JPH09162907A - Data transfer system of token pass system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize urgent data communication in a system where plural stations make communication by means of a token pass system. SOLUTION: In the case of a bus-type network 01, the type code CD of data which the station 1 obtaining the token TF1 is to transmit in addition to a code showing a token frame are stored in the FC part 22 of the token frame TF1, a destination address in a DA part 23 and a transmission source address in an SA part 24. The respective stations 1 are provided with token pass destination address tables 134 by individual codes CD, which are set for the respective stations. When urgent data communication is required during the communication of the token path with the code CD of regular data, a main station switches the code CD of the obtained token to the code of urgent data, sets the next station on the table 134, which corresponds to the urgent data code CD, to be the destination and transfers the token to it. An operation for transferring the token to the next station on the table, which corresponds to the code, after urgent data is transmitted by the station obtaining the token is sequentially repeated until the token is transferred to the main station at last.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a token as a system in which stations (also called stations) such as a computer, an FA controller and its input / output device connected to a network such as a LAN exchange data by a token path system. The present invention relates to a path type data transfer system.

[0002] In the drawings, the same reference numerals indicate the same or corresponding parts.

[0003]

2. Description of the Related Art Conventionally, the LAN access method of a system in which a plurality of stations (stations) connected to a LAN transfer data by a token path (also called token passing) method is IEEE802.4 or IEEE80.
There is a regulation of 2.5. In IEEE802.4,
The station that has acquired the token can transmit the frame according to a certain rule.

In IEEE802.5, a token is provided with a priority level, and when a station acquires a token, the station compares the priority level of the token signal with the level of the self-transmission request, and the level of the self-transmission request is higher. If you are going to send.

[0005]

However, when each station has data classified into several types and it is desired to quickly collect data of a particular type from a plurality of stations at a certain timing, the token as described above is used. In the pass method, another station unrelated to this data acquisition acquires a token on the way, and that station sends and receives data, so it takes time for the relevant station to acquire a token and send data. There is a problem.

Therefore, there is a system in which a priority level can be designated for data in order to avoid the influence of data exchange of other stations as much as possible, but other stations which transmit data at the same level have different data to be transmitted. If so, it will acquire the token and send it. Therefore, it is sufficient to specify whether transmission is possible or not depending on the type of data, but this is generally difficult.

Therefore, an object of the present invention is to provide a token path type data transfer system which can solve such a problem.

[0008]

In order to solve the above-mentioned problems, in the data transfer system according to claim 1, a main station (1-M or 1) connected to a network (01 or 01R).
RM) and one or more slave stations (1-P, 1-I, 1-
O, 1R-P, 1R-I, 1R-O, etc., in which each station communicates by the token path method, the token has a frame (TF1 or TF3) of (FC).
In addition to the information indicating that it is a token frame (in the section 22), there is information (CD, hereinafter referred to as data type code) that specifies the type of data to be transmitted by the station that has acquired this token, and each station has in advance. One or more of this data type code is assigned, and the main station can change the data type code of the acquired token at the time of sending the token according to the event that occurred (time-up of the timer, etc.). This token is acquired on condition that the data type code of the token matches the data type code assigned to the local station, and the data of the type specified by this data type code is transmitted.

According to the data transfer system of claim 2,
The system according to claim 1, wherein the network is configured as a bus type (01), and each station is assigned a data type code that is the same as the data type code assigned to its own station. Each station has an address table (token path destination address table 134) in which the address is registered, and each station passes the acquired token to another station registered in the address table corresponding to the data type code of this token.

According to the data transfer system of claim 3,
In the system according to claim 2, when the slave station joins the network, the slave station notifies the master station of all the data type codes (the data frame DF1 storing the data type code) allocated to the slave station together with the address of the slave station, Creates a new address table for each data type code including the addresses of slave stations participating in this network, and when sending a token having a data type code corresponding to this new address table, prior to this sending The data type code and the new address table (having the data frame DF2) are notified to at least each slave station related to the address table.

According to the data transfer system of claim 4,
In the system according to claim 2, when each station sends a token, all the data type codes assigned to that station (in the data section 27 in the form of token frame TF2) to that frame containing the address of the originating station. Is added as data information different from the original information of the token,
Among the stations that received the token frame at the time of sending this token, each station to which the same data type code as the data type code in the other data information added to this token frame is assigned The address table corresponding to the data type code including the station address is created.

According to the data transfer system of claim 5,
The system according to claim 1, wherein the network is configured as a bus type (01), and the master station sets a data type code of the acquired token every predetermined period (code value (B)).
It is assumed that the new token is transmitted by changing to a predetermined data type code, and each slave station determines the predetermined period based on the reception of the token frame when the master station transmits this new token. Own station timer (1
5) is started, and when a token having a data type code different from the predetermined data type code is acquired when the timer times out, the slave station next passes this token to the master station.

According to the data transfer system of claim 6,
The system according to claim 1, wherein the network is configured in a ring type (01R), and the master station sets a data type code of the acquired token every predetermined period (TB, etc.) (code value (B), etc.). It is assumed that this new token is transmitted by changing to a predetermined data type code, and at this time, immediately before the transmission of this new token (at the data frame DF3), at least the predetermined data type is addressed to all slave stations. Notify that you will send a token with a code,
Based on this notification, each slave station starts its own timer that measures the predetermined period, and when the timer times out, receives a token frame having a data type code different from the predetermined data type code. When I did
Try not to get the token.

According to the data transfer system of claim 7,
The system according to claim 6, wherein the predetermined period is
The master station notifies all slave stations together with the notification that the token having the predetermined data type code is transmitted.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) First, an embodiment of the invention relating to claims 1 and 2 will be described. Figure 1 shows the case where each station is connected to a network with a bus-type topology.
Station 1 and token frame T according to the present invention
The structural example of the format of F (TF1) is shown.

The token frame TF1 includes the SD unit 21,
FC unit 22, DA unit 23, SA unit 24, FCS unit 25,
The ED unit 26 is included. The SD section 21 indicates the beginning of the frame, and the FC section 22 indicates the type of frame. In addition, in this FC part 22 of the token frame, a token frame code as a frame type code indicating that the frame is a token frame (distinguished from a data frame), and the acquisition of the token by acquiring this token. A data type code CD indicating the type of data to be transmitted from the station is stored.

Next, the DA section 23 stores the address of the destination station of the token TF1, and the SA section 24 stores the address of its own station. The FCS unit 25 is a frame check sequence unit, and has a code for checking whether or not the frame is normally received. ED
The part 26 is a part indicating the end of the frame. It should be noted that the data frame transmitted by the acquisition of the token is usually formed in a format in which a data section 27 (see FIG. 3) for storing net data is inserted between the SA section 24 and the FCS section 25 of the token frame TF1. The FC section 22 of this data frame stores only the data frame code as the frame type code indicating that this frame is a data frame.

In this example, the station 1 is a master station (also called a main station) as shown in FIG.
1-M, a processor 1-P as a slave station (also referred to as a slave station), an input device 1-I, an output device 1-
The station 1 is generally composed of a CPU 11, a transmission control unit 12, a memory unit 13, a program memory unit 14, a timer 15, etc., as shown in FIG. The memory unit 13 also includes a transmission buffer 131, a reception buffer 132, a data memory unit 133, a token path destination address table 134, and the like.

Here, the transmission control unit 12 generates a transmission frame from the data in the transmission buffer 131 of the memory unit 13 when the token is acquired, modulates the transmission frame, and transmits it on the network. When a frame is received, it is demodulated, the data is transferred to the reception buffer 132, and it is checked whether the frame is a normal frame. The token path destination address table 134 of the memory unit 13 is a table in which the addresses of the stations that are the destinations of the tokens TF1 sent by the own station are arranged in the order in which the tokens are sent, and indicate the type of data that is sent by acquiring the tokens. It is provided for each of the above-mentioned data type codes CD. The data type code of the data transmitted by the station 1 is preset in the station 1. The last address of this token path destination address table 134 is the master station.
At least the master station 1-M has a token path destination address table 134 corresponding to all data type codes CD. The CPU 11 performs processing according to a program stored in the program memory unit 14 and manages transmission / reception data. That is, the frame type is checked such as whether the frame is a token frame or a data frame, and if it is a normal data frame, whether it is a frame addressed to its own station, that is, the data is Memory unit 133
To determine whether to transfer to.

In the case of the present invention, another master station 1
In -M, when the CPU 11 needs to change the data type code CD in the token, when the token frame TF1 addressed to the own station is received, the data type code of the FC unit 22 of the token frame TF1 newly transmitted. And the DA unit 23 to the address of the next station obtained by referring to the token path destination address table 134 corresponding to the changed data type code CD, and the SA unit 24 to the address of its own station. Then, the changed token TF1 is transmitted to the next station.

In the station 1 which has received this token TF1, the FC section 22 of the token TF1 is received.
Of the next station, which is obtained by referring to the token path destination address table 134 corresponding to this data type code CD of its own station, after transmitting the data corresponding to the data type code CD of Address and the SA section 24 to the address of its own station, and the changed token TF
Send 1 to the next station.

FIG. 2 shows one master station 1-M, a plurality of processors 1-P, and an input device 1-, respectively, as a station 1 having the above-described configuration in a bus type network 01.
An example of a token flow of a system in which I and output devices 1-O are connected to perform communication will be described. Here, FIG. 2A shows an example of a token flow at the time of communication of normal data (the value of the data type code CD is (A)), and FIG.
(C) receives the data of the input device 1-I (referred to as input data for convenience, the value of the data type code CD is (B)) at the beginning of the program executed by the processor 1-P. The data is fetched in the data memory unit 133, the program is executed, and the data of the processing result (referred to as output data for convenience, the value of the data type code CD thereof is (C)) is notified to the output device 1-O. An example of the flow of tokens in the case is shown.

In other words, in FIG. 2A, each station performs a process that does not require an emergency, and in this example, the processor 1-P performs a process that requires an emergency at regular time intervals in FIGS. 2B and 2C. Is to do. In FIG. 2A, the token pass is performed on the network 01 with the token TF1 in which the value of the data type code CD of the FC unit 22 is the code value (A) of the normal data, and all stations 1 sequentially issue the token TF1. After acquisition, normal data can be transmitted by a data frame in the acquired state. Then, communication is performed between each processor / input / output device as needed.

In this state, as shown in FIG. 2B, the master station 1-M sets the value of the data type code CD of the FC section 22 of the obtained token TF1 to (( B), the DA unit 23 as the address of the first station (input device) 1-I of the token path destination address table 134 corresponding to this data type code value (B), and the SA unit 24 as the own station 1-M. As an address, the token frame TF1 is transmitted to the input device 1-I.

The input device 1-I receiving this token frame TF1 receives the DA in the token frame TF1.
Since the address of the unit 23 matches the address of the own station and the data type code CD of the FC unit 22 and the data type code CD preset in the own station match, the token is acquired. On the other hand, processor 1-
Since the token destination address in the DA unit 23 in the token frame TF1 does not match the address of its own station, the P and the output device 1-O output the token frame T
No token is obtained even if F1 is received.

Token TF of data type code value (B)
The input device 1-I that has obtained 1 sends the data frame including the input data designated by the data type code value (B) to the network by the broadcast method in which the destination address of the DA unit 23 is not limited, and The address of the station to which the token is next passed is searched from the token path destination address table 134 corresponding to the code value (B), and the token is passed to that station.
At this time, each processor 1-P always receives the broadcast data frame from the input device 1-I, checks the address of the source input device of the SA section 24, and if the data is to be taken in, the data is received. Take in.

Thereafter, as shown in FIG. 2 (C), the master station (the final address of each token path destination address table 134 is the address of the master station 1-M) 1-M which has acquired the token again is shown in FIG. Two
Similar to the case of (B), next, the value of the data type code CD of the token TF1 is set to (C), and for the head station (processor) 1-P of the token path destination address table 134 corresponding to this data type code, To send a token frame. The processor 1-P, which has received the token TF1 having the data type code value (C), includes the output data as the processing result of the data previously received from the input device 1-I, and sets the DA unit 23 to the corresponding output device 1-O. The address of the station to which the token is next passed is searched from the token path destination address table 134 corresponding to the data type code value (C) while transmitting the data frame having the address of No. Pass the token to P.

After that, the master station 1-M that has acquired the token again sets the value of the data type code CD of the token to (A) again, and performs the normal data transmission / reception shown in FIG. 2 (A). By receiving the token frame TF1 having the data type code value (C), each processor 1-P recognizes that all the input data for this time is received from the input device 1-I, and the input data is received from the receiving buffer 132. The data is transferred to the memory unit 133 and the program processing of the processor is performed.

The transition from the state of FIG. 2 (A) to the state of FIG. 2 (B) is performed by the time-up of the internal timer of the master station in this example, but in addition to this, emergency data processing is performed. It is also possible to input a predetermined command to the master station 1-M at the time when the above is required. (Embodiment 2) Next, an embodiment of the invention according to claim 3 will be described. It is assumed that each station newly joining the bus-type network joins the network 01 in response to a call from the master station, for example, every predetermined time, and each new joining station 1 of FIG. A data frame having a structure such as DF (DF1), that is, all the data type codes CD set in the own station in the data section 27 in the frame are code values #
The master station 1-M is notified of the data frame stored from 1 to the code value #n.

The data portion 2 of the data frame DF1
The number NC in 7 is the total number of data type codes CD having code values # 1 to #n. As described above, the master station 1-M receives the data frame DF1 in which the data type code CD from each new participating station is stored, recognizes what data type code CD the source station has, and recognizes each data. A token path destination address table 134 for each type code CD is created.

The token path destination address table 134 at the center of FIG. 3 is the address table 134 corresponding to the data type code value #n thus created.
An example of the configuration will be described. After that, when the master station 1-M recognizes the need to change the value of the data type code CD of the token as described with reference to FIG. 2B by the event of the timer 15 or the like, the master station 1-M transmits the token frame TF1 addressed to itself. When received, this opportunity is used to create a data frame having a structure such as DF (DF2) in FIG.
That is, the data path 27 includes the token path destination address table 134 in which the address of the new participating station is included.
And a data type code (in this example, a code value #n) CD corresponding to the address table 134 and a data size in which the data size of the address table 134 is stored are created, and this data frame DF2 is set to all stations 1 To broadcast to.

Data frame D of this broadcast
Each station 1 receiving F2 checks whether or not the data type code notified in this data frame DF2 is set in its own station, and if it is set, the notified token path destination address table 1
Take in 34. After that, the master station 1-M
The value of the data type code CD of the token is changed to the code value to be changed, and the token frame TF1 is transmitted to the next station.

(Embodiment 3) Next, an embodiment of the invention according to claim 4 will be described. When each station 1 transmits a token frame when the system starts up, the token frame has the same frame configuration as the data frame DF1 in FIG. 3, in other words, the SA section 24 of the token frame TF1.
A token frame in which the same data section as the data section 27 of the data frame DF1 is provided between the FCS section 25 and the FCS section 25, and all the data type codes CD set in the own station are stored in this data section 27. TF
Similarly to the token frame TF1, (TF2) is transmitted to the next station as the destination.

However, this token frame TF2 is also intercepted by each station on the network other than the next station, and each station 1 knows what data type code CD the source station has and recognizes the data type code received. If there is the same code as the data type code CD set in the own station, the token path destination address table 134 of the own station can be created or changed as necessary.

After this, only the next station, that is, the station of the address stored in the DA section 23 of this token frame TF2 acquires this token TF2 and transmits data, and at the same time, the data type stored in the FC section 22. Similarly, the token frame TF2 is transmitted to the next station found from the token path destination address table 134 corresponding to the code CD.

(Embodiment 4) Next, another embodiment of the invention according to claims 1 and 2 will be described. Figure 4 shows each station 1R
Network with a ring-shaped topology
When connected to 1R (see FIG. 6), the token is a free token, and it is constantly traveling on the network,
A station 1R and a format example of a format of a token frame TF (TF3) according to the present invention are shown. The token frame TF3 has an SD section 21, an FC section 22, and an FCS.
The token frame TF1 of FIG. 1 does not include the DA unit 23 and the SA unit 24.
The contents of the SD unit 21, the FC unit 22, the FCS unit 25, and the ED unit 26 are the same as the token frame TF1.

Further, in the station 1R, FIG.
The token path destination address table 134 for station 1 is omitted, and the transmission control unit is replaced with 12R. FIG. 5 shows a configuration of a main part of the transmission control unit 12R. That is, the transmission control unit 12R creates a transmission data frame from the data of the transmission buffer 131 when the token TF3 is acquired, modulates the data frame through the parallel / serial conversion / modulation unit 121, and transmits the modulated data frame on the network 01R. When a frame is received, it is demodulated via the serial / parallel conversion / demodulation unit 122, and the frame is analyzed via the frame analysis unit 123. That is, the frame type check is performed to determine whether the frame is the token frame TF3 or the data frame, and whether the frame is a normal frame is recognized. If it is a data frame, it is checked whether it is a data frame addressed to the own station, and it is determined whether or not to transfer the data to the reception buffer 132.

Particularly in the present invention, the frame analysis unit 1
When the received frame is analyzed as the token frame TF3 in 23, the data type code CD in the FC unit 22 of this token frame TF3 is all the data set in the data type code storage register 124 of the own station. It is checked via the comparator 125 whether or not it matches any of the type codes CD. If they match, the buffer (# 1) 126 is enabled, the buffer (# 2) 127 is disabled, and the token TF3 is acquired. If they do not match, the buffer (# 1) 126 is disabled and the buffer is buffered. (# 2)
127 is enabled, and the token TF3 is allowed to flow downstream.

The CPU 11 notifies the transmission control unit 12R of the data type code CD of its own station according to the program stored in the program memory unit 14 and manages the data to be transmitted and received. FIG. 6 shows one master station 1R-M as the station 1R having the above-described configuration, a plurality of processors 1R-P, an input device 1R-I, and an output device 1 in the ring-type network 01R.
An example of a token flow of a system in which R-O is connected to perform communication is shown.

Here, FIG. 6A shows an example of a token flow of normal data (data type code value (A)), and in FIGS. 6B and 6C, the processor 1R-P executes it. The input data (data type code value (B)) of the input device 1R-I is received at the beginning of the program to be executed, the data is fetched into the data memory unit 133, the program is executed, and the output data of the processing result (data type code value (C)) Output device 1
An example of the flow of tokens when notifying to RO is shown.

In FIG. 6A, the token frame TF3 in which the value of the data type code CD of the FC unit 22 is the code value (A) of the normal data circulates on the network 01R, and all stations sequentially use the token TF3. , And normal data can be transmitted by the data frame in this acquisition state. Then, communication is performed between each processor / input / output device as needed.

In this state, as shown in FIG. 6B, the master station 1R-M sets the value of the data type code CD of the FC section 22 of the received token TF3 to (B) after a predetermined time by the timer 15 provided therein. And network 0
Stream on 1R. The input device 1R-I receiving this token frame TF3 receives the data type code CD in the token frame TF3 and the register 12 of its own station.
When the data type code CD set to 4 matches, the token TF3 is acquired. Conversely, processor 1R-P
Also, the output device 1R-O does not match the data type code in the token frame TF3 with the data type code of the own station. Therefore, even if the token frame TF3 is received, the token TF3 is not acquired and the data is sent downstream.

Token TF of data type code value (B)
The input device 1R-I that has acquired 3 sends the data frame having the input data (this format is the same as that of the bus type network 01) to the network 01R by broadcast, and also sends the token frame TF3 downstream. At this time, each processor 1R-P always temporarily stores the data from the input device 1R-I in the reception buffer 132. And the SA of the received data frame
The data of the input device 1R-I of the transmission source is checked from the section 24, and if the data is to be fetched, the input data is fetched.

After that, the master station 1R-M, which has acquired the token again after the token TF3 makes one round, is shown in FIG.
In (C), the data type code value of the token TF3 is set to (C), and the token frame T is displayed on the network 01R.
Flow F3. Token TF of data type code value (C)
The processor 1R-P that has received 3 receives the previous input device 1R
-A data frame including output data as a processing result of the data received from -I and having the DA unit 23 as an address of the corresponding output device 1R-O is transmitted to the corresponding output device 1R-O, and the token frame TF3 is provided downstream. Shed. After that, the token makes one round, and the master station 1R-M which has acquired the token TF3 again sets the value of the data type code CD of the token to (A) again, and performs the normal data transmission / reception of FIG. 6A. Receiving the token frame TF3 having the data type code value (C), each processor 1R-P recognizes that all the data from the input device 1R-I has been received, and the input data is received from the data buffer unit 133 by the receiving buffer 132. To perform program processing of the processor.

Also in FIG. 6, the transition from the state of FIG. 6 (A) to that of FIG. 6 (B) is performed by the master station 1R-M.
In addition to the time-up of the internal timer, the predetermined command may be input to the master station 1R-M. (Embodiment 5) Next, an embodiment of the invention according to claim 5 will be described. In FIG. 2, it is assumed that each station 1 has previously designated a cycle in which the master station 1-M changes the value of the data type code of the token TF1 to (B). Each station 1 has a timer 15, and when the master station 1-M receives the token frame TF1 transmitted with the data type code value as (B), the CPU
11 sets the timer 15 to a designated cycle and starts it.

When each station 1 recognizes the time-up of the timer 15 while exchanging data with the token of the data type code value (A) and acquires the token in that state, the DA unit 23 of the token TF1 The token TF1 is passed to the master station 1-M by unconditionally changing the destination address to the master station 1-M and transmitting.

(Embodiment 6) Next, an embodiment of the invention according to claim 6 will be described. In FIG. 6, the master station 1
RM is a token TF when a token is acquired in a fixed cycle.
Change the value of the data type code CD of 3 to (B),
At this time, the data frame DF3 as shown in FIG. 7 is broadcasted before transmitting the token with the changed data type code CD. The data part 27 of this data frame DF3 contains the value (B) of the data type code CD and the information of the cycle TB for changing the value of the data type code CD to (B). The station 1R takes out the cycle TB from the frame DF3, sets it in the timer 15, and starts it.

However, the period TB can be set and set in each station 1R in advance, and in that case, the period TB does not necessarily have to be stored in the data frame DF3. After that, the master station 1R-M changes the value of the data type code CD to (B) and the token frame TF3.
To the network 01R. FIG. 8 shows a configuration example of the main part of the transmission control unit 12R according to the present invention. In the figure, as compared with FIG. 5, a timer 15 is set up between the comparator 125 and the buffer (# 1) 126, and the buffer (# 2) 127 by a cycle TB, and a time-up signal (negative logic) of the timer 15 is added. The AND gate 128 which inputs the coincidence signal of the value (A) of the data type code CD of the comparator 125 and the coincidence signal of the value (B) or (C) of the data type code CD of the comparator 125 and the AND signal of the AND gate 128 An OR gate 129 for inputting the output signal is provided.

In FIG. 8, each station 1R suppresses the coincidence signal output of the value (A) of the data type code CD which is the output of the comparator 125 by the time-up of the timer 15, so that the value (A) at the time-up. The buffer (# 1) 126 is not enabled even when the token frame TF3 having the data type code CD of is received and the buffer (# 2) 127 is enabled, so that the data type code CD of the value (A) is obtained. Data type code CD of value (B) or (C) without acquiring possessed token TF3
Only the coincidence signal of
1) Since 126 is enabled, the token TF3 having the data type code CD of the value (B) or (C) can be obtained.

[0050]

According to the invention of claim 1, in the token frame flowing through the network, in addition to the information indicating that the frame is a token frame, the type of data to be transmitted by the acquisition of the token is specified. The master station has means for changing the data type code according to an event, and each station is set with the data type code for the data to be transmitted and receives the token frame. When the token is acquired, the means for transmitting the data of that type is provided only when the data type code on the token frame matches the data type code set in the token frame. When you want to send and receive data, you can exchange data by unnecessary data transfer. It is no longer time to extend.

According to the invention of claim 2, each station is provided with a token path destination address table in which the address of the station having the same data type code as the data type code set in its own station is registered. When a token frame with a data type code to be received is received, the token is passed to a station having the same data type code by referring to the address table, so the token is passed to an unnecessary station, Since it is not necessary to check the matching of the data type codes at that station, the time required for exchanging data is shortened.

According to the invention of claim 3, when the slave station (slave station) joins the network,
According to the invention of claim 4, the master station is notified of all the data type codes set therein, and the master station creates a necessary token path destination address table to notify each related slave station. , All data type codes set in itself are added to the token frame transmitted by the station at the time of system start-up as data information separate from the original information of the token. Since the station having the same data type code as the data type code creates the token path destination address table including the address of the originating station, it is not necessary to preset the station to which the token should be passed next.

According to the fifth and sixth aspects of the invention, the master station sets the value of the data type code of the token to (B) during the data exchange with the value of the data type code of the token (A). Since the station has means for monitoring the changing cycle and means for returning the token to the master station immediately when the time is up, the master station sets the value of the data type code of the token to (B It is possible to reduce the error of the cycle to be changed to (4) to flow to the network, in other words, to reduce the delay in the time of starting the processing of the data type code value (B) from the normal processing state.

[Brief description of the drawings]

FIG. 1 is a block diagram of a station and a token frame used in a bus type network as an embodiment of the invention according to claims 1 to 5.

FIG. 2 is a diagram showing the flow of tokens in the same bus network.

FIG. 3 is a configuration diagram of a data frame and a token frame as an embodiment of the invention according to claims 3 and 4.

FIG. 4 is a configuration diagram of a station and a token frame used in a ring network as an embodiment of the invention according to claims 1, 6 and 7.

FIG. 5 is a block diagram of the main part of the transmission control unit of the station.

FIG. 6 is a diagram showing a token flow in the ring network.

FIG. 7 is a configuration diagram of a cycle notification data frame as an embodiment of the invention according to claims 6 and 7;

FIG. 8 is a configuration diagram of a transmission control unit.

[Explanation of symbols]

01 bus type network 01R ring type network 1 (1-M, 1-P, 1-I, 1-O), 1R (1R-M, 1R-P, 1R-I, 1R-O) station 1-M, 1R-M master station 1-P, 1R-P processor 1-I, 1R-I input device 1-O, 1R-O output device 11 CPU 12, 12R transmission control unit 13 memory unit 14 program memory unit 15 timer TF ( TF1, TF2, TF3) Token frame DF (DF1, DF2, DF3) data frame 21 SD section 22 FC section 23 DA section 24 SA section 25 FCS section 26 ED section 27 data section NC number CD data type code SZ size TB cycle 121 Parallel / serial conversion / modulation unit 122 Serial / parallel conversion / demodulation unit 123 Frame analysis 124 data type code storing register 125 comparator 126 buffer # 1 127 buffer # 2 128 the AND gate 129 OR gate 131 transmit buffer 132 receive buffer 134 token passing destination address table

Claims (7)

[Claims] 1. A system comprising a master station connected to a network and one or more slave stations, wherein each station communicates by a token path method, wherein a token has, in addition to information indicating that the frame is a token frame, The station that acquired this token has information (hereinafter referred to as a data type code) that specifies the type of data to be transmitted, and each station is assigned one or more of this data type code in advance. The type code can be changed at the time of sending the token according to the event that occurred, and each station must use this token on condition that at least the data type code of the token matches the data type code assigned to itself. Token path characterized by acquiring and transmitting data of the type specified by this data type code Method data transfer system. 2. The system according to claim 1, wherein the network is configured in a bus type, and each station is assigned the same data type code as the data type code assigned to each station. Each station has an address table in which the address of each station is registered, and each station passes the acquired token to another station registered in the address table corresponding to the data type code of this token. system. 3. The system according to claim 2, wherein when the slave station joins the network, the slave station notifies the master station of all the data type codes assigned to the slave station together with the address of the slave station, and the master station uses this network. Created a new address table for each data type code including the address of the slave station that participated in, and when sending a token having a data type code corresponding to this new address table, prior to this sending, this data A token pass system data transfer system characterized by notifying at least each slave station related to this address table of a type code and a new address table. 4. The system according to claim 2, wherein when transmitting a token, each station separates all data type codes assigned to the frame to the frame including the address of the originating station from the original information of the token. Of each station that received the token frame at the time of sending this token, the same data type code as the data type code in the other data information added to this token frame was assigned. The token pass type data transfer system, wherein each station creates the address table corresponding to the data type code including the address of the transmitting station in the token frame. 5. The system according to claim 1, wherein the network is configured in a bus type, and the master station changes the data type code of the acquired token to a predetermined data type code every predetermined period. A new token shall be sent out, and each slave station shall start its own timer that measures the above-mentioned predetermined period based on the reception of the token frame at the time of sending out this new token from the master station. A token pass system data transfer system, wherein when a token having a data type code different from the predetermined data type code is acquired at the time of up, the slave station next passes the token to the master station. 6. The system according to claim 1, wherein the network is configured in a ring type, and the master station changes the data type code of the acquired token to a predetermined data type code every predetermined period, A new token shall be sent, and at this time, immediately before the sending of this new token, all slave stations shall be notified that at least a token having the above-mentioned predetermined data type code shall be sent, and each slave station shall receive this notification. Based on the above, each timer of its own station that counts the predetermined period is started, and when a frame of a token having a data type code different from the predetermined data type code is received at the time up of this timer, the token is A token-pass method data transfer system characterized by preventing acquisition. 7. The system according to claim 6, wherein the predetermined cycle is notified by the master station to all slave stations together with a notification that a token having the predetermined data type code is transmitted. Token pass data transfer system.