JPH11305810A - Network unit for programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit data from a PC to a general-purpose device without requiring a sequence program in the PC for the data transmission, and to store a sequence program in a PC memory Reduction of area usage, PC
To obtain a network unit for a programmable controller capable of shortening the sequence scan time and reducing the PC load. SOLUTION: In a programmable controller network unit 300 for data communication between a programmable controller 100 and a general-purpose device 200, a registration area in which device information including a device name to be read and a cycle time of data reading are registered. 305
Is provided, and a timer means 306 is provided.
5, the data of the device name to be read is read, and the data is automatically transmitted periodically to the general-purpose device 300 connected to the network.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network unit (communication unit) used for a programmable controller (hereinafter abbreviated as PC) to perform data communication with general-purpose devices.

[0002]

2. Description of the Related Art FIG. 10 shows a general method of performing data communication between a PC and a general-purpose device in a control system using the PC. In FIG. 10, 100 is a PC
And 200 are general-purpose devices such as computers and printers, and 300
Denotes a network unit for transmitting and receiving data between the PC 100 and the general-purpose device 200.

[0003] The network unit 300 is, for example,
The data communication is performed by the start-stop synchronization method.
All communications between the device and the general-purpose device 200 are performed via the network unit 300. The general-purpose device 200 and the network unit 300 are connected by a transmission medium 400. This transmission medium 400 is based on an RS-232C or RS422 / 485 interface if the network unit 300 is a communication unit of the start-stop synchronization system, for example.

In FIG. 10, “Req” indicates the flow of request data from the general-purpose device 200 to the PC 100.
“Ans” indicates the flow of response data from the PC 100 to the general-purpose device 200.

FIG. 11 shows a hardware configuration of the network unit 300. The network unit 300 is a communication window between the MPU 301, the work RAM 302 that is a storage area for transmission / reception data, and the PC 100, and is a 2-port area that can be accessed by both the MPU (not shown) of the PC 100 and the MPU 301 of the network unit 300. It has a RAM 303 and a communication interface unit 304 for connecting a communication interface cable (transmission medium) 400.

There are two methods of notifying the data of the PC 100 to the general-purpose device 200 at regular intervals. The first method is a method in which a user creates a sequence program for creating a message frame on the PC 100 side and transmitting data to the general-purpose device 200 at regular intervals.

FIG. 12 shows an example of a data transmission sequence program for transmitting a transmission request from the PC 100 to the network unit 300 and reading data in the PC. In this sequence program, step S101
, The processing of the timer, steps S102 to S104
, Data transmission processing, step S105, step S1
At step 06, data reception processing is performed.

When the network unit 300 receives a request from the two-port RAM 303, the work unit 302
Transfer the contents of the navel. The MPU 301 analyzes the request, processes the request into transmission data, and processes the transmission data.
4 to the general-purpose device 200. P
When monitoring the value of a device registered in the C100 and transmitting data to the general-purpose device 200 when the device value matches an arbitrary condition specified by the user,
It is necessary to decode the device value at regular intervals by a sequence program, and issue a transmission request from the PC 100 to the network unit 300 if the conditions match.

Further, in these PC data communications, when a plurality of general-purpose devices A, B, and C (100) are connected on one network as shown in FIG. Needs to be configured in consideration of the transmission destination, and it is necessary to set the transmission destination in the two-port RAM 303 of the network unit 300 when transmitting a transmission request.

In another method, a user creates a program for creating a request message frame on the general-purpose device 200 side and transmitting a data read request to the network unit 300 at regular intervals by using a general-purpose language of a computer. Is the way.

FIG. 14 shows an example of a program created by BASIC. This program is created for general equipment 2
00, and is transmitted from the general-purpose device 200 to the network unit 300. In this program, the description in the first to fifth lines is a parameter setting for data transmission, and the description in the sixth to ninth lines is an actual transmission part. In this program, in addition to the above description, a description for setting a timer interval by a property, creating transmission data, and receiving processing is required.

FIG. 15 shows an example of a format of a request message transmitted from the general-purpose device 200. a indicates destination information such as a request address (header), b indicates a request content (command) such as reading or writing, c indicates a device type (device name), and d indicates a head number (address) of a device to be accessed. , E contain the number of devices to be accessed, and f contains information (footer) indicating the end of the message.

When network unit 300 receives a message at communication interface unit 304, MPU 301 stores the message in work RAM 302. When the reception of the message is completed, the MPU 302 converts the data into request data for the PC 100, and transmits the request data to the PC 10 via the two-port RAM 303.
Request to 0. The PC 100 receives the request from the two-port RAM 303 and writes the response data to the two-port RAM 303. After that, the read data from the PC 100 is
When received by the port RAM 303, the contents are stored in the work RAM 302, processed into transmission data by the MPU 301, and transmitted to the general-purpose device 2 by the communication interface unit 304.
Send to 00.

FIG. 16 shows a data flow in the case where a request message frame (request data) is created in the general-purpose device 200 and the request data is transmitted to the network unit 300 at regular intervals. The flow of data is shown when data is transmitted to the general-purpose device 200 at regular intervals by a program. The request data Dr, the response data Da, and the transmission data Ds indicate a message requested from the general-purpose device 200 flowing to the transmission medium 400 to the network unit 300, and A and B represent data exchanged between the PC 100 and the network unit 300. Is shown.

[0015]

[0006] Conventionally, a PC has
When transmitting data from a PC to a general-purpose device, or when monitoring device values at regular intervals, it is necessary for the user to create a sequence program in the PC 100 for performing these processes. For this reason, in the PC 100, a phenomenon of an increase in the size of the sequence program and an increase in the sequence scan occur. In addition, the PC 100 performs all processes such as executing the sequence program, monitoring the status, and managing data transmission to the general-purpose device 200. Originally,
There has been a problem that the ability of the PC 100 is broken for processing other than the sequence processing to be performed by the PC 100.

When data transmission control is performed from the general-purpose device 200, the request data Dr shown in FIG.
It is necessary to transmit the read request data as in
In accordance with the received request message, the network unit 300 must read data from the PC 100 according to the data movement A, and transmit response data from the network unit 300 to the general-purpose device 200 via the transmission medium 400 as response data Da. .

On the other hand, when the transmission is controlled by the sequence program of the PC 100, a transmission request is generated from the PC 100 to the network unit 300 as shown in a data flow B shown in FIG. Only transmission data Ds is transmitted from network unit 300 to general-purpose device 200 like data Ds.

Therefore, when the data transmission control is performed from the general-purpose device 200, compared with the case where the transmission control is performed by the sequence program of the PC 100, the reception on the network unit 300 side corresponds to the required request message. This requires processing, which increases the load on the system and slows down the response transmission.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. A data transmission from a PC to a general-purpose device includes a sequence program on the PC for the data transmission, and a program on the general-purpose device side. It can also be performed without the need to repeatedly receive a request message from a general-purpose device, reducing the use of the PC memory area for storing sequence programs, reducing the PC sequence scan time, and reducing the PC load. Network for programmable controllers that can reduce the number of general-purpose devices at the transmission destination due to system changes, etc. without having to rewrite programs. The aim is to get a unit.

[0020]

To achieve the above object, a network unit for a programmable controller according to the present invention is provided in a network unit for a programmable controller for data communication between the programmable controller and general-purpose equipment. Storage means including a registration area in which device information including a device name to be read and a cycle time of data reading are registered, and a timer means, and the registration area is stored in the registration area for each cycle time registered in the registration area. It reads the data of the registered device name to be read, and automatically transmits the data periodically to general-purpose devices connected to the network.

A network unit for a programmable controller according to the next invention is a network unit for a programmable controller for data communication between a programmable controller and a general-purpose device, wherein device information including a device name to be read and data read conditions are included. A storage unit including a registration area for registering a value and a cycle time for reading data; and a timer unit, and a device name of a device to be read registered in the registration area for each cycle time registered in the registration area. The data is read out, and if it matches the data reading condition value registered in the registration area, the data is automatically transmitted to a general-purpose device connected to the network.

In the network unit for a programmable controller according to the next invention, the registration area includes a registration area of transmission destination information, and if a data read condition value registered in the registration area matches, a plurality of network-connected devices are connected. Data is automatically transmitted to general-purpose devices designated by destination information registered in the registration area among the general-purpose devices.

In the network unit for a programmable controller according to the next invention, information registration in the registration area is performed by receiving a registration message from a general-purpose device connected to the network.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a network unit for a programmable controller according to the present invention will be described below in detail with reference to the accompanying drawings. In the embodiments of the present invention described below, the same components as those of the above-described conventional example are denoted by the same reference numerals as those of the above-described conventional example, and description thereof will be omitted.

Embodiment 1 1 to 4 show a first embodiment of a network unit for a programmable controller according to the present invention. As shown in FIG. 1, the network unit 300
01, a work RAM 302, a two-port RAM 303, a communication interface unit 304, and a registration area 30 of a RAM (storage means) for registering a condition of a fixed period transmission.
5 and a timer 306 that counts a fixed period for cyclic transmission. Network unit 3
00 receives the registration message created by the general-purpose device 200,
According to the contents of the registration message, a condition for transmission at regular intervals is registered in the registration area 305.

FIG. 2 shows an example of the format of a registration message for transmission at a fixed period. The registration message includes a header g, a command h indicating registration for transmission at a fixed period, and the PC 100.
From the network unit 300 to read data from the PC 100, a device name (read target device name) j to be read from the PC 100, a head number (address) k of the device, a point 1 of the device to be read, and a footer m. H to l are registered areas 30
5, and j to l are read device information. Note that the command h is a number indicating a fixed-cycle transmission, and is a newly created number based on the registration means for the fixed-cycle transmission.

The registration area 305 includes a registration area 305a for a command h indicating a fixed period transmission registration and a registration area 30 for a cycle time i (set time of the timer 306) for the network unit 300 to read data from the PC 100.
5b, a registration area 305c of a device name j read from the PC 100, and a head number (address) of the device
k registration area 305d and the number l of devices to be read
And a registration area 305e. Note that the set time of the timer 306 can be registered in the timer 306 itself.

As described above, the data of the fixed-cycle transmission is registered and held in the registration area 305 of the network unit 300 that controls the fixed-cycle transmission.
The transmission of the registration data of the fixed period transmission to the network unit 300 only needs to be performed once at the start of the fixed period transmission, and the registration data of the fixed period transmission is transmitted to the network unit 300 unless the contents of the fixed period transmission are changed. No need. This is one characteristic of the network unit according to the present invention.

FIG. 3 is a flowchart showing the procedure of the transmission processing of the network unit 300 at a fixed period. When the network unit 300 receives a registration message in a format as shown in FIG. 2 from the general-purpose device 200 at the communication interface unit 304, the data is analyzed by the MPU 301, and the cycle time and the read device information are registered in the registration area 305. (Steps S10 and S10)
11). The timer 306 checks the time, and when the registered cycle time (specified time) has elapsed (Yes at Step S12), the timer 306 issues an operation request to the MPU 301.

If the device name j registered in the registration area 305 is data in the PC 100 (Yes at step S13), the MPU 301
The data in C100 is read (step S1).
4) The read data is processed by the MPU 301 into a message frame format, and transmitted from the communication interface unit 304 to the general-purpose device 200 (step S15). When the transmission is completed, the process returns to step S12 to check the time by the timer 306.
The transmission is repeated for a fixed period with reference to the registered contents of.

The device name j registered in the registration area 305 is the two-port RA of the network unit 300.
If the data is M303 data (No at step S13), the two-port RAM 303 is similarly processed by the message creation process.
(Step S16), the read data is processed into a message frame format by the MPU 301, and the general-purpose device 20 is transmitted from the communication interface unit 304.
0 (step S15).

In this case as well, when the transmission is completed, the process returns to step S12, where the time is checked by the timer 306, and thereafter, the transmission is repeated for a fixed period with reference to the registration contents of the registration area 305.

FIG. 4 shows the network unit 30 described above.
9 shows a data flow when transmission is performed at a fixed period using 0. FIG. 4 shows the network unit 3 between the PC 100 and the network unit 300 as in FIG.
FIG. 5 is a diagram showing a flow of data between the general-purpose device 200 and the general-purpose device 200, where Dsr is registration data (registration message) transmitted at a fixed period transmitted from the general-purpose device 200 to the network unit 300; Registration data Dsr
Area 3 in network unit 300 based on
Registration of fixed period transmission information with respect to PC05, PC 100
And Ds indicates data transmitted from the network unit 300 to the general-purpose device 200.

As described above, the data of the fixed-cycle transmission is registered and held in the registration area 305 of the network unit 300 that controls the fixed-cycle transmission.
The transmission of the registration data of the fixed period transmission to the network unit 300 only needs to be performed once at the start of the fixed period transmission, and the registration data of the fixed period transmission is transmitted to the network unit 300 unless the contents of the fixed period transmission are changed. No need. This is one characteristic of the network unit according to the present invention.

Embodiment 2 5 to 9 show a second embodiment of a network unit for a programmable controller according to the present invention. In FIGS. 5 to 9, parts corresponding to FIGS. 1 to 4 are denoted by the same reference numerals as those in FIG. 1, and the description thereof may be omitted.

Also in this embodiment, as shown in FIG. 5, the network unit 300
301, a work RAM 302, a two-port RAM 303,
In addition to the communication interface unit 304, a registration area 307 by a RAM for registering conditions for device monitoring automatic transmission.
And a timer 30 for counting the transmission period (constant period transmission)
6. The network unit 300 receives the registration message created by the general-purpose device 200, and registers conditions for automatic device monitoring transmission in the registration area 307 according to the content of the registration message.

FIG. 6 shows an example of the format of a registration message for automatic device monitoring transmission. The registration message includes a header n, a command o indicating device monitoring automatic transmission registration, a data read cycle time p, a device name q read from the PC 100, a head number (address) r of the device, and a data transmission trigger. It is composed of a device value (data read condition value) s, destination information t specifying a destination, and a footer u.
t is registration information for the registration area 306, and j to l
Is read device information. The command o is a number indicating the device monitoring automatic transmission, and is a newly created number based on the device monitoring automatic transmission registration unit. As shown in FIG. 13, when there are a plurality of general-purpose devices in one system, the transmission destination information t specifies the general-purpose device of the transmission destination.

The registration area 307 includes a registration area 307a for a command o indicating device monitoring automatic transmission, a registration area 307b for a data read cycle time (set time of the timer 306) p, and a registration area 307c for a device name q.
A registration area 307d for the head number (address) r of the device, a registration area 307e for the condition value s for data reading, and a registration area 307f for the destination information t are defined.

FIG. 7 is a flowchart showing a procedure of processing for automatic transmission of device monitoring by the network unit 300. A registration message in a format as shown in FIG.
When 00 is received by the communication interface unit 304, the data is analyzed by the MPU 301, and read device information including a period time and a read condition value is registered in the registration area 307.
(Steps S20 and S21).

The timer 306 checks the time, and when the registered cycle time (specified time) has elapsed (Yes at step S22), the timer 306 issues an operation request to the MPU 301.
The MPU 301 determines that the device name q registered in the registration area 307 is data in the PC 100 (step S23).
(Affirmative) Data is read from the PC 100 through the two-port RAM 303 (step S24).

Next, the device value of the data is compared with the condition value s registered in the condition value registration area 307e of the registration area 307 (step S25). If the condition matches (Yes at step S25b), the read data is stored in M
The message is processed into a message frame format by the PU 301 and is transmitted from the communication interface unit 304 to the general-purpose device 200 (step S26). When the transmission is completed, the process returns to step S22, and the time is checked by the timer 306.
Similarly, the device monitoring automatic transmission is repeated with reference to the registration contents of the registration area 307.

The device name q registered in the registration area 307 is the two-port RA of the network unit 300.
If the data is M303 data (No at step S23), the two-port RAM 303 is similarly processed by the message creation process.
Is read (step S27), the device value of the data is compared with the condition value s registered in the condition value registration area 307e of the registration area 307 (step S25), and if the conditions match (step S25b) (Affirmative), the read data is processed by the MPU 301 into a message frame format, and transmitted from the communication interface unit 304 to the general-purpose device 200 (step S26). Also in this case, when the transmission is completed, the process returns to step S22 to check the time by the timer 306, and thereafter, the device monitoring automatic transmission is repeated with reference to the registered contents of the registration area 307.

As an example of use of this embodiment, if a device for storing an error is specified in the device name q and the address r, data is sent to the general-purpose device 200 when an error occurs in a unit that sets an error code in a corresponding area. If the device that stores the current time is specified in the device name q and the address r, the data can be transmitted to the general-purpose device 200 at the scheduled time.

FIG. 8 shows the network unit 30 described above.
0 shows the flow of data when device monitoring automatic transmission is performed using 0. FIG. 8 shows the PC 100 as in FIG.
FIG. 3 is a diagram showing a data flow between the network unit 300 and the network unit 300, and between the network unit 300 and the general-purpose device 200, where Dsr is registration data (for device monitoring automatic transmission) transmitted from the general-purpose device 200 to the network unit 300; Registration message), C is a network unit 300 based on registration data Dsr from the general-purpose device 200.
Registration of device monitoring automatic transmission to the registration area 307 in the PC, D is the PC 100 and the network unit 300
Ds indicates data transmitted from the network unit 300 to the general-purpose device 200.

As described above, the data for the device monitoring automatic transmission is registered and held in the registration area 307 of the network unit 300 that controls the device monitoring automatic transmission.
The transmission of registration data for device monitoring automatic transmission to
It only needs to be performed once at the start of device monitoring automatic transmission, and unless the content of device monitoring automatic transmission is changed,
It is not necessary to transmit registration data for device monitoring automatic transmission to the network unit 300. This is one characteristic of the network unit according to the present invention.

Further, by setting the destination information t in the device monitoring automatic transmission registration, the destination of data transmission can be arbitrarily specified. In this case, the data transmission process in step S26 in FIG. 7 is performed according to the transmission destination device designation process shown in FIG. In this transmission destination device designation process, it is determined which condition is matched (step S30). Accordingly, the network unit 300 determines the transmission destination device based on the matched condition, and attaches the transmission destination device information to the header in the message frame created by the MPU 301 and transmits the message (steps S31 to S33).

In the example as shown in FIG. 13, if the condition 2 is satisfied, for example, if an error occurs in the network unit 300, the fact is notified to the general-purpose device B, and if the condition 3 is satisfied, For example, at 8:00 every day, data is transmitted to the general-purpose device C.

As described above, if data is transmitted to the device according to the condition, only the necessary general-purpose device can be notified, and the efficiency of the entire system increases.

[0049]

As can be understood from the above description, according to the network unit for a programmable controller according to the present invention, the device information including the device name to be read and the data read cycle time are built in the network unit. Registered in the registration area of the storage means, based on the registered content of the registration area data transmission control, that is, for each periodic time registered in the registration area,
Since the data of the device name to be read registered in the registration area is read and the data is automatically transmitted periodically to the general-purpose device, it is possible to perform the transmission at regular intervals without creating a sequence program and store the sequence program. This reduces the amount of PC memory area used and reduces the sequence scan time.
Since data transmission is controlled by the network unit, P
The load on C is reduced, and the ability of the PC that should be used to execute the sequence program can be fully utilized. In addition, since there is no need for the program on the general-purpose device or the repetitive reception processing of the request message from the general-purpose device,
The load on the system is reduced, and the response can be transmitted quickly.

According to the network unit for the programmable controller according to the next invention, the device information including the device name to be read and the cycle time for reading the data read condition value data are stored in the registration area of the storage means built in the network unit. Data transmission control based on the registered contents of the registration area, that is, for each cycle time registered in the registration area, reads out the data of the device name to be read registered in the registration area, and registers in the registration area If the data read condition value matches the data, the data is automatically transmitted periodically to the general-purpose device. Therefore, it is possible to perform the device monitor automatic transmission without creating a sequence program, and the PC memory area for storing the sequence program is stored. Usage is reduced,
The effect of shortening the sequence scan time is obtained. Since the data transmission is controlled by the network unit, the load on the PC is reduced, and the ability of the PC that should be used for executing the sequence program can be fully utilized. Further, since there is no need for a program on the general-purpose device or a process of repeatedly receiving a request message from the general-purpose device, the load on the system is reduced, and the response can be transmitted quickly.

According to the network unit for the programmable controller according to the next invention, the destination information is also registered in the registration area of the storage means built in the network unit, and coincides with the data read condition value registered in the registration area. For example, data is automatically transmitted to the general-purpose device specified by the destination information registered in the registration area, so if the destination device changes due to a system change, etc., there is no need to modify the sequence program, and Only the registered contents of the destination information need be changed.

According to the network unit for a programmable controller according to the next invention, information registration in the registration area is performed by receiving a registration message from a general-purpose device connected to the network. The information registration in the registration area can be changed without making the network unit complicated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a hardware configuration of a network unit for a programmable controller according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram showing a format of a registration message from a general-purpose device when a fixed period transmission is performed.

FIG. 3 is a flowchart showing a procedure of a fixed-cycle transmission process performed by the network unit according to the present invention.

FIG. 4 is a time chart of a data flow when data is transmitted from a PC to a general-purpose device at a constant period by a network unit according to the present invention.

FIG. 5 is a block diagram showing a hardware configuration of a network unit for a programmable controller according to a second embodiment of the present invention;

FIG. 6 is an explanatory diagram showing a format of a registration message from a general-purpose device when performing device monitoring automatic transmission.

FIG. 7 is a flowchart showing a procedure of a device monitoring automatic transmission process performed by the network unit according to the present invention.

FIG. 8 is a time chart of a data flow when data is transmitted from the PC to the general-purpose device in the device monitoring state by the network unit according to the present invention.

FIG. 9 is a flowchart illustrating a procedure of a data transmission destination specification process performed by the network unit according to the present invention.

FIG. 10 is a diagram illustrating a general system configuration when performing data communication between a PC and a general-purpose device via a network unit.

FIG. 11 is a block diagram showing a hardware configuration of a conventional network unit.

FIG. 12 is a ladder diagram illustrating an example of a sequence program for transmitting data from a PC to a general-purpose device at a constant cycle.

FIG. 13 is a diagram showing a general system configuration when data communication is performed between a PC and a plurality of general-purpose devices via a network unit.

FIG. 14 is a program list diagram showing a program example of a general-purpose device for reading data of a PC from a general-purpose device at a constant cycle.

FIG. 15 is an explanatory diagram showing an example of a message format when performing data communication from a general-purpose device to a PC via a conventional network unit.

FIG. 16 is a time chart of a data flow when data of a PC is read from the general-purpose device at a constant cycle.

FIG. 17 is a time chart of a data flow when data is transmitted from a PC to a general-purpose device at a constant cycle. FIG. 6 is a diagram of data flowing on a line.

[Explanation of symbols]

100 PC, 200 general equipment, 300 network unit, 301 MPU, 302 work, 303
2 port RAM, 304 communication interface unit, 30
5 registration area, 306 timer, 307 registration area, 400 transmission medium.

Claims (4)

[Claims] 1. A network unit for a programmable controller for data communication between a programmable controller and a general-purpose device, comprising a registration area for registering device information including a device name to be read and a cycle time of data reading. A storage unit, and a timer unit, which reads data of a device name to be read registered in the registration area for each cycle time registered in the registration area, and periodically transmits the data to a general-purpose device connected to a network. A network unit for a programmable controller characterized by automatic transmission. 2. A network unit for a programmable controller for data communication between the programmable controller and a general-purpose device, wherein device information including a device name to be read, a data read condition value, and a data read cycle time are registered. Storage means including a registration area, and timer means,
The data of the device name to be read registered in the registration area is read out at each cycle time registered in the registration area. If the data matches the data reading condition value registered in the registration area, the general-purpose network-connected A network unit for a programmable controller, which automatically transmits data to a device. 3. The registration area includes a registration area of transmission destination information, and, if a data reading condition value registered in the registration area matches, the registration area of a plurality of general-purpose devices connected to a network. The network unit for a programmable controller according to claim 2, wherein data is automatically transmitted to a general-purpose device specified by registered destination information. 4. The information registration in the registration area is performed by receiving a registration message from a general-purpose device connected to a network.
A network unit for a programmable controller according to any one of the above.