JP3501650B2 - Programmable controller network system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
Used for communication between controllers (hereinafter referred to as PC)
For programmable controller network systems
Related to the network unit. [0002] 2. Description of the Related Art In various production and assembly lines,
PCs can communicate with each other via a network cable
Building a PC network system by connecting
Has been done a lot. PC network systems include:
One PC performs data communication with another node (other PC)
Mainly due to cyclic transmission and transient
Two transmission modes of transmission are provided. [0003] Cyclic transmission and transient transmission are
These are communication functions supported by the PC,
Rick transmission sets each station's own transmission range (for its own station).
Reception range is outside transmission range), each station is cyclic
To all stations using broadcast method
(Broadcast). In cyclic transmission, you
The user does not need to be aware of communication,
Simply transmit the content you want to convey to other stations.
Can be. Processes between PCs in transient transmission
Request frame and response frame round trip for every request
Communication form. [0004] In cyclic transmission and transient transmission,
The fundamental difference is the constant nature of the transmission process and the user program
In the interface, local memory without being aware of communication
Content that you want to convey and create with the image of writing data to
Always transmit data in the pair n (the former) or use command
Thailand where a request was made for the content to be created and conveyed
Or one-on-one transmission (the latter)
You. Next, a conventional example will be described with reference to FIGS.
I will tell. FIG. 7 shows a conventional network unit 1001 and
A PC network system composed of the PC body 1002
1 shows a system configuration. Network unit 1 of each station
001 are mutually connected by the network cable 1003.
Connected and can exchange data with each other. P
The user program on the C main unit 1002 is
The user program on the PC of the other station via the unit 1001
Exchange data with gram. Each network unit
Station numbers 1 to 4 are assigned to 1001. Network
No duplication of the station number is allowed in the security system. The station number is
If they overlap, the transmitted data is sent to either station.
This is because it is not possible to determine whether to hand it. Data communication
Is performed based on this station number. The station number is one network
Work systems need to be unique. FIG. 8 shows a network system as described above.
2 shows the state of transmission control in. Network
The polling method is used as a transmission control method in the system.
Method, CSMA / CD method, token method, etc.
Is already known. In the example shown in FIG.
This is an explanatory diagram using the Kun method. [0007] The token system is a transmission method called a token.
Credentials circulated on the network and captured tokens
This is a control method in which only stations transmit data, and talk
Stations that do not have a token cannot transmit and have a token.
Can receive data transmitted from the station. G
Data transmission in a kun-type network system
Is, as shown in FIG.
Capture of tokens, transmission of data from token holders, token storage
Receiving data from the organization, releasing tokens → circulating tokens
It is performed by repeating times. [0008] In the cyclic transmission, each station transmits its own transmission range.
Set the reception area (except for the transmission range of your own station will be the reception range),
Each station cyclically broadcasts the contents of its own transmission range
Broadcast to all stations simultaneously by the cast method.
Indicates the transmission data (transmitting station), and "O" indicates the reception data.
(Reception station). Cyclic transmission is always
Since the message is transmitted by the broadcast method, there is no response message.
Does not exist. Data transmission → Data reception only in one direction
is there. [0009] Transient transmission is processed between PCs
Request frame and response frame round trip for every request
In FIG. 8, the station number 1 is the
Transit to station number 3 at the same time
Sends a request for the token, and
Send a transit response at the moment. Transient
Responses are essential in transmission. Transient transmission
As described in the protocol (communication protocol)
Is a simple two-way communication between request and response.
However, at the user program level,
Data exchange, the read request is
The response of read data is written for a write request.
A write response indicating completion of writing is required.
You. FIG. 9 shows transmission in a network system.
This shows the frame format. This frame
"F" indicates the start and end of a frame
"DA" is the destination address, and "SA" is the
The source address “C” is a control indicating the contents of the frame.
Roll field, "I" is information part of frame (data
Itself), “FCS” is the frame inspection sequence
You. For example, if “C” is “0”, cyclic
Transmission data, if "C" is "1", transient
This is transmission data. FIG. 10 shows a PC network.CisAgainst the system
9 shows a state when a new station 5 is added. To FA
System currently in operation
Then, a new PC may be added as it is. Especially raw
The more products that you produce, the more products you have
Lines are added frequently. With the production line running,
Expanding the system is the most efficient
Utilization rate, and for the user,
The profit and loss will be small. I.e. stations online
Additional, online debugging is of interest to users
It is one of the strong items. FIG. 11 shows the transmission control after the station 5 is added.
Shows a child. Cyclic transmission is a user program
Network unit 1001 regardless of the
Therefore, station 5 holds the token because it is performed automatically.
Then, the data is sent automatically. FIG. 12 shows a user program of the added station 5.
Is issuing a transient request.
You. User program on the PC 1002 of the added station
Triggering the transmission of a transient request in the
A transient request is issued to station 1 at the
Has been done. When the station 1 holds the token
A transient response is returned to the station 5. I mentioned earlier
Thus, a response is essential in transient transmission. Considering this from the viewpoint of the user's system
View. The system cannot run on a single PC
In addition, multiple PCs must cooperate with each other
Controlling. There are various ways to think about this cooperation.
However, by reading each other's data,
Controls the behavior of the own system according to the state of the system
Or write your own data to the other party to
Status is notified to the remote system and the status of the remote system is notified to the remote system.
Coordination in the form of control over
Is common. In order to cooperate, the request sent
Response is essential. The response here is read
The request is read data and the write request
Indicates that the writing was completed normally
), Or a write error was completed (write
Indicating that the operation was not performed normally). Also, there is always a request target station.
There is no guarantee that The system is not state-invariant;
The station to which the request was sent was turned off due to tenancy, etc.
May not have subscribed to the network system
obtain. Therefore, the transmission target station is in an abnormal state (the transmission target
Is still one of the abnormal conditions), abnormal response
Can be returned to the user program by transient transmission.
Is one of the important functions. This is because the system
Coordination with a dead station is not possible
Not be able to obtain read data or write completion
Is not possible). When the production line is in normal online operation
If the station 5 is cyclic transmission and transient transmission
Has no problem, but station 5 is a new member
Station, that is, the station being debugged, and the user
There is no guarantee that the program will transmit data normally. others
User makes one copy of the running system
Debug the user program of station 5 or
Between the start of transmission and the transient request
By setting the offline switch to
Even if a signal enters, the transmission process is not actually performed.
To debug user programs. However, the former is costly for the user.
The latter is the cause of the
Transmission processing (between the PC and the network unit)
Debugging is not performed for
There is a shortcoming. FIG. 14 shows the network unit 1001.
Function blocks for transmission / reception processing and communication status creation processing for each station
Is explained. User program reported to other stations
Data is transmitted to the outside through transmission processing A,
The data is passed to the user program via the receiving process B
You. When receiving data, the frame format shown in FIG.
Because the frame is sent and received based on the
The source station number can be determined by referring to “SA” of FIG. The result
In each station communication status creation process C using the result, each station is normal
To determine if they are communicating with The communication situation is
“0” indicates that communication is being performed, and “1” indicates that communication has not been performed. FIG. 15 shows the network unit 1001.
The schematic flow of the transmission / reception process and the communication status creation process of each station is shown.
are doing. First, check if there is any received data (step
S101) If there is received data (step S101: Yes)
), According to “SA” in the received frame format.
The source station number is checked (step S102). Next
Then, the communication status of the source station number is updated (step S10).
3), transfer the received data to the user program
(Step S104). If there is no received data (step S101)
(No), confirm the presence or absence of transmission data (step S10)
5) If there is no transmission data (step S105: No)
), And complete the process. Even if there is data to send (step
Step S105 affirmative), transmission was not possible without a token
Then, the presence or absence of a token is confirmed (step S106).
If there is no token (No at Step S106), talk
This process is completed because it is necessary to acquire the toe
If it is determined that there is a crack (Yes at step S106)
Data) from the user program and send
Is performed (step S107). At first glance, this flow transmits data.
It seems that there is no timing, but your station holds the token.
Other stations transmit data at the timing they have
Since there is no
Exists. That is, if this flow is executed,
Data transmission is possible. FIG. 16 is a schematic diagram of the transient transmission process.
Shows low. In the transient transmission process,
The token is checked (step S111).
If there is a token (Yes at step S111), the user
Data from the datagram and perform transmission processing (step
S112). If there is no token (step S111
Denial), because it is necessary to acquire a token,
Complete. FIG. 17 shows that the own system transmits a request and responds.
Until the user program, PC and station are received
Indicates whether data is exchanged at the timing
are doing. When the user program makes a transmission request, the PC
Passes the transmission request to the receiving station, and the station requests on the network
Send a message. As a result, the request message is transmitted to the transmission target station
Is done. The message includes the destination address DA as described above.
And the source address SA are clearly specified.
Network can transmit messages to the target station.
You. The message arriving at the target station is passed to the PC.
Is passed from the PC to the user program of the target station.
You. The target station processes the request, creates a response, and responds
Send When creating a response, the destination address DA of the message
In order to replace the source address SA, the response is
It will be transmitted to the bureau. After that, send request
Request source user program by the same procedure as
Is passed the response. [0025] As described in the section of the prior art,
In other words, in the production and assembly line at FA,
Adding new PCs to existing systems
Products that have a large lineup
The more production lines are added, the more online
Stations added, online user program debugging
Is one of the items of interest to the user. However, in a conventional network system,
As described in the transmission control method,
When the token is captured, transmission starts immediately.
Stations that are unknown to existing production lines.
Is equivalent to unknown data coming from
There is a concern that the control of the production line will be adversely affected. this child
And the user program transmission start and
By switching offline during the request
Even if a transmission start signal is received, transmission processing is actually performed.
Debug the user program to prevent
Offline switch after debug completionToDelete
Is the interface between the PC and the network unit.
Debugging is performed for transmission processing related to
The quality of debugging
Add / remove offline switches in the program
Such a troublesome work is required. In addition, one copy of the running system is created.
Debugging the user program of the additional station
To impose a large cost burden on system construction users
become. The present invention solves the above-mentioned problems.
Off in the user program
Troublesome work such as adding and deleting line switches and operation
Without having to make a copy of the system
Active FA system and user program after debugging is completed
Accurate online data without affecting the
Programmable controller net that enables bags
To get a network unit for the work system
The purpose is. [0029] In order to achieve the above object,
The inventionNow, a network with a unique station number
Network units, each with its own
Controller via each network unit.
Station that has the transmission right by connecting to the
Source address, destination address, cyclic transmission
And transient transmission
Frame signal including troll field and data
, The station that has obtained the transmission right
The frame signal is transmitted to the station in a broadcast system.
And the station that has the right to transmit is another
Transmit the frame signal as a request frame signal to the station
And the station receiving the request frame signal transmits
At the time of obtaining the right, the
And transmit to the source station
To run on multiple programmable controllers.
Controllers that control the controlled system
In the programmable controller network system
Each network attached to each programmable controller.
The network unit determines whether or not its own station is in debug mode.
A mode storage unit that stores a mode signal that specifies
The frame signal transmitted over the network cable.
Each station is communicating based on the source address in the signal
Or communication status information indicating whether communication has not been performed
The station communication status creation processing unit and the mode signal
If the code is specified, the cyclic transmission
When performing such transmission and reception, only data reception is performed and the transmission is performed.
Data transmission is not performed even if the right is acquired.
Request for the transient transmission from the
When a frame signal is received,
Based on the communication status information from the
The station corresponding to the destination address is communicating or not communicating.
Determine whether communication is in progress, and if communication is in progress, receive
The response frame signal corresponding to the requested frame signal
If no communication has been performed, an abnormal response frame signal
Execute the process to return to the station programmable controller.
Transmission and reception control means. [0030] [0031] [0032] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Programmable controller network system according to Ming
The embodiment of the network unit for the system is explained in detail.
I will tell. In addition, in the embodiment of the present invention described below,
Here, the same components as those of the above-described conventional example
The same reference numerals are given to the same reference numerals, and the description is omitted.
You. Embodiment 1 Figure 1 shows an existing network
Shows a system configuration in which stations 5 and 6 are added to the
ing. The PCs with station numbers 1 to 4 are existing PCs, and
6 is debugging the user program (hereinafter called “debugging”).
PC). FIG. 2 shows a network unit according to the present invention.
Function of the transmission / reception processing at step 11 and the communication status creation processing at each station.
Describes locking. This network unit
G11 actually transmits the data to the transmission process A to the outside
In addition to the actual transmission processing section Aa, the operation of its own station (onlineInnMo
Mode that stores the
Mode storage unit Ab and the mode storage unit Ab
A mode determination processing unit Ac for determining the content is added.
“0” is online for the contents of the mode storage section Ab
Indicates that "1" is the debug mode. In this mode, a user size is set by a switch or the like.
The mode is switched by mode, and the existing PC (existing station) is
PC (additional station) in debug mode is in debug mode
Is set to In online mode, the online mode
Broadcast the data transmitted from stations 1 to 4 to all stations.
And perform normal data communication. In contrast,
In back mode, only receives data from existing stations
Even if you have a token (data transmission right), you can send data
Release the token without believing. FIG. 3 shows a network unit according to the present invention.
In a PC network system using
The state of the click transmission communication is shown. Minute from Figure 3
Station numbers 1 to 4 for which the online mode is set
Existing stations are onlineDo stationSent from 1-4
Broadcast data to all stations
Rick transmission communication. In contrast, the debug mode
The additional stations with station numbers 5 and 6 are the data from the existing stations.
Only, and send data even if you have a token.
Release tokens without having to. Communication status of each station of the network unit 11
The creation processing C is performed in the same manner as in the related art.
Each station is communicating normally by referring to "SA" in the
It is determined whether or not. The communication status is “0”,
“1” indicates that communication has not been carried out, and the communication status information Ci of each station is provided.
Hold. The network unit 11 performs the return processing
Part DButHas been added. The return processing unit D
In the event transmission, if the own station is in the debug mode,
The contents of the mode discrimination processing performed by the
Receive and transmit based on the content of each station communication status information Ci
Determine the presence or absence of a transmission target station according to the communication status of the target station,
Create a normal response or abnormal response and perform loopback processing
U. Next, referring to FIG.
Overview of transmission / reception processing of unit 11 and communication status creation processing of each station
The flow will be described. Reception processing steps S101 to S101
Step S104 is the same as the conventional one, and
Data (step S101), and the received data
If there is (Yes at Step S101), the received frame
Check the source station number by "SA" in the format
(Step S102). Next, the communication status of the source station number
Is updated (step S103), and the received data is
The program is transferred to the program (step S104). If there is transmission data (step S1)
05 affirmative), reads mode information from mode storage section Ab
The mode determination of the own station is performed by the mode determination processing unit Ac.
Perform (step S108). In this mode judgment,
If the mode of the own station is the online mode (step S
108 affirmation), secure the token as before
As soon as data is received from the user program and transmitted.
(Steps S106 and S107). This
On the other hand, if your mode is debug mode,
(Step S108 No), without transmitting data
This process is completed. That is, as long as the station is in the debug mode,
Receive data from other stations, but transmit own station data
Never. Therefore, it affects all other stations in terms of data.
New without affecting the operating FA system
The user program of the station can be debugged. FIG. 5 shows a network unit according to the present invention.
In a PC network system using
The state of the Langent transmission communication is shown. online
The PC of station number 1, which is the existing station with the mode set, is
Like the one, the station number at the timing of holding the token
Issued a transient request to 4 and received the request number
The PC of No. 4 responds to the station number 1 when the token is held.
And return a transient response. Station number 5 of the newly added station
The PC at station No. 6 responds to the
Because it is in debug mode even if you have a kun,
Return processing is performed within the own station. Next, referring to FIG.
About the schematic flow of the transient transmission process of
Will be explained. First, the mode information is stored from the mode storage unit Ab.
Read and mode of own station by mode discrimination processing unit Ac
A determination is made (step S113). Your station mode is on
If the mode is the line mode (Yes at step S113),
Confirm the existence of the token (step S
111), if there is a token (step S111: yes)
Data) from the user program and send
Is performed (step S112). On the other hand, the mode of the own station is the debug mode.
If the answer is NO (step S113: No), each station communication status
The communication status information Ci of each station in the process C is read out (step
Step S114), the corresponding station (transmission
(E.g., the elephant station) is performing communication (step
S115). This determination is based on the contents of each station communication status information Ci.
This is performed by referring to the communication status information Ci of each station.
If the corresponding station bit is "0", the corresponding station performs communication.
If the corresponding station bit is “1”, the corresponding station
Not implemented yet. If communication is in progress (step S115: Yes)
), Create a normal response assuming that the target station exists.
(Step S116), a return processing is performed (Step S116).
S118). When the authority determines that communication is not in progress
(Yes at step S115), there is no transmission target station.
And creates an abnormal response (step S117)
A return process is performed (step S118). That is,
Mode station requests transient by user program
If a communication error occurs, the communication status of the other station
Create a response in your own station using the
U. As a result, the user program can be
Debug mode even if a transient request occurs
Since the station does not transmit data, the existing line is
Has no effect on the data mode station. It should be noted that a normal response also needs an abnormal response.
Is omitted because it is the same as the conventional example. In addition, the target station
If communication is not implemented, there is no response from the target station
It is not necessary to return a response inside the station
It is obvious. The network unit 11 is the PC body 10
02 and receives a transient request
Network unit to transfer the client response.
Data of the interface between the
Backing is possible enough. [0048] As will be understood from the above description,
By the lightIf the controlled system is actually running,
Stations and the system to be controlled without affecting the
Programmable controller newly added to the work
About cyclic transmission and transient transmission
Debugging of the program related to
The effect is that it can be executed in a state closer to
I do. [0049] [0050]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram showing an example of a programmable controller network system using a network unit according to the present invention. FIG. 2 is a block diagram showing functional blocks of a transmission / reception process and a communication status creation process of each station in a network unit for a programmable controller network system according to the present invention. FIG. 3 is a timing chart showing a state of cyclic transmission communication in a PC network system using a network unit according to the present invention. FIG. 4 is a schematic flowchart of a transmission / reception process by a network unit and a communication status creation process of each station according to the present invention. FIG. 5 is a timing chart showing a state of transient transmission communication in a PC network system using a network unit according to the present invention. FIG. 6 is a schematic flowchart of a transient transmission process of a network unit according to the present invention. FIG. 7 shows a conventional network unit P
1 is a system configuration diagram illustrating an example of a C network system. FIG. 8 is a timing chart showing a state of transmission control in a conventional PC network system. FIG. 9 is a frame format diagram showing a frame format transmitted in the PC network system. FIG. 10 is a system configuration diagram showing a situation when a new station is added to the PC network system. FIG. 11 is a timing chart showing a state of transmission control after a station is added in the conventional example. FIG. 12 is a timing chart showing a state in which a user program of an added station issues a transient request in a conventional example. FIG. 13 is a ladder diagram showing a transmission section of a user program at the time of debugging in a conventional example. FIG. 14 is a block diagram showing functional blocks of a conventional transmission / reception process of a network unit and a communication status creation process of each station. FIG. 15 is a schematic flowchart of a conventional transmission / reception process by a network unit and a communication status creation process of each station. FIG. 16 is a schematic flowchart of a conventional transient transmission process performed by a network unit. FIG. 17 is a timing chart showing the timing of data exchange between the user program, the PC, and the station until the own system transmits a request and receives a response. [Description of Signs] 11 Network unit, 1002 PC main unit (programmable controller main unit), 1003 network cable, Aa transmission actual processing unit, Ab mode storage unit, Ac mode determination processing unit, D return processing unit.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-3-156613 (JP, A) JP-A-6-3388893 (JP, A) JP-A-5-284167 (JP, A) JP-A-59-1984 216211 (JP, A) JP-A-9-223039 (JP, A) JP-A-8-153019 (JP, A) JP-A-3-204057 (JP, A) JP-A-62-248060 (JP, A) Japanese Patent Application Laid-Open No. Hei 2-236739 (JP, A) Akira Sugiyama, Toshiya Takahashi, Hoho Fukatsu, Tatsuo Ito, Takashi Watanabe, Akikatsu Kabe, FA network "MELSECNET / 10" and various open networks, Mitsubishi Electric Corporation Bulletin, Japan, Mitsubishi Electric Gihosha, December 25, 1994, Vol. 68, No. 12, pp. 98-104, ISSN 0369-2302, Shun Ota, Multi-vendor network promoting CC-Link control and information, Instrumentation, Japan, Industrial Technology, April 1, 1997, Vol. . 40, No. 4, p. 49-54, ISSN 0368-5780 (58) Fields investigated (Int. Cl. ⁷ , DB name) G06F 11/28 G05B 19/05 G05B 23/02

Claims (1)

(57) [Claims] [Claim 1] A network unit provided with a unique station number
Multiple programmable controllers each with a knit
Network card via each network unit.
Connected to the network and the station that has obtained the transmission right transmits to other stations.
Source address, destination address, cyclic transmission and
A control that indicates whether the transmission is a Langent transmission
Transmits frame signals including fields and data
By doing so, the station that obtained the transmission right
A server for transmitting the frame signal by a broadcast method.
The station that received the transmission right before the other station
The frame signal is transmitted as a request frame signal.
The station that received the request frame signal obtained the transmission right
At the time, the frame signal is transmitted as a response frame signal
Transient transmission to the original station is performed at each station.
Allows multiple programmable controllers to interact with each other.
Programmer who controls controlled system by emphasizing
In the controller network system, each network attached to each programmable controller
The network unit transmits a mode signal that specifies whether or not the own station is in the debug mode.
A mode storage unit for storing a signal, and the frame transmitted on the network cable.
Each station is communicating based on the source address in the signal.
Create communication status information indicating whether or not communication has been performed
Each station communication status creation processing unit, and when the mode signal specifies the debug mode
When transmitting and receiving the cyclic transmission,
Even if only the data is received and the transmission right is acquired, the data is transmitted.
Communication from the local station programmable controller.
When a request frame signal for transient transmission is received
Indicates the communication status information from the communication status
Station corresponding to the destination address in the request frame signal based on the
Determines whether communication is in progress or not, and
If the request frame signal is received,
When the corresponding response frame signal has not been transmitted
Sends the abnormal response frame signal to the
And a transmission / reception control means for executing processing for returning to the controller.
Network system .