JPS6141246A - Station number setting system of packet communication network - Google Patents

Abstract

PURPOSE:To facilitate an easy control operation of station numbers by providing a means which transmits an initialization start command packet to a transmission line to a specific main station among plural stations and providing a packet counter which is reset after discriminating said command packet to a station excepting the main station together with transmission an answer packet to the transmission line in response to the command packet. CONSTITUTION:An initialization start packet is connected to a reception part RECV from a main station ST0 via a transmission line and the transmission/ reception separating parts TR of slave stations ST1-STN respectively. Then an answer packet is transmitted to the transmission line from a data processor PROS via a transmission part TRANS and the parts TR. A packet counter CONT is cleared to ''0'', and the detection signal of the answer packet which was sent onto a transmission line TL with no collision is connected to the CONT. Thus the number of detected packets are counted and this count value is connected to the part PROS as the number of own station.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a station number setting method for a packet communication network using a carrier detection multiple access method with collision detection and consisting of a plurality of stations connected on the same transmission path. In the carrier detection multiple access system with collision detection, each station detects a carrier wave when transmitting, and transmits when the transmission path is free. When the transmission path is busy, transmission is postponed until the transmission path becomes free. After the start of transmission, the transmission path is monitored for packet collisions, and if a collision occurs, after transmitting the collision enhancement bit, transmission is stopped and the transmission procedure is restarted after waiting for a time determined by a random number. This is the method of execution.

[Conventional technology]

FIG. 2 is a block diagram of packet communication using a carrier detection multiple access method with collision detection. FIG. 3 is a diagram showing the structure of the packet frame.

Multiple stations ST on the same transmission line TL as shown in Fig. 2
, ~ Carrier sensing multiple access system with collision detection (CSMA/CD, Carrier
SenseMultiple Access wit
In a packet communication network (Collision Detection), data is transferred in units of data groups called packets.

Each packet has a synchronization pattern of 5YN as shown in FIG.
C1 Receiving side station number DA, sending side station number SA, control information/
It consists of data DATA and check CRC.

Each station ST monitors the receiving station number DA of packets on the transmission path, and receives and processes packets whose station number matches the station number assigned to it. This station number is manually assigned a unique number to each station ST using a dip switch (DIP switch).

dual in 1ine package switch)
Or it was set by software switch etc.

[Problem that the invention seeks to solve]

However, with this method, it is necessary to manage station numbers on the same transmission path and to allocate and set new numbers to stations that increase one after another, which has the disadvantage that number management is difficult in large communication networks.

SUMMARY OF THE INVENTION The present invention is intended to solve these drawbacks, and aims to provide a station number setting method for a packet communication network that allows station numbers to be set easily and automatically.

[Means for solving problems]

The present invention includes one transmission path and a plurality of stations connected to the transmission path, and each of the plurality of stations includes a receiving section that receives a packet signal on the transmission path, and an output of the receiving section. a data processing unit connected to the data processing unit, a transmission unit connected to the output of the data processing unit and transmitting a packet signal onto the transmission path, and a network that monitors the transmission path and outputs a transmission path status signal to the transmission unit. In a packet communication network using a carrier detection multiple access method with collision detection and a monitoring unit, one main station determined from among the plurality of stations transmits an initialization setting start command packet to the transmission path. The stations other than the one main station among the plurality of stations are equipped with means for identifying the initialization setting start command packet, a packet counter that is reset by the identification output of this means, and a packet counter that is reset by the identification output of the means; means for transmitting a response packet in response to a configuration start command packet onto the transmission path, the network monitoring unit of the slave station including means for detecting a response packet transmitted without collision on the transmission path; The detection output of this means is connected to the count input of the packet counter, and the data processing section sets the counted value of the packet counter when the response packet can be transmitted from that station without collision as the number of that station. It is characterized in that it includes means for.

[Operation] In the present invention, the command monitoring unit of each slave station identifies the initialization setting start command received from the master station by the receiving unit, and sets the counted value of the packet counter to “0” using the identification signal from the command monitoring unit. . Clear the notes. When the initialization setting start command is received via the receiving section, the data processing section of each slave station transmits a response packet onto the transmission path via the transmitting section. The network monitoring section of each slave station detects that the response packets sent from each slave station are normally transmitted on the transmission path without collision, and counts the number of packets with a packet counter. In this way, when a response packet is transmitted normally without collision on the transmission path, the counted value of the packet counter at that time is inputted to the data processing unit as the station number of the station that transmitted the response packet. The number can be automatically set, which facilitates the management and operation of station numbers.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a station number setting device for a packet communication network according to an embodiment of the present invention. In Figure 1, the transmission line T
The packet from L is connected to the transmission/reception separation unit TR. The received packet separated by the transmission/reception separation unit TR is sent to the reception unit REC.
The data of the received packet from the receiving unit RECV is connected to the data processing unit PRO3. Further, a transmission packet is connected from the data processing unit PRO5 to the transmission/reception separation unit TR via the transmission unit TRANS. Transmission/reception packets between the transmission path TL and the transmission/reception separation section TR are branched and connected to the network monitoring section NET, and a transmission path status signal is connected from the network monitoring section NET to the transmission section TRANS.

Here, the feature of the present invention is the station number setting portion surrounded by a dashed line. That is, the main station ST.

The initialization setting start packet is sent to the transmission path and each slave station ST.
,-S? , the receiving unit RECV via the transmitting/receiving separation unit TR of
connected to. An initialization setting start command is connected from the receiving unit RECV to the data processing unit PRO5, and a response packet is transmitted from the data processing unit PRO5 to the transmission path via the transmitting unit TRANS and the transmission/reception separation unit TR.

An initialization setting start command is connected from the receiving unit RECV to the command monitoring unit COMMAND. Command monitoring section C
The initialization setting start command is identified by ND to 0MM, the identification signal is connected to the packet counter C0NT, and the packet counter C0NT is cleared to "0".

In addition, the network monitoring department NE of each station ST+ ~ STH
A detection signal of a response packet transmitted from T on the transmission path TL without collision is connected to a packet counter C0NT,
The number of packets detected is counted. Packet counter C0N
The count value when the response packet of the own station is transmitted from T without collision is connected to the data processing unit PROS as the station number of the own station.

The operation of the station number setting device for a packet communication network having such a configuration will be explained. In FIG. 1, packets from the transmission line TL are transferred to the data processing unit PRO3 of each station ST via the transmission/reception separation unit TR and the reception unit RECV. Also, the data from the receiving unit R1ICV is sent to the command monitoring unit C.
Transferred to OMMAND, command monitoring unit COMMAN
When D identifies the initialization setting start command, it clears the packet counter C0NT to "0". The response packet to the transmission path TL is transmitted from the data processing unit PRO8 via the transmission unit TRANS and the transmission/reception separation unit TR.

The transmission path TL is monitored by the network monitoring section NET, and a transmission path status signal is notified to the transmission section TRANS.

Also, when a response packet transferred without collision on the transmission path TL is detected, the packet counter C0NT is added to the count value by "1".
” is added.

Here, each station ST performs packet communication using a carrier detection multiple access method with collision detection. In other words, each station S
When T transmits, the transmitting unit TRANS monitors the transmission path status signal detected by the network monitoring unit NET, and performs transmission when the transmission path TL is in an empty state. Transmission line TL
When the transmission line TL is busy, transmission is postponed until the transmission line TL becomes free. After the start of transmission, the transmission path TL is monitored for packet collisions, and if a collision occurs, the transmission is stopped after transmitting a collision enhancement bit, and the procedure is to transmit again after waiting for a time determined by a random number. Execute.

In the packet communication network shown in Fig. 2, normally the main station ST
, there exists a station. This master station STo and other slave stations ST
, ~ST, when the packet communication network has not been initialized, each slave station S on the transmission path TL
Since the own station numbers have not yet been set for T, .about.STN, all normal packets transferred on the transmission path TL without collisions are received.

When the master station STo sends an initialization setting start command packet several times to any slave station using an arbitrary sending station number to initialize the packet communication network, each slave station ST, ~ST, on the transmission path TL, receives this initialization setting start command packet, clears the packet counter C0NT to "0", waits for the predetermined time tw shown by the following formula (1), and then transmits the arbitrary receiving side station number on the packet communication network. With DA and any sending station number SA, the following formula (2)
Sends a response packet with data length indicated by .

tt+ = 2X (transmission time of transmission line TL) 10 stations ST
Maximum value of initialization setting start command processing time
−・・−・−・−(1) L=
(2X (Transmission time of transmission path TL) Busy reinforcement time of live transmission path) / (Transmission time of 1 bit)
−1−−−−−−(21 Also, each slave station ST, ~
When the ST receives the initialization setting start command packet and is able to send a response packet without collision, the main station STO
The transmission of packets is stopped until an initialization setting end command packet is received from , and the counted value of the packet counter C0NT when transmission is normally completed without collision is set as the station number of the own station.

When receiving the initialization setting start command packet from the master station ST, the packet counter C0NT of each slave station ST+~STN becomes "0", and each slave station "TI""STN responds to the initialization setting start command packet. When a packet is transmitted, the packet is transmitted to each slave ST without causing a collision.
+-3TH packets are successfully transmitted one by one.

FIG. 4 is a diagram showing the setting operation of the station number setting device for a packet communication network according to the present invention. In state I, the master station STO communicates with each slave station S.
An initialization setting start command packet has just been sent to T and -3TN. At this time, each slave station ST.

The packet counter C0NT of ~STN is undefined and is reset to "0" when the initialization setting start command packet is received.

In case J1gn, after receiving the initialization setting start command packet, all the slave stations 5TI-5TN sent it all at once, and the response packets of the slave stations 5TI-3TN collided with each other, and both slave stations ST and -3T received the message due to the collision. Start retransmission operation.

In state ■, one slave station STx retransmits the response packet by retransmission operation, and each slave station STx by the initialization setting start command
This is the place where the first response packet that was completed without collision after the start of transmission of I to ST was transmitted.

Slave station STX has packet counter C0NT count value “0”
and ``1'' is added to rlJ, which is set as the own station number.

In addition, the packet counter C of each slave station ST, ~STH
The count value of 0NT becomes "1" by adding "1".

State (2) is a state where, following state (2), the slave station ST has completed transmission without any collision. Slave station STv has packet counter C0N
Add "1" to T's count value "1" and set "2" as the own station number. Further, the count value of the packet counter C0NT of each slave station ST and -3TN is added with "1" and becomes "2".

By performing the same procedure thereafter, each slave station ST.

~STN can each be set with a unique station number.

Furthermore, the master station STO monitors the signal on the transmission path TL, and if the response packet next to the response packet transmitted immediately before is not transmitted by the predetermined time 1E, each slave station ST
~STN assumes that the station number setting for its own station has been completed,
Sends an initialization setting end command packet and then shifts to normal data transfer mode. Each slave station ST+ ”'ST
When N also receives the initialization setting end command packet, it shifts to normal data transfer mode.

〔Effect of the invention〕

As explained above, the present invention identifies an initialization setting start command packet, transmits a response packet, and sequentially assigns station numbers starting from the station that successfully completed transmission without colliding with response packets from other stations on the transmission path. This has the advantage of being able to be automatically assigned and facilitating the management and operation of station numbers. This invention is extremely effective when applied to local area networks.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a station number setting device for a packet communication network according to an embodiment of the present invention. FIG. 2 is a block diagram of a network communication network using a carrier detection multiple access method with collision detection. FIG. 3 is a diagram showing the structure of the packet frame. FIG. 4 is a diagram showing the setting operation of the station number setting device for a packet communication network according to the present invention. COMMAND...Command monitoring section, C0NT...
Packet counter, NET...network monitoring section,
PRO3...data processing section, RECV...receiving section,
STO...Main station, ST, ~STN...Slave station, TL.
...Transmission path, TR...Transmission/reception separation unit, TRANS...
・Transmitter, DA...receiving station number, DAT^...control information/data, CRC...check data, sto...
Receiving side station number, 5YNC...Synchronization pattern. , also 2 figures

Claims (1)

[Claims] (1) One transmission path and a plurality of stations connected to this transmission path, each of the plurality of stations having a receiving section that receives the packet signal of the transmission path, and an output of this receiving section. a connected data processing section, a transmitting section connected to the output of the data processing section and transmitting a packet signal onto the transmission path, and a network monitor that monitors the transmission path and outputs a transmission path status signal to the transmission section. In a carrier detection multiple access packet communication network with collision detection, one main station determined from among the plurality of stations has means for transmitting an initialization setting start command packet to the transmission path. The stations other than the one master station among the plurality of stations (hereinafter referred to as "slave stations") have a means for identifying the initialization setting start command packet, and a means for identifying the initialization setting start command packet, and a means for being reset by the identification output of this means. a packet counter; and means for transmitting a response packet to the transmission path in response to the initialization setting start command packet; The detection output of the means is connected to the count input of the packet counter, and the data processing section is configured to detect the count value of the packet counter when the response packet can be transmitted from the station without collision. A station number setting method for a packet communication network, characterized in that the method includes means for setting the number as the number of the station.