JPH03201745A - Ring type lan - Google Patents

Abstract

PURPOSE:To simplify data transfer by providing a data input/output terminal and a control signal input/output terminal to a communication station and providing an interface directly interfacing the data input/output terminal and the control signal input/output terminal to a peripheral equipment. CONSTITUTION:When a data of peripheral equipments 51-54 connecting to communication stations 11-14 to a peripheral equipment connecting to other communication station, the communication station receives a direct data via the interface from the peripheral equipment at first and the data is stored in a frame having an address of other communication station designated in advance and the resulting data is sent. Then the reception station receives the frame to detect the data and outputs the data directly to the peripheral equipment. Thus, the communication stations 11-14 are connected simply to the peripheral equipments 51-54 and the data inputted to and outputted from the peripheral equipment is transferred simply and efficiently.

Description

Detailed Description of the Invention The second invention in the industrial +lJ field is a ring-type LA in which a plurality of communication stations are connected in a ring shape through a transmission path and data communication is performed between the stations.
In particular, the present invention relates to a ring-type LAN that connects peripheral devices to each communication station and can efficiently transfer data input and output to each peripheral device.

``Conventional technology'' Figure 3 shows an example of the configuration of a conventional ring type LAN. Transmission lines connected in a ring shape using twisted pair wires or optical fiber cables, 3 to 34 are CPUs (central processing units) that control the communication stations 1. to 14, and 4. to 43 are CPU 3.
rtoM in which software used in □-34 is stored; 5-54 various peripheral devices such as keypads and panel displays; 6. ~64 is a bus.

In such a configuration, each CPU 3 . ~34 is performed using software stored in ROM4+~44.

``Problems to be Solved by the Invention'' By the way, in the conventional ring-type LA''N described above, there was a drawback that the burden on the peripheral devices 51 to 53 was heavy because the CPUs 3. to 34 had to intervene. .

Therefore, even if you want to easily output a small amount of data manually, for example, when using a peripheral device that is simply connected to the I10 port, there is a drawback that software must be prepared for each peripheral device 51 to 54. Ta.

This invention was made in view of the above-mentioned circumstances, and provides a ring-type LAN that can easily connect peripheral devices to a communication station and easily and efficiently transfer data output to peripheral devices. It is intended to.

Means for Solving Problem 1" This invention connects a plurality of communication stations in a ring shape through a transmission path, assigns a predetermined address to each of the plurality of communication stations, and attaches a peripheral device to each of the plurality of communication stations. In a ring type LAN that connects a plurality of communication stations and transfers data input and output to each peripheral device between the plurality of communication stations, the communication station has a data input/output terminal for inputting and outputting data, and a terminal for inputting and outputting the data. and a control signal input/output terminal through which a control signal for controlling input/output is input/output, and the peripheral device includes:
The present invention is characterized in that it has an interface that can be directly connected to the data input/output terminal and the control signal input/output terminal.

"Operation" According to the present invention, in order to transfer data from a peripheral device connected to a certain communication station to a peripheral device connected to another communication station, the communication station first transfers data from the peripheral device via the interface. data is input directly to the communication station, and the data is stored in a frame having the address of another communication station designated in advance and sent.

The receiving station then receives the frame, detects the data, and outputs the data directly to the peripheral device.

"Embodiment" Before describing an embodiment of the present invention, a basic idea for solving the above-mentioned problems will be explained.

There are two basic formats for ring-type LANs: tokens and frames. Among these frames, there are frames for transferring data and ring-type LA frames.
There is a MAC (Media Access Control) frame used for managing N. The format of the MAC frame is shown below.

SD ACFCDA SA INFOFC8ED FS
Here, SD is a starting delimiter (1 octet) indicating the start of a frame, and AC has information such as frame priority and reception of reservations from other communication stations, as well as information for distinguishing between tokens and frames. FC is a frame control [1 octet] that has information such as the frame type.

Further, DA and SA are a destination address and a source address (2 octets) that have information on the address of the data destination and source, respectively, and INFO is information to be transmitted.

Additionally, the FCS is a frame test sequence (2 octets). This information is used to test whether information has been dropped or changed during frame transfer.
FC, DA, SA, and INF excluding the start frame sequence and end frame sequence among frames
The part O is the object of inspection.

In addition, ED is an ending delimiter (1 octet) indicating the end of the frame, and PS is a frame status (1 octet) that holds information such as whether the frame has been read or not and is used for determining abnormality.

Therefore, in the present invention, the above-mentioned MAC frame is attached with data input/output from a peripheral device, and is transferred on the ring, and transmitted to a pre-designated communication station.

The receiving station then receives the MAC frame, detects the data, and outputs the data directly to the peripheral device.

By adopting the above concept, data of peripheral devices can be easily transferred without using a CP or software.

Here, the MAC frame used for inputting and outputting data from the peripheral device described above to the communication station will be referred to as an input/output MAC frame.

Next, among the input/output MAC frame formats described above, the destination address (DA) and information (INFO) fields, which are particularly relevant to the present invention, will be explained in more detail.

(a) Destination address (DA) GFAAAAAAAAAAAAAAA If G = "0", F and 14 A's are addresses of individual communication stations, and if G = "l" and F = "0", 14 A's are group addresses. In the address, G="l" and F"1", the 14 A's are interpreted as functional addresses assigned to the network management function and the additional function, respectively.

When a functional address is used as the destination address, data is transferred to the functional unit of the communication station that has the specified functional unit. In addition, the destination address of the input/output MAC frame (
DA) is appended with the address of the communication station l specified in advance by the upper layer.

(b) Information (INFO) The information (INFOr) field of the MAC frame contains information such as commands and responses (hereinafter referred to as vectors) that are transferred for managing the media access (MAC) layer. It consists of the format shown below.

VL VI SVL SVI 5VV---SVL S
VI 5VV(i)VL is 16-bit binary,
Represents the number of octets in the vector, that is, the vector length.

0004H≦VL≦FFFFH (ii) Vl is a 2-octet vector ID divided into three fields.

ddddsssscccccccc dddd is a destination class, and contains an identifier indicating which functional unit in the destination communication station the frame is to be passed to.

5sss is the transmission source class, and contains the functional unit identifier of the communication station on the transmission side.

Also, CCCC'CCCC contains a vector code indicating the function. In addition, the vector ID (Vl
) is 9961H.

(iii) SVL is the subvector length. A subvector is information for adding more detailed information to a vector. However, there may be no subvectors.

Further, the subvector length is expressed in 8-bit binary as the length expressed in the number of octets of the subvector.

The length also includes SVL.

(iv) SVI is a 1-octet subvector ID. Furthermore, the input/output MAC frame subvector ID (SVI
) is 68H.

(v) S V V is a subvector value and a parameter of the subvector. Note that the subvector value (SVV) of the input/output MAC frame includes 2 input/output signals from peripheral devices.
Octets of data are attached.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a ring type LA according to an embodiment of the present invention.
A block diagram showing the configuration of N, FIG. 2 is a block diagram showing the configuration of communication station l in FIG.
FIG. 2 is a block diagram showing the configuration of
Components corresponding to those in FIG. 3 are given the same reference numerals, and their explanations will be omitted. In FIGS. 1 and 2, 7 is a LAN connection unit, which is connected to the transmission line 2 and receives the signal SFT transferred from another communication station I, and receives the signal SFT transferred to the other communication station I. Control transmission. Reference numeral 8 denotes a data processing unit, which processes the received data DR received and decoded by the LAN connection unit 7 and the transmitted data DT to be transmitted to another communication station 1.

Further, in the LAN connection unit 7, 9 is a receiving unit that receives the signal SFT transferred via the transmission path 2, and IO is a receiving unit that receives the signal SFT transferred via the transmission path 2.
F? Frame/token bit string F/TB A
11 is a received bit analysis unit that constantly inspects the frame/token bit string F/TB, detects timing signal St8 regarding the start/end of the frame/token bit string F/TBA, and detects the ring priority. Degree P
, and the reservation priority level R1 is detected and generated, and the frame bit string FBA constituting the frame is extracted.

Furthermore, 12 is a reception control unit, and the frame bit string F
BA is input, it is determined whether this frame bit string FBA is addressed to the local station, and received data DR addressed to the local station is output. I3 is a received data output unit which inputs the received data DR and outputs it to the data processing unit 8 based on the reception control signal RCTL given and outputted from the data processing unit 8.

In addition, 14 is a frame/token bit string F/TB
A bit delay unit 15 rewrites bits while relaying A, and inputs the transmission data DT to be transmitted and the transmission control signal TCTL output from the data processing unit 8,
A transmission data input section 16 outputs transmission data DT based on a transmission control signal TCTL, and 16 is a transmission control section that generates a token bit string TBA and also outputs a transmission instruction signal TS and transmission end outputted from the transmission data input section 15. By outputting the data request signal DR to the transmission data input section 15 based on the signal TE, the transmission data D□
is input, a frame bit string FBA is generated and output according to the token ring protocol. This frame bit string FBA is generated based on the data priority P extracted from the transmission data DT, the ring priority Pr, the reservation priority Rr, and the timing signal STM output from the reception bit analysis section 7. conduct.

Further, 17 is a transmission reservation unit, whichever is greater of the reservation priority Rr output from the transmission control unit 16 and the data priority Pffi (hereinafter expressed as max[Rr, Pi]).
is input, and the value corresponding to the priority is sent to the bit delay unit 14.
Set the reservation index bit Rt of the frame/token bit string F/TB^ that is being passed.

Reference numeral 18 denotes a transmission selection section that selects and outputs either the frame/token bit string F/TBA output from the bit delay section 14 or the frame/token bit string F/TB output from the transmission control section 16. Note that this selection is performed based on a selection signal S8° output from the transmission control section 16.

Furthermore, 19 is an encoding unit that encodes the frame/talk novi 21 sequence F/TBA output from the transmission selection unit 18;
20 is a transmitter that transmits the output signal SFT of the encoder 19 to another communication station 1 via the transmission path 2.

In addition, in the data processing unit 8, 21 is an input/output frame detection unit, which detects input/output MAC frames from the received data DR and can directly input/output the states of the data input/output terminals of the 3 peripheral devices 5 and the communication station 1. The handshake line 22 is used via the control signal input/output terminal, and n-bit data is outputted via the data input/output terminal while confirming the reception and transfer of data. Reference numeral 23 denotes an input/output frame generation unit, which uses the peripheral device 5 and the handshake line 24 via the control signal input/output terminal, and sends n-bit data via the data input/output terminal while confirming the transfer of data. input to generate an input/output MAC frame.

Further, each of the peripheral devices 51 to 54 has an interface that can be directly connected to the data input/output terminal and the control signal input/output terminal described above.

In addition, each peripheral device 5. It is assumed that the communication stations 11 to 14 with which the communication stations 11 to 14 perform data communication are specified in advance. That is, the destination address of the input/output MAC frame mentioned above (
DA) has already been specified by the upper layer, and f two consecutive communication stations 11~
Assume that 14 addresses are attached.

In such a configuration, peripheral devices 5. connected to the communication station 11. data to the peripheral device 5 connected to the communication station 13
I will explain the trick when transferring to 3.

First, the peripheral device 5□ connects the communication station 11's handshake line 24. communication station using 1. After confirming that a reception OK (ready) signal is output from the data processing unit 8, predetermined n-bit data is output.

Thereby, the input/output frame generation unit 23 inputs n-bit data, generates an input/output MAC frame, and outputs transmission data DT.

Next, the transmission data input section 15 inputs the transmission data D and the transmission control signal TCTL output from the data processing section 8, and based on the transmission control signal TCTL, transmits the transmission data D.
1 and also outputs a transmission instruction signal TS.

As a result, the transmission control section I6 of the communication station 11 sends a data request signal DR to the transmission data input section 15J2 based on the transmission instruction signal TS output from the transmission data human power section 15.
By outputting , transmission data D□ is input, and this transmission data D. transmission line 2 based on the data priority Pm of
Earn tokens that go around.

Then, the acquired token is changed into a frame start sequence, and a control field, an address field, an information field, a frame check sequence, and a frame end sequence are added thereto, and then outputted as a frame bit string FBA together with a selection signal SSEL.

Next, the frame bit string FBA output from the transmission control section 16 is selected by the transmission selection section 18, encoded by the encoding section 19, and then transmitted through the transmission section 20 as a signal SFT.

As a result, the signal SFT is transferred from the communication station I to the adjacent communication station I. The communication station l receives the signal SFT transferred via the transmission path 2 in the receiving unit 9, decodes it in the decoding unit lO, and then detects the timing signal STH in the received bit analysis unit 11 and determines the ring priority Pr. It also detects and generates the reservation priority R, and outputs the frame bit string FBA.

Next, the reception control # section 12 determines whether the input frame bit string FB^ is addressed to the own station. In this case, since it is not addressed to the local station, the received data Dr is not output.

Next, the bit delay 114 rewrites the bits while relaying the frame bit string FBA.

Since data is not being sent from the local station at the moment, the frame bit string FBA output from the bit delay unit 14 is selected in the transmission selection unit 18, encoded in the encoding unit 19, and then sent to the transmission unit 20. and then transmitted as a signal SFT.

As a result, the signal SFT is transferred from the communication station 1 to the adjacent communication station 13. Communication station 1. receives the signal SFT transferred via the transmission path 2 in the receiving section 9 and decodes it.
After decoding in 10, a received bit analysis unit 11 detects a timing signal STM, detects and generates a ring priority Pr and a reservation priority Rr, and outputs a frame bit string FBA.

Further, the reception control unit 12 determines whether the input frame bit string FBA is addressed to the local station. In this case, since the data is addressed to the local station, the received data DR addressed to the local station is output. Next, the received data output unit 13 inputs the received data DR,
It is output to the data processing section 8 based on the reception control signal RCTL output from the data processing section 8.

As a result, the input/output frame detection unit 21 of the communication station 13 inputs the received data DR output from the LAN connection unit 7, detects the input/output MAC frame from the received data D11, and uses the handshake line 22 to detect the input/output MAC frame. Peripheral devices 5. After confirming that a reception OK (ready) signal is output from the terminal, the transferred n-bit data is output.

As a result, communication station 1. The peripheral device 5 connected to the peripheral device 5. n-bit data transferred from is input.

“Effect of the Invention J As explained above, according to this invention, the ring type LA
The peripheral device can be easily connected to the N communication stations, and the peripheral device can easily transfer data with other communication stations without the burden of software.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a ring-type LAN according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of communication station l in FIG. 1, and FIG. 3 is a block diagram showing the configuration of a conventional ring-type LAN. It is a block diagram showing an example. ll-14... Communication station, 2... Transmission path, 5. ~54... Peripheral device, 7...L
AN connection section, 8... Data processing section, 21...
...Input/output frame detection section, 22゜24...
Handshake line, 23... Input/output frame generation unit.

Claims (1)

[Claims] A plurality of communication stations are connected in a ring shape by a transmission path, a predetermined address is assigned to each of the plurality of communication stations, a peripheral device is connected to each of the plurality of communication stations, and the plurality of communication stations are connected in a ring shape. In a ring-type LAN that transfers data that is input and output to each peripheral device between communication stations, the communication station has a data input and output terminal through which data is input and output, and a control signal that controls the input and output of the data. A ring-type LAN characterized in that the peripheral device has an interface that can be directly connected to the data input/output terminal and the control signal input/output terminal. .