JP2002063046A - Control device and recording medium with its program recorded thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device, capable of safely and surely holding a user program, in spite of its being editable on-line. SOLUTION: A control/display device 3 normally alternately executes control processing, based on an instruction list formed by developing the user program and image screen renewing processing according to a state of a device 2a, and when indicating on-line editing, the control/display device 3 changes the instruction list instead of the image screen renewing processing. After finishing editing, the control/display device 3 displays, so as to store the user program in a first user program storage part 31 of a Static RAM and to store the user program, in a second user program storage part 33 of a flash ROM. The control/display device 3 reads out the user program from the second user program storage part 33, when the user program of the first user program storage part 31 is lost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a device based on a user program stored in advance, such as a ladder program, and more particularly to a control device for safely holding a user program and changing a program during control. The present invention relates to a control device capable of satisfying both.

[0002]

2. Description of the Related Art Conventionally, in a control system, a programmed control device has been widely used to control a device of a target system. In these control devices, for example, a computer connected to a maintenance port or the like of the control device while the control device stops controlling the device, such as when the control device is installed or the operation of the target system is suspended. Then, a ladder program indicating the control contents of the device is downloaded. further,
The control device controls each device during normal operation by repeatedly executing a ladder program stored in the own device.

Further, when it is necessary to significantly change the ladder program, for example, when changing the device connected to the control device, the control device interrupts normal operation and is reconnected to the maintenance port. Download a new ladder program from your computer.

Here, in a control system, since operation stoppage is directly linked to an accident or deterioration of business performance, it is strongly required that the operation always be performed as compared with OA equipment or the like. Therefore, in recent years, a control device having an online edit function and capable of changing a part of the ladder program between repeated executions of the ladder program for small changes is being used.

[0005]

However, in the control device having the above-described online editing function, the ladder program is rewritten at a high speed during the online editing by using an SRAM (Static RA).
M). Therefore, even if the SRAM is backed up by a battery, if the battery runs out due to an accident such as a long-term power outage, it is necessary to download the ladder program again, and it takes time and effort to recover from the accident. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to control a user program such as a ladder program, which can be edited online, while maintaining the user program safely and securely. It is to implement the device.

[0007]

According to a first aspect of the present invention, there is provided a control device for controlling a device by repeatedly executing a user program stored in a storage unit to control a device. In a control device having online editing means for changing the user program in response to an instruction from an external device between executions of the user program repeatedly, the following means are provided.

That is, the storage means includes a rewritable nonvolatile memory and a volatile memory having a higher writing speed than the nonvolatile memory. Further, the online editing means changes a user program stored in the volatile memory. The control device further includes a writing unit that stores the user program stored in the volatile memory in the nonvolatile memory; and a nonvolatile memory that stores the user program in a case where the volatile memory cannot normally hold the user program. And a reading control means for reading a user program from the CPU.

[0009] In the above configuration, the online editing means changes the user program stored in the volatile memory, which is faster in writing speed than the nonvolatile memory, in the storage means. Thus, even when the user program is frequently changed, such as during online editing, the control device terminates the execution of the user program and then starts the execution of the user program without any problem. In between, the user program can be changed.

Further, when the online editing is completed, the writing means stores the user program stored in the volatile memory also in the non-volatile memory in accordance with, for example, a user's instruction. On the other hand, when the volatile memory cannot hold the user program, for example, when a power failure occurs, or when the battery runs out even if the volatile memory is backed up by a battery, the read control unit reads the user program from the nonvolatile memory. Load the program. Thus, even when the volatile memory cannot hold the user program, the control device can start device control without any trouble based on the user program in the nonvolatile memory without communicating with an external device. .

As a result, despite the fact that the user program can be edited online, even if an accident such as a power failure or running out of battery occurs, the user program can be securely and securely retained, and the external Compared with the prior art in which a user program is downloaded from a device, the time and labor required to recover from an accident can be reduced.

Further, the control device according to the invention of claim 2 is:
2. The configuration according to claim 1, wherein at least a part of said volatile memory is backed up by a battery, and said device control means stores an instruction list in which a user program is expanded in said volatile memory. While executing the list, the online editing means changes the instruction list during online editing, and after the online editing is completed, receives a user program before developing the instruction list from the external device, and stores the volatile memory in the volatile memory. Among them, it is characterized in that it is stored in a battery-backed up area.

In the above configuration, during online editing,
Since the online edit means changes the instruction list, the amount of calculation at the time of the change can be reduced as compared with the case where the user program before the development is updated and then the instruction list is developed again. Also, when the online editing is completed, the user program before expansion is received from the external device and stored in the volatile memory, so that the user program can be surely executed with a smaller amount of computation than restoring the user program before expansion from the instruction list. Programs can be stored in volatile memory. As a result, online editing can be performed without placing a burden on the control device.

Further, since the area for storing the user program before expansion in the volatile memory is backed up by a battery, even if the power is interrupted while the writing means is writing the user program to the non-volatile memory, the user is not affected. Can hold programs. As a result,
The user program can be stored in the non-volatile memory, and the user program can be held more safely.

The control device according to the invention of claim 3 is
3. The configuration according to claim 1, further comprising: a notifying unit that notifies a user to update the user program in the nonvolatile memory when the online editing unit changes the user program in the volatile memory. The writing means, in response to an instruction from a user,
It is characterized in that a user program is written in the nonvolatile memory.

If the online editing means changes the user program in the volatile memory and the user program in the non-volatile memory does not match the user program in the volatile memory, the notification means may display, for example, on a screen. The user is notified to update the user program in the non-volatile memory by, for example, notifying by voice. On the other hand, when the user instructs writing when the control and display of the device are not hindered, the writing unit writes the user program in the volatile memory to the nonvolatile memory to update the content of the nonvolatile memory. As a result, although the contents of the non-volatile memory can be updated at the time desired by the user of the control device, forgetting to update can be prevented.

When the control device has a function of displaying a device state and a function of receiving a control instruction from a user, and is also used as an HMI (Huma-Machine Interface) device, the user gives an instruction. If the contents of the non-volatile memory are automatically updated during the operation, the response time to the user's instruction will be delayed due to the contents update processing,
There is a possibility that the user cannot respond. Therefore, in particular, HM
When used as an I device, it is preferable that the writing means update the contents of the nonvolatile memory in accordance with an instruction from the user.

The control device according to a fourth aspect of the present invention is the control device according to the first, second, or third aspect of the present invention.
While the device control means repeatedly executes the user program, a display means for updating a display screen in accordance with the state of the device, and in the case of online editing, the display update processing is given priority over the display update processing by the display means. It is characterized in that the editing means is provided with an execution control means for changing the user program.

In the above configuration, since the control device includes the display means, a period for the display means to update the screen is provided between the device control means repeatedly executing the user program. Here, at the time of online editing, the execution control unit changes the user program with higher priority than the display update process, for example, by stopping a part or all of the display update process. Therefore, it has no display means and normally executes the next cycle of the user program at the same time as the execution of the user program ends. During online editing, the execution of the user program and the change of the user program are alternately executed. Configuration, or after the display means has performed all the display update processing, compared to a configuration in which the user program is changed, without significantly changing the execution cycle of the user program,
You can edit online.

On the other hand, a recording medium according to a fifth aspect of the present invention
A recording medium that has a rewritable nonvolatile memory and a volatile memory whose writing speed is faster than the nonvolatile memory, and stores a program for operating a computer capable of communicating with an external device as a control device. hand,
In order to solve the above-mentioned problem, a user of the volatile memory is controlled in accordance with an instruction from the external device while the user program stored in the volatile memory is repeatedly executed to control a device to be controlled. Online editing means for changing a program, writing means for storing a user program stored in the volatile memory in the non-volatile memory, and non-volatile memory if the volatile memory cannot normally hold the user program. As a reading control unit for reading a user program from a memory, a program for operating the computer is recorded.

When the program having the above configuration is read from the recording medium and executed by the computer, the computer operates as the control device according to claim 1. Therefore, although the user program can be edited online, the time and labor required to recover from an accident such as a power failure or running out of battery can be reduced.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention.
This will be described below with reference to FIG.
That is, as shown in FIG. 1, a control system 1 according to the present embodiment is a system that controls the state of a target system 2 including devices 2a, such as motors, valves, and sensors. A control / display device (control device) 3 for controlling the target system 2 in accordance with the status of the target system 2 to the operator and a ladder to which the control / display device 3 refers when controlling the input / output devices 2a. Computer (external device) that creates user programs such as programs
4 are provided.

The control / display device 3 according to the present embodiment is realized, for example, as a programmable display device having a programmable logic controller (PLC) function capable of directly controlling the input / output device 2a. 2 is provided.
That is, the control / display device 3 is connected to a memory unit (storage means) 11 for storing programs, data, and the like, the computer 4, the liquid crystal display device 13a as a display device, and the touch panel 14a as an input device. Circuit 12 for display, display controller 1
3 and a touch panel controller 14, an I / O unit 15 for directly controlling the device 2a shown in FIG.
A CPU (Central Processing Unit) 16 for controlling the circuits 12 to 15 with reference to the memory unit 11 is provided.

The communication circuit 12 is, for example, an Ethernet (registered trademark) interface circuit or a serial interface, and communicates with the computer 4 which is connected at least during maintenance such as online editing or initial setting, which will be described later. Thus, the user program and other data created by the ladder editor of the computer 4 can be downloaded. Note that the communication circuit 12 and the computer 4 or another control / display device 3 may be constantly connected to control the target system 2 while cooperating with each other.

The I / O unit 15 includes a number of input / output terminals and input / output circuits connected to each device 2a, an input / output memory, a D / A converter, an A / D converter, and the like. Thus, digital or analog signals input / output via input / output terminals can be exchanged with the CPU 16.

On the other hand, the memory unit 11 has a ROM (Read Onl
y Memory) 11a and FEPROM (Flash Erasable and Programmable) as a rewritable nonvolatile memory
eROM) 11b, an SRAM (Static RAM) 11c as a volatile memory backed up by a battery, and a main memory 11d as a volatile memory such as a DRAM (Dynamic RAM).

The ROM 11a stores, for example, an initialization program executed when the power is turned on, font data, and the like. The FEPROM 11b performs display / control based on user screen data described later and the user screen data. And a display control system program. The SRAM 11c stores a user program created by a ladder editor described later.
Used as a user program storage unit 31 (see FIG. 1). Further, the main memory 11d includes an instruction list storage unit 32 (see FIG. 1) in which an instruction list in which the user program is developed is stored.
Alternatively, it is used as an area or a work area to be developed when executing another program stored in each of the memories 11a to 11c. Since these memory units 11 are all semiconductor memories, they have no movable parts and are resistant to impact. Therefore, stable operation can be continued even in a poor surrounding environment such as the vicinity of the target system 2.

Further, in the present embodiment, the FEPROM 11 is provided separately from the first user program storage section 31 in which the user program is written at the time of online editing.
A second user program storage unit 33 (see FIG. 1) for storing a user program is also provided in b. SRAM 11c serving as the first user program storage unit 31
Can write faster than the FEPROM 11b, for example, writing one word in several tens of ns. On the other hand, the writing speed of the FEPROM 11b is slower than that of the SRAM 11c, but the capacity is relatively large, and the contents can be held even when power is not supplied. Therefore, the user program can be retained even when the battery for backing up the SRAM 11c runs out, such as when power supply to the control / display device 3 is stopped for a long time.

Control / display device 3 of the above hardware configuration
When the power is turned on, the CPU 16 executes the program of the memory unit 11 to control the peripheral circuits 12 to 15, and the functional blocks 31 to 38 shown in FIG. 1 are formed. That is, the state memory 34 is realized as an area of the main memory 11d or the like, and stores the state of each device 2a. Also, the I / O processing unit 35
It communicates with each of the devices 2a through the unit 15,
The state of the device 2a is made to match the contents of the state memory 34. More specifically, when the device 2a is an input device, the status of the device 2a is written to an address corresponding to each device 2a in the storage area of the status memory 34 based on an input signal from the device 2a. On the other hand, when the device 2a is an output device, the state memory 3
And outputs a control instruction corresponding to the contents of the device 4 to the device 2a.

Further, the device control section (device control means) 36 stores the instruction list storage section 32
By writing to the state memory 34 with reference to the state memory 34, the devices 2a can be controlled according to a user program. Further, the display / operation processing unit (display means) 37 refers to the state memory 34 and updates the display screen of the liquid crystal display device 13a according to the state of each device 2a. In addition, the display / operation processing unit 37 can rewrite the contents of the state memory 34 according to a user's instruction input to the touch panel 14a. Further, the execution control unit 38 (execution control means) includes an I / O processing unit 35, a device control unit 36, a display / operation processing unit 37, or a communication processing unit 41 and a program editing unit 4 described later.
2 and the like.

The functional block includes a communication circuit 1
Communication processing unit 4 that communicates with computer 4 connected to
1, a program editing unit (online editing means) 42 for rewriting the contents of the instruction list storage unit 32 and the first user program storage unit 31 in accordance with the communication result when performing online editing, and a first user program storage unit 31 ( When the user program in the SRAM 11c) is changed, for example, "
Display a predetermined character string such as "No backup available" to match the user program.
A backup processing unit (writing means; writing means; which prompts the user to update the user program in the user program storage unit 33 (FEPROM 11b) and updates the user program in the second user program storage unit 33 in response to an instruction from the user. (Notifying means) 43.

Further, the functional block also includes an activation control unit (reading control means) 44 formed when the control / display device 3 is activated, and the two user programs are activated when the control / display device 3 is activated. By expanding the user program read from one of the storage units 31 and 33, an instruction list can be generated and stored in the instruction list storage unit 32.

In the above configuration, during the normal operation, the control / display device 3 performs the steps 1 to 6 shown in FIG. 3 every predetermined period (scan time), for example, about every 50 ms.
(Hereinafter, the processing is abbreviated as S1 to S6) is sequentially repeated.

More specifically, the I / O processing unit 35
In, the state of each device 2a is read and written to an address corresponding to each device 2a in the storage area of the state memory. In S2, the device control unit 36 sequentially executes each instruction in the instruction list stored in the instruction list storage unit 32 while referring to the contents of the state memory 34. The contents of the state memory 34 are changed according to each instruction. Further, when the end instruction is executed and the execution of the instruction list ends, in S3, the I / O processing unit 35
Writes the contents of the state memory 34 to the device 2a.
Accordingly, the device control unit 36, like the PLC,
Each device 2a can be controlled according to the state of the device 2a according to a user program. In the case of the present embodiment, the period required for the processing of S1 to S3 is, for example, about 20 ms.

The control / display device 3 according to the present embodiment
Is a program display device having a PLC function and a display / operation function, and a period for updating the display screen (for example, about 30 ms) is provided between the controls of the device 2a. During this period, if the computer 4 has not instructed the online editing (in the case of no instruction in S4), the display / operation processing unit 37 outputs the FEPROM 11b.
The display screen is updated based on the user screen data stored in (5) (S5).

More specifically, the user screen data includes a base screen to be displayed on the liquid crystal display device 13a, mark data as an image block, and a processing instruction word (tag) assigned to each mark. And constitutes a display content program. The above-mentioned marks are prepared in advance as imaged basic parts such as touch switches, lamps, various displays, and the like. In addition, as a mark, a moving image function unit in which a desired moving image function is set in a rectangular area set at a desired position in order to express a dynamic change of a switch, a numerical display, or the like at an arbitrary position on a screen. Is also included.

The tag is created for each event to be executed on the base screen. Basically, the file number of the base screen on which the display control operation is to be executed and the tag to be executed on the base screen are performed. Event name that specifies the action to be performed,
Reference information including one or a plurality of data referred to for each execution event is provided as a set. For example, in the case of a display tag that displays a component graphic corresponding to the content of a predetermined device address in a predetermined screen area (display coordinate range), the reference information includes the display coordinate range (X · Y), the device address, and the like. For example, when the component graphic is a switch, the file includes a file number to be referred to at the time of display, such as a graphic file indicating ON and a graphic file indicating OFF. When the tag is an input tag, the reference information includes a valid input coordinate range (XY) and a device address to which an input result is written.

In step S5, the display / operation processing unit 37 extracts a display tag whose file number of the base screen is the currently displayed base screen from the user screen data stored in the FEPROM 11b, With respect to (3), the contents of the device address associated with the display tag are read from the state memory 34, and the component graphic corresponding to the read value is displayed in the display coordinate range of the screen. Here, if the above S5 is not during online editing,
It is executed every scan time. Therefore, the current state of the device 2a is reflected on the screen of the liquid crystal display device 13a. Further, when receiving an input operation of the operator such as a pressing operation on the touch panel 14a, the display / operation processing unit 37, based on the user screen data, corresponds to the base screen currently displayed and matches the input tag matching the input operation. And changes the content of the device address indicated by the input tag in the state memory 34 according to the input result. Here, since the change in the contents of the state memory 34 is reflected on the device 2a for each scan time, each device 2a can be controlled according to the operation of the operator.

On the other hand, when online editing is instructed from the computer 4 (if there is an instruction in S4), the execution control unit 38 sends the program to the program editing unit 42 instead of the display / operation processing unit 37 in S6. The user program is edited online, and if there is room, the display screen is updated in S5. If the display scan time becomes longer if both the online editing process and the display screen updating process are performed, the online editing process is prioritized, and part or all of the display screen updating process is omitted. In this case, for example, there is a possibility that dropped frames may be visually recognized when the movement is fast. However, when the online editing period ends, the display screen is updated, so that the operator can control / display without any trouble. The status of the device can be grasped and controlled by displaying and operating the device 3.

Here, the commands that can be operated by the user of the computer 4 during online editing are limited to some commands that can be processed in a short time, as described later. The instruction list is sequentially changed according to the instruction from. Further, while sequentially changing the instruction list, the control / display device 3 gives priority to display processing,
The instruction list has been changed, and at least a part of the display processing can be stopped. Thus, even during online editing, the length of the scan time is maintained at substantially the same length as in the case where control processing of each device 2a according to the user program and display processing of the state of the device 2a are performed. . Therefore, regardless of whether or not online editing is being performed, the control / display device 3 can repeatedly execute the user program at a substantially constant cycle (for example, about 50 ms).

When a user program is transmitted from the computer 4 upon completion of online editing, the program editing unit 42 stores the user program in the first user program storage unit 31. Thereby, the contents of the first user program storage unit 31 are updated based on the edited instruction list,
The user program can be updated more accurately and faster than when the second user program storage unit 33 that is a part of the EPROM 11b is rewritten. The program editing unit 4
Reference numeral 2 also stores the checksum of the user program when the user program is written in the first user program storage unit 31.

Here, the online editing is completed,
At the stage of shifting to the offline mode, the user program has been written in the first user program storage section 31 but not in the second user program storage section 33. In this state, for example, the touch panel 14a
When a predetermined specific operation, such as three of the four corners of the four display screens, is performed, the display / operation processing unit 37 displays a maintenance menu screen, for example, as shown in FIG. Further, when the controller backup item is selected from the menu selection items, the backup processing unit 43 displays a user program (ladder program) storage item as shown in FIG. 5, and the item is selected. Then, the user program stored in the first user program storage unit 31 is written to the second user program storage unit 33. The second user program storage unit 33 is realized as an area of the FEPROM 11b, and can hold the user program even when the power supply is stopped for a long time, but has a lower writing speed than the SRAM 11c. Therefore, the backup processing unit 4
3, while writing the user program (ladder program), as shown in FIG. 6, displays on the display screen of the liquid crystal display device 13a that the writing is being performed, and informs the operator not to turn off the power. .

When the power of the control / display device 3 is turned on, for example, when the operation of the target system 2 is stopped and the operation is restarted, the C / C of the control / display device 3 is turned off.
The PU 16 executes a boot program stored in the ROM 11a or the FEPROM 11b in advance, and the boot control unit 44 shown in FIG. 1 is formed as a functional block. In S11 shown in FIG. 7, the activation control unit 44
A string (signature) stored in a specific area of 1c is collated. The string is an SRAM 11
This is a fixed text stored to confirm whether or not the content of c is normal, and the value is held while the SRAM 11c is backed up by a battery. However, if the battery runs out due to, for example, a long-time power supply stop, the SRAM 11c cannot hold the string. Therefore, whether or not the battery has run out can be identified by collating the strings.

If the verification is successful, the activation control unit 44
In S12, for example, the SRAM 11c or FEPRO
A predetermined area of M11b or a dip switch,
With reference to the ladder flag stored in the non-volatile storage means, of the SRAM 11c and the FEPROM 11b,
User program storage units 31 and 33 provided in either
, It is determined whether to read the user program.

Here, usually, the ladder flag is set in the SRAM
The user program is set to be read from the first user program storage section 11c (first user program storage section 31) (in the case of SRAM in S12). Therefore, the activation control unit 44
In S13, the first user program storage unit 31
, The checksum stored in the first user program storage unit 31 is compared with the checksum calculated from the read user program, and the user program in the first user program storage unit 31 is correctly stored. Check if you have been. If the checksum verification fails, the activation control unit 44
In S31, for example, a "major abnormality" is displayed on the liquid crystal display device 13a to notify the operator of the control / display device 3 that an abnormality that cannot normally occur has occurred and processing cannot be continued.

If the checksum is successfully verified, that is, if the two checksums match, the activation control unit 44 determines in step S14 that the user program stored in the first user program storage unit 31 and the second user The program is compared with the user program stored in the program storage unit 33. If the two do not match, the activation control unit 44
In S15, the backup processing unit 43 is instructed,
The operator of the control / display device 3 is prompted to make a backup by displaying "no backup" on the liquid crystal display device 13a. The two user programs are compared, for example, by comparing their respective checksums.

In step S16, the start control unit 44 reads the user program from the first user program storage unit 31 regardless of the presence or absence of the backup.
At 17, the user program is developed to create an instruction list and stored in the instruction list storage unit 32 of the main memory 11d.

When the instruction list corresponding to the user program is stored in the instruction list storage unit 32 by the processing of S11 to S17, the control /
The display device 3 shifts to the normal operation state, and controls each device 2a by repeating the processing of S1 to S6 shown in FIG. 3 as described above.

On the other hand, when the comparison in S11 fails, it indicates that the contents of the SRAM 11c have been lost. In this case, the activation control unit 44 determines that F
The user program is read from the second user program storage unit 33 of the EPROM 11b, and in S22, "minor abnormality" is displayed on the liquid crystal display device 13a, so that the operator of the control / display device 3 runs out of battery. To notify that the contents of the SRAM 11c have been lost.

In step S23, the activation control unit 44 sets the ladder flag to "SRAM" and writes a string. Since the string is held until the next time the battery runs out, the control / display device 3 can check whether the battery has run out by referring to the string at each start-up (S11). .

Further, in S24, the activation control unit 44 reads the user program from the second user program storage unit 33 of the FEPROM 11b,
After the storage in the first user program storage unit 31c, the above-described processing from S16 is performed. Thus, the SRAM 11
control / display device 3 even if the contents of
Can read out the user program from the second user program storage unit 33 of the FEPROM 11b, and can start up by itself without communicating with other devices such as the computer 4.

If the ladder flag indicates "FEPROM" in the determination in S12, the activation control unit 4
4 reads the user program from the second user program storage unit 33 by performing the processing after S24. Further, for example, when the user program is not stored in the second user program storage unit 33, for example, in a state in which the second user program storage unit 33 is not backed up, the collation of the string in S11 fails, and the second user program storage unit 33
If you try to read the user program from, the read fails. At this time, the activation control unit 44 displays “no ladder program” in the liquid crystal display device 13a in S32.
Is displayed, and the second user program storage unit 33 is displayed.
Is notified to the operator that no user program is stored. In this case, the operator instructs the control / display device 3 to read the user program from the communication circuit 12, and causes the control / display device 3 to read the user program from another device such as the computer 4.

Here, the processing of S6 shown in FIG. 3 will be described in more detail with reference to FIGS. 8 to 12. That is, the computer 4 connected to the control / display device 3 transmits an online edit request to the control / display device 3 in S41 shown in FIG. In step S42, the computer 4 obtains the password by prompting the user for input or refers to a file in which the password is stored in advance, and transmits the password to the control / display device 3. The transmission timing may be transmitted, for example, together with the online edit request, or may be transmitted in response to a request from the control / display device 3 that has received the online edit request.

On the other hand, in the control / display device 3, when the communication processing unit 41 receives the online edit request in S51 shown in FIG. 5, the program editing unit 42 starts operating. Further, in S52, the program editing unit 4
2 receives the password from the computer 4 and executes S53.
, The received password is collated, for example, by comparing it with a regular password stored in advance. If the collation is successful, the program editing unit 42 sends an OK response indicating successful collation in step S54 to the computer 4.
Send to If the verification fails, an NG response indicating the verification failure is transmitted to the computer 4 in S55.

Also, the computer 4 executes S4 shown in FIG.
In step S3, when an OK response is received from the control / display device 3, in step S44, as shown in FIG.
It is displayed as a ladder diagram, and the user of the computer 4 is prompted to edit. When the NG response is received in S43, the computer 4 stops the online editing process. The ladder program displayed as a ladder diagram may be read from a file of the computer 4 or may be read from the control / display device 3.

For example, as shown by the broken line in FIG. 10, when the user adds a contact c to the circuit to be edited and instructs the finalization of the editing and the transmission to the control / display device 3, the computer 4 causes the editing finalizing circuit , A necessary online edit command is identified and transmitted to the control / display device 3. In this case, in the ladder diagram, between the contact point a and the output circuit b,
A new contact c has been added, and the ladder program has the contact c between the commands “LD a” and “OUT b” corresponding to the contact a and the output circuit b, as shown in FIG. New command "AND
Therefore, the computer 4 needs to add the command “AND c” between both commands “LD a” and “OUT b”, that is, at address 2.
To add it. In this case, since the contact point c corresponds to the new device, a command indicating addition of a variable that associates the actual device address of the device with the identifier c on the ladder program is issued. In response, the program editing unit 42 of the control / display device 3 changes the instruction list. Thus, in the process of S2 (see FIG. 3) performed after the change of the instruction list, the device control unit 36 can control each device 2a based on the changed instruction list. In the present embodiment, the identifier on the ladder program is associated with the device address via a variable. Therefore, when the device address of a certain identifier is changed, the change of the device address can be reflected in all portions of the ladder program corresponding to the identifier only by changing the device address of the variable corresponding to the identifier.

Here, in the present embodiment, as described above, as a command that can be issued by the computer 4 during online editing, a line addition command for adding one line of a ladder circuit between designated rungs, and a variable addition command In addition to the above, a line replacement command for editing a ladder circuit of an existing line, a line deletion command for deleting an existing line, a label addition command for adding a label for program control such as a jump destination of a JMP command in a ladder program, and
A subroutine addition command for instructing addition of a series of subroutines is defined. In this embodiment, the variable is not deleted even when the row delete command is issued. The variable addition command is issued only when it becomes necessary by a line addition command or a line replacement command.

If these commands are prepared, it is possible to sufficiently cope with the use of online editing, that is, the use of changing a part of the ladder program without interrupting the control of the device 2a. Furthermore, the above command is compared with the case of transmitting the entire ladder program,
The amount of data to be transmitted is small, and processing can be sufficiently performed in a period provided for display update, such as a device control pause period (for example, about 20 ms) shown in FIG.

In S44 shown in FIG. 8, when the user changes the ladder diagram and notifies the user of the editing decision, the computer 4
Sequentially issues an online edit command corresponding to the change to the control / display device 3. On the other hand, the control / display device 3 updates the contents of the instruction list storage unit 32 according to the online edit command, and controls the device 2a based on the changed instruction list. Further, when the user of the computer 4 can confirm that the instruction list has been correctly changed by, for example, the behavior of the device 2a or a response from the control / display device 3, the user edits the next part to be edited online.

When the online editing in S44 is completed, in S45, the computer 4 stores the edited circuit in a storage device provided in its own device such as a hard disk, and in S46,
The edited circuit is transferred to the control / display device 3.

On the other hand, when receiving the packet indicating the ladder program (user program) in S61 shown in FIG. 12, the program editing unit 42 of the control / display device 3 generates a checksum in S62, and in S63, the SRAM 11c The user program is written in the first user program storage unit 31 of the first embodiment. Further, in S64, as in S23 shown in FIG. 7, the ladder flag is set to "S".
RAM "and write a string.

The computer 4 executes S4 shown in FIG.
In step 7, a notification indicating the completion of the transfer to the SRAM and a notification prompting the user to copy the FEPROM 11b to the second user program storage unit 33 are displayed on the display screen of the own device. Note that the computer 4 may instruct the control / display device 3 to cause the liquid crystal display device 13a of the control / display device 3 to display a message prompting copying.

In the above description, a case has been described in which a user program is already stored in the control / display device 3 and a part of the user program is changed by online editing. For example, when a user program or an I / O driver for controlling the device 2a via the I / O unit 15 is not stored in the control / display device 3, the processing in FIGS. Will be That is, S71 of FIG.
, The computer 4 transmits a download request to the control / display device 3 in response to a user instruction or the like.
Further, similarly to S42 shown in FIG. 8, the computer 4
Submit your password. On the other hand, when the communication processing unit 41 of the control / display device 3 receives the download request in S81 shown in FIG. 14, the activation control unit 44 receives the download request in S82 and S83, similarly to S52 and S53 shown in FIG. Verify password. If the collation is successful, the activation control unit 44 sets the ladder flag to “FEPROM” in S84, writes a string in the SRAM 11c, and returns an OK response indicating successful collation in S85. On the other hand, if the verification in S83 fails, the activation control unit 44 returns an NG response to the computer 4 via the communication processing unit 41 (S86).

On the other hand, the computer 4
When an OK response is received as a password verification result in 73, in S74, in preparation for off-line transfer, for example, the user is prompted to select a necessary I / O driver, and the stored I / O driver is selected.
An I / O driver to be transferred to the control / display device 3 is selected from the O driver group. Further, a user program to be transferred to the control / display device 3 is also selected.

When the preparation for offline transfer is completed in S74 and the data to be transferred is determined, in S75,
The computer 4 sends these data to the control / display device 3
To the start control unit 4 of the control / display device 3
4 is a FEP for the I / O driver and the user program.
Write to the ROM 11b.

Here, in the control / display device 3, the ladder flag is set to "FEPROM" in S84 of FIG. 12, and the string is also written in the SRAM 11c. Therefore, the next time the control / display device 3 starts up, the processes after S11, S12 and S24 shown in FIG. 7 are performed, and the startup control unit 44
The user program is read from the second user program storage unit 33 of 1b.

In the above description, the control / display device 3 having both the function as a PLC and the function as a programmable display has been described as an example. However, during online editing, the volatile memory such as the main memory 11d or the SRAM 11c is used. FEPR after online editing
With a configuration that updates a user program stored in a non-volatile memory such as the OM 11b, substantially the same effects can be obtained even when applied to a control device such as a PLC.

However, when a display function is provided as in the present embodiment, a time is provided for display update processing after executing the user program. Therefore, by editing online during this time,
Variations in scan time due to online editing can be suppressed. Furthermore, when a display function is provided, by using the display function, it is possible to prompt the operator to update the user program without adding a new display unit.

In the present embodiment, the ladder program created / edited by the ladder editor has been described as an example of the user program, but the present invention is not limited to this. For example, the computer 4 may create a user program based on a flowchart, or may directly write a source code of an instruction code.
In any case, if the control / display device 3 repeatedly executes the user program, substantially the same effect can be obtained. However, editing with a symbol, such as a ladder editor, is easier for a user who has not written the source code.

[0070]

As described above, the control device according to the first aspect of the present invention provides a nonvolatile memory, a volatile memory, and an online edit for changing a user program in the volatile memory between executions of the user program. Means, writing means for storing the user program of the volatile memory in the non-volatile memory, and if the volatile memory could not hold the user program normally,
A read control unit that reads a user program from the nonvolatile memory.

According to the above configuration, since the online editing means changes the user program in the volatile memory, even if the user program is frequently changed during the online editing, the control device does not hinder the user program without any trouble. Can be changed. Further, when an accident such as a power failure or running out of battery occurs, and the volatile memory cannot hold the user program, the read control unit reads the user program from the nonvolatile memory, so that the control device communicates with the external device. Control of the device can be started without the need. As a result, despite the fact that the user program can be edited online, even if the above-mentioned accident occurs, the user program can be securely and securely retained, and the time and effort required to recover from the accident can be reduced. Play.

As described above, in the control device according to the second aspect of the present invention, in the configuration of the first aspect, the online editing means includes an instruction list generated by expanding a user program during online editing. After the online editing is completed, a user program before being loaded into the instruction list is received from the external device, and stored in the battery-backed area of the volatile memory.

In the above configuration, during online editing, the instruction list is changed. When the online editing is completed, the user program before expansion is received from the external device and stored in the volatile memory.
This has the effect of reducing the amount of computation during online editing and storing the user program. Further, since the area for storing the user program before the development is backed up by a battery, the user program can be retained even if the power is interrupted while the writing means is writing the user program to the nonvolatile memory. Play.

As described above, the control device according to the third aspect of the present invention has the following features.
When the online editing unit changes the user program in the volatile memory, the online editing unit includes a notification unit that notifies a user to update the user program in the nonvolatile memory, and the writing unit responds to an instruction from the user. Thus, a user program is written into the nonvolatile memory.

Therefore, although the contents of the non-volatile memory can be updated at the point of time desired by the user of the control device, the effect of preventing forgetting to update can be prevented.

According to a fourth aspect of the present invention, as described above, in the configuration of the first, second or third aspect of the present invention, the state of the device is changed while the device control means repeatedly executes the user program. According to the display means for updating the display screen, when performing online editing, in preference to the display update processing by the display means,
The online editing means is provided with an execution control means for changing a user program.

In the above configuration, since the control device has the display means, a period for the display means to update the screen is provided between the device control means repeatedly executing the user program. Further, the execution control means changes the user program prior to display update processing during online editing. Therefore, without significantly changing the execution cycle of the user program,
This has the effect of being able to edit online.

As described above, the recording medium according to the fifth aspect of the present invention has a rewritable nonvolatile memory and a volatile memory whose writing speed is faster than that of the nonvolatile memory, and can communicate with an external device. A computer-readable storage medium storing a program for causing a computer to operate as the control device according to claim 1.

When a program is read from the recording medium having the above configuration and executed by the computer, the computer operates as the control device according to the first aspect.
Therefore, although the user program can be edited online, it is possible to reduce the time and effort required to recover from an accident such as a power failure or running out of battery.

[Brief description of the drawings]

FIG. 1 illustrates one embodiment of the present invention, and is a block diagram illustrating a main configuration of a control system.

FIG. 2 is a block diagram illustrating a hardware configuration of a control / display device in the control system.

FIG. 3 is a flowchart showing an operation of the control / display device during a normal operation.

FIG. 4 is an explanatory diagram showing an example of a screen displayed by a control / display device when instructing to store a user program stored in the SRAM in a FEPROM.

FIG. 5 is an explanatory diagram showing another example of a screen displayed by the control / display device when instructing to store a user program stored in the SRAM in a FEPROM.

FIG. 6 is an explanatory diagram showing an example of a screen displayed by a control / display device while a user program stored in the SRAM is stored in a FEPROM.

FIG. 7 is a flowchart showing an operation when the control / display device is activated.

FIG. 8 is a flowchart showing in detail the operation of the computer at the time of online editing.

FIG. 9 shows the operation of the control / display device,
It is a flowchart which shows the operation | movement at the time of starting an online edit in detail.

FIG. 10 is an explanatory diagram showing an example of a user program displayed on a computer during online editing.

FIG. 11 is an explanatory diagram showing an example of an instruction list changed by online editing.

FIG. 12 is a flowchart showing an operation of the control / display device and showing an operation when storing a user program transmitted at the end of online editing.

FIG. 13 is a flowchart showing the operation of the computer at the time of initial setting.

FIG. 14 is a flowchart showing the operation of the control / display device at the time of initial setting.

[Explanation of symbols]

Reference Signs List 3 control / display device (control device) 4 computer (external device) 11 memory unit (storage means) 11b FEPROM (non-volatile memory) 11c SRAM (volatile memory) 11d main memory (volatile memory) 36 device control unit (device) Control means) 37 display / operation processing section (display means) 38 execution control section (execution control means) 42 program editing section (online editing means) 43 backup processing section (writing means; notification means) 44 activation control section (reading control means) )

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B018 GA04 HA04 LA06 NA03 NA06 QA05 5B076 DF10 EA17 5H220 BB12 CC07 CX01 CX04 DD04 EE08 FF02 FF03 JJ12 JJ24 JJ38 JJ42

Claims (5)

[Claims] 1. A device control means for controlling a device by repeatedly executing a user program stored in a storage means, and executing the user program in response to an instruction from an external device while repeatedly executing the user program. In a control device having online editing means for changing, the storage means includes a rewritable nonvolatile memory, and a volatile memory whose writing speed is faster than that of the nonvolatile memory. Writing means for changing the user program stored in the volatile memory and storing the user program stored in the volatile memory in the non-volatile memory; and the volatile memory could not normally hold the user program. Read the user program from the nonvolatile memory. A control device comprising: 2. The method according to claim 1, wherein at least a part of the volatile memory is backed up by a battery, and the device control means stores an instruction list in which a user program is expanded in the volatile memory, executes the instruction list, and executes the instruction list. The online editing means changes the instruction list during online editing, and after the online editing, from the external device,
2. The control device according to claim 1, wherein the control unit receives the user program before being developed into the instruction list and stores the user program in a battery-backed area of the volatile memory. 3. An informing means for informing a user to update the user program in the non-volatile memory when the on-line editing means changes the user program in the volatile memory; 3. The control device according to claim 1, wherein a user program is written to the nonvolatile memory in response to an instruction from the control device. 4. While the device control means repeatedly executes a user program, the device control means responds according to the state of the device.
Display means for updating the display screen; and execution control means for causing the online edit means to change a user program, prior to display update processing by the display means when online editing is performed. The control device according to claim 1, 2 or 3. 5. A program that has a rewritable nonvolatile memory and a volatile memory whose writing speed is faster than the nonvolatile memory, and stores a program for operating a computer capable of communicating with an external device as a control device. A recording medium, wherein the user program stored in the volatile memory is repeatedly executed to control a device to be controlled, and the user program stored in the volatile memory is controlled according to an instruction from the external device. Online editing means for changing the user program, writing means for storing the user program stored in the volatile memory in the non-volatile memory, and the non-volatile memory if the volatile memory cannot normally hold the user program The computer as read control means for reading a user program from the computer Recording medium on which the program to operate is recorded.