed costs that do not depend on the number of terminals accommodated can be reduced. A more economical network can be provided.

[Brief explanation of the drawing]

1 and 9 are diagrams showing the configuration of a loop network, and FIG. 2 is a block diagram of a node station,
FIG. 3, FIG. 7, FIG. 11, and timing diagrams of the first embodiment, FIG. 6 is a diagram showing another example of a loop-like communication path, and FIG. 8 is a diagram showing a plurality of bus-like communication paths. FIG. 2 is a diagram illustrating a bus configuration. In FIGS. 1 to 3, FIGS. 6 to 9, and FIGS. 11 and 12, I, 2. 3. 4. 5. 6゜1
0 is a node station, 7 is a loop-shaped transmission line, 11 is a transmission line ink face circuit, 12 is a common access circuit,
13. ] 4. 15 is a terminal ink face circuit, 1
30, 140, 150 are terminals, 110 is a transmission control circuit, I1. ] is a decoder, 112 is an encoder, 113 is a data selector, 14 is an access control circuit, 142
id Hanofha 121, 122 Babasu Street (I Road, 123a, 123b, 123c, and 123
b', 123c', and 123d' are parts of a loop-shaped communication path; 143, 144, and 145 are gates; 124 is a shift register; 116 is a parallel/serial converter; 115 is a serial/parallel converter; 8 is a clock station. shows. Fig. 1 Fig. 2 150 140 130 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Off Fig. O Fig. 8 Fig. O 9 Fig. 10 Fig. 11

Claims (1)

[Claims] 1. In a node stage provided in a loop network and accommodating a plurality of terminals, the node station includes a transmission line interface circuit connected to a loose transmission line and a transmission line interface circuit corresponding to the plurality of terminals. It is composed of a plurality of terminal interface circuits provided as a plurality of terminal interfaces, and a bus-like communication path and a loop-like communication path that connect the transmission line interface circuit and the plurality of terminal interface circuits, and The transmission line interface circuit supplies a transmission right acquisition permission signal to the loop-shaped communication line, and the terminal interface circuit supplies the signal on the loop-shaped transmission line via the transmission line interface circuit and the bus-shaped communication line. Along with receiving
After the terminal ink 7 face circuit in which the transmission request has occurred captures the transmission right acquisition permission signal from the loop-like communication path, it should transmit it via the bus-like communication path and the transmission line ink face circuit. 2. When the transmission line ink face circuit acquires the transmission right from the loop transmission line, the transmission right acquisition permission signal is transmitted to the loop network. At the same time, when the transmission right acquisition permission signal goes around the loop communication path and returns, the acquired transmission right is returned to the loop transmission path, and the terminal ink face circuit transmits the transmission right. 2. The loop network according to claim 1, wherein the transmission right acquisition permission signal is transmitted when the transmission right acquisition permission signal is captured, and after the transmission is completed, the transmission right acquisition permission signal is returned to the loop communication channel. station. 3. Only when there is a transmission request from at least one terminal interface circuit among the plurality of terminal interface circuits, the transmission line interface circuit controls to capture the transmission right on the loop-shaped transmission line. A node station of a loop network according to claim 2, characterized in that the node station performs the following. 4. The transmission line ink face circuit supplies the transmission right acquisition permission signal to the loop communication path when there is a transmission request from at least one terminal interface circuit of the plurality of terminal ink face circuits, and When the terminal interface circuit that sent the transmission request captures the transmission right acquisition permission signal through the loop communication channel, it starts transmission right acquisition control, acquires the transmission right, performs transmission, and issues the transmission right acquisition permission. A node station of a loop network according to claim 1, characterized in that the node station returns a signal to said loop-shaped communication path. 5. In a mate station installed in a loop network and accommodating a plurality of terminals, the node station has a transmission line interface circuit connected to a loop-shaped transmission line and a plurality of transmission line interface circuits provided corresponding to the plurality of terminals. It is composed of a terminal interface circuit, a path-like communication path that connects the transmission line interface circuit and a plurality of terminal interface circuits, and a loop-like communication path that connects the terminal interface circuits to each other. , the terminal ink face circuit receives the signal of the loop-shaped transmission path via the transmission path interface circuit and the path-shaped communication path, and a transmission right acquisition permission signal circulates through the loop-shaped communication path, and transmits the signal. When the terminal interface circuit in which the request has occurred captures the transmission right acquisition permission signal from the loop-shaped communication path, it starts transmission right acquisition control, and after acquiring the transmission right, controls the transmission right acquisition permission signal from the path-shaped communication path and the transmission path interface. A node station of a loop network, characterized in that a signal to be transmitted via a circuit is sent to the loop-shaped transmission path, and the transmission right acquisition permission signal is returned to the loop-shaped transmission path.