JPH0870336A - Programmable controller - Google Patents

Abstract

PURPOSE: To automatize communication rate change by connecting a peripheral equipment A at a specified communication rate (a), transferring data at a rate (b) in response to the equipment A when the change of the rate (a) → (b) is requested from the equipment A and returning to the rate (a) again after transfer is ended. CONSTITUTION: A PC 10 communication-connects with a personal computer 20 with the communication rate of a baud rate(BR) (a), the personal computer 20 judges that the BRa is communicable, receives the transferred data and stores them in a memory 12 and communication is ended. Then, the PC 10 communication-connects with the personal computer 30 at the BRa, and when it is judged that the communication is possible at the BRb faster than the BRa, the personal computer 30 transmits a BR change instruction. The PC 10 which receives the instruction changes the BRa to (b), communication-connects with the personal computer 30, receives the data transfer request of the personal computer 30 and transfers the data. After the transfer is ended, the PC 10 and the personal computer 30 return the BRb to the initial BRa and end the communication. Thus, data transfer is automatically turned to the optimum BR and transfer time is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller (hereinafter referred to as a PC), and more particularly to a high speed and easy data communication between a PC peripheral device such as a personal computer and a PC device main body.

[0002]

2. Description of the Related Art In a conventional PC, a ladder circuit diagram is written in accordance with desired operation control of equipment and a relay circuit is formed according to the circuit diagram. Recently, however, PCs have become microcomputerized, and ladder circuits have been designed on a dedicated programming device or personal computer monitor, and the program resulting from the design has been converted to a microcomputer.
The program is transferred to the main body of the C device and executed on the PC. Conversely, transfer the program on the PC to the PC and display it on the PC monitor.
Processing such as correction is also performed.

In such a case, serial communication is generally used as data transfer between a PC and peripheral devices, and RS232C and RS422, which are serial communication standards, are used in consideration of connection with peripheral devices such as personal computers. ing. In this type of serial communication, it is necessary to match the communication speed (baud rate) on the PC side with the communication speed on the peripheral device side, so select the data communication speed for the PC device body according to the peripheral device. PC is available
The communication speed of the device body was manually changed by a changeover switch or a software switch.

[0004]

Since high speed processing is required due to improvement in productivity, high speed transfer is desired in data communication. However, as shown in FIG. 7, one PC
Multiple peripheral devices 2 and 3 (two in FIG. 7)
There was the following problem when was connected. That is,
The communication speed at which the peripheral device 2 can communicate is the baud rate a [bp
s], the peripheral device 3 can communicate with both the baud rate a and the baud rate b higher than the baud rate a, and when the peripheral device 2 is used to perform data communication with the PC 1. It is desirable to perform at the baud rate a, while at the time of performing data communication to the PC 1 using the peripheral device 3, it is desirable to perform at the baud rate b. That is, PC1
In order to perform the data transfer between the peripheral device 2 and the peripheral devices 2 and 3 at the optimal (communicable highest speed) communication speed, the worker
There is a problem that the communication speed of the PC 3 is known and it is necessary to manually change the communication speed of the PC 1 according to the communication speed. Further, the PC 1 needs to switch the communication speed to the baud rate a when communicating with the peripheral device 2 and to the baud rate b when communicating with the peripheral device 3, which causes a troublesome task of switching the communication speed. Occurred. Further, there is a problem in that normal data communication cannot be performed if the communication speed switching operation is mistaken.

[0005]

As shown in FIG. 1, the configuration of the invention for solving the above-mentioned problems is as follows. In a programmable controller 100 to which a peripheral device 200 for transferring data by serial communication is connected, The initial baud rate connection means 101 for communication connection to the peripheral device 200 at a preset specific communication speed, and the baud rate change command for requesting a change in the communication speed are the peripheral device 2
Baud rate change determining means 102 for determining whether or not it is transmitted from 00, and the peripheral device 2 when the baud rate change determining means 102 receives the baud rate change instruction.
00, and then the baud rate changing means 103 for changing the communication speed to the communication speed required by the peripheral device 200, and the peripheral device 200 which has received the response, changes the communication speed, and then the peripheral device. And a data transfer means 104 for transferring data to and from 200.

In the second aspect, in addition to the above-mentioned structure, a baud rate initialization means for changing the communication speed to the specific communication speed after the data transfer means 104 completes the data transfer with the peripheral device 200. It is composed of 105.

[0007]

[Function] Now, the peripheral device 200 is connected to the PC100 by the RS23.
It is connected via 2C or the like and is in a state where serial communication is possible. First, the PC 100 is communicatively connected to the peripheral device 200 by the initial baud rate connection unit 101 at a specific communication speed set in advance.

Next, the baud rate change determination means 102 determines whether or not the peripheral device 200 has transmitted a baud rate change command. When the PC 100 receives the baud rate changing command, the baud rate changing means 103 sends a response to the peripheral device 200 to confirm that the baud rate changing command has been received. After that, the communication speed of the PC 100 is requested by the baud rate changing command. Change to communication speed. Usually, in order to speed up the data transfer, the communication speed is changed to a higher communication speed than the communication speed at the initial baud rate connection means 101. Further, the peripheral device 200 receiving the response changes the communication speed to the PC 100 by the baud rate change command, and the PC 100 and the peripheral device 200 are changed.
Set to connect with the changed communication speed.
With the communication speed changed, the data transfer means 10
4, the PC 100 transfers data with the peripheral device 200.

Further, in the PC of claim 2, after the above-mentioned data transfer is completed, the baud rate initialization means 105 restores the communication speed to the specific communication speed and terminates the data communication. .

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is an overall configuration diagram of the PC and its peripheral devices according to the present embodiment. Reference numeral 10 is a PC, which is composed of an arithmetic unit 11, a memory 12, and an interface 13. A sequence program executed by the PC 10 is stored in the memory 12. A display device 15 and an input device 16 are connected to the interface 13, and a sequence program can be created and modified in the PC 10 itself. In addition, the personal computer 20 and the personal computer 30, which are peripheral devices of the personal computer 10, are connected to the interface 13 via the communication module 14 via the communication cable 4.
2 and 43 are connected, and serial communication is possible.

The personal computer 20 is a peripheral device that creates a sequence program to be executed by the PC 10, and transfers the created sequence program to the PC 10. The personal computer 30 is a peripheral device that reads the sequence program in the PC 10 and displays the ladder circuit on the monitor from the sequence program. However, the functions and performances of the personal computer 20 and the personal computer 30 are different, and the communicable communication speed of the personal computer 20 is only the baud rate a BPS, and the communicable communication speed of the personal computer 30 is higher than the baud rate a and the baud rate a. It is possible at baud rate b.

Next, the operation of this embodiment will be described. 3 is P
FIG. 4 is a flow chart showing the operation of C10, FIG. 4 is a flow chart showing the operation of personal computers 20 and 30, FIG. And PC
FIG. 3 is a diagram showing a relationship between data communication and baud rates among 10 terminals. It should be noted that the PC and peripheral devices (PC 20,
0) is a baud rate a at which both the personal computer 20 and the personal computer 30 can communicate.

First, using the personal computer 20, the personal computer 2
Data transfer of the sequence program from 0 to the PC 10 will be described. However, it is assumed that a sequence program for the PC 10 created by the personal computer 20 is stored in a memory (not shown) in the personal computer 20. In steps 501 and 601, the PC 10 and the personal computer 20 are communicatively connected with the baud rate a as the communication speed. Next, the peripheral device 20 determines in step 602 whether or not to change the communication speed. In this case, since the communication speed of the personal computer 20 is only the baud rate a and the communication speed is not changed, the process proceeds to step 607 and the transfer of desired data (sequence program) is started. Then, the PC 10 does not receive the baud rate change command in step 502, and therefore proceeds to step 505 to receive data (point A to point B in FIG. 5). P
The C10 stores the received data in the memory 12, and when the reception of the data is completed, in step 506, the response indicating that the data reception is completed is transmitted to the personal computer 20 (point C to point D in FIG. 5). Then, in step 507, the PC 10 determines whether the current communication speed is the baud rate a. In this case, since the communication speed is the baud rate a, the communication ends in this state.

Further, the personal computer 20 performs P at step 608.
The response transmitted from C10 is received, and it is determined in step 609 whether or not the data transfer is normally performed according to this response. If an abnormality occurs, the process proceeds to step 612, error processing such as displaying a communication abnormality is performed, and the processing ends abnormally. On the other hand, step 609
When it is determined that the data transfer is normally performed, the process proceeds to step 610, and it is determined whether the current communication speed is the baud rate a. In this case, the communication speed is the baud rate a, so the communication ends.

Next, using the personal computer 30, the PC 10
The data transfer of the sequence program from the personal computer to the personal computer 30 will be described. However, PC2 is PC2
It is assumed that the sequence program created by 0 or the sequence program created by the PC 10 is stored in the memory 12. Step 501 and Step 60
By 1, the PC 10 and the personal computer 30 are communicatively connected with the communication speed as the baud rate a. Next, the personal computer 30 determines in step 602 whether to change the communication speed.
In this case, the personal computer 30 can communicate at the baud rate b which is faster than the baud rate a.
A baud rate change command is transmitted to C10 (point E to point F in FIG. 6). Then, the PC 10 receives the baud rate change command in step 502, and in step 503.
A baud rate change response indicating that the baud rate change command has been received is transmitted to the personal computer 30 (see FIG. 6).
Midpoint G to point H). Then, after this, in step 504, the communication speed of the PC 10 is changed to the baud rate b (FIG. 6).
Midpoint G ').

The personal computer 30 receives the baud rate change response at step 604 (point H in FIG. 6), and this response determines at step 605 whether the baud rate change command is normally transmitted. If the baud rate change command is normally communicated, the process proceeds to step 606, and if the communication is abnormal, in step 613, error processing such as communication error display is performed and the process ends abnormally. Then, in step 606, the communication speed of the personal computer 30 is changed to the baud rate b (point H ′ in FIG. 6). As a result, the PC 10 and the PC 30 are in the state of communication connection at the changed baud rate b.

Subsequently, in step 607, the personal computer 3
0 transmits a data request command requesting data (sequence program) transfer to the PC 10 (I to point J in FIG. 6). Then, the PC 10 receiving the data request command in step 505 transmits the data to the personal computer 30 in step 506 as a response to the reception of the data request command (point K to point L in FIG. 6). Further, the PC 10 that has completed the data transmission determines in step 507 whether the current communication speed is the baud rate a. In this case, since the communication speed is the baud rate b, the process proceeds to step 508, and the communication speed of the PC 10 is changed to the baud rate a (point K ′ in FIG. 6).

On the other hand, the personal computer 30 receives the data as the response in step 608, and it is determined in step 609 whether the data has been normally received from this response. If the data transfer is normally performed, the process proceeds to step 610, and if there is an error in the data transfer, the process proceeds to step 612, and error processing such as communication error display is performed to terminate abnormally. And
When the process proceeds to step 610, it is determined whether the current communication speed is the baud rate a. In this case, since the communication speed is the baud rate b, the process proceeds to step 611, the communication speed of the personal computer 30 is changed to the baud rate a, and the communication is ended (point L ′ in FIG. 6).

In the above-described embodiment, when the communication speed of the PC 10 and the personal computer 30 is returned to the baud rate a after the data transfer, the PC 10 and the personal computer 30 recognize that the data transfer is completed individually. However, from step 603 to step 60
The baud rate change command may be transmitted from the personal computer 30 to the personal computer 10 in the same process as in 6.

Further, in the above-mentioned embodiment, although the communication abnormality is displayed and the processing is terminated abnormally as the error processing of step 612, the command or data may be retransferred. Further, in the above-described embodiment, two personal computers 20 and 30 are connected as peripheral devices,
The peripheral device is not limited to the personal computer as long as the PC 10 requires data communication.

[0021]

As described above, in the PC of the present invention, regardless of the peripheral device to be connected, the operator can automatically transfer the data without being aware of the communication speed and optimize the peripheral device (communication is possible). Since it can be performed at the highest communication speed, the data transfer time can be shortened.

In addition, like the PC described in claim 2,
By returning to the initial specific communication speed after data transfer, even if a plurality of peripheral devices having different communication speeds that can be communicated are connected, the operator does not have to manually switch the communication speed on the PC side, and a switching malfunction occurs. Communication error due to is eliminated. Furthermore, since the PC and the peripheral device are communicatively connected at a preset specific baud rate, and then the baud rate of both the PC and the peripheral device is changed to a high speed, the device that detects the baud rate of the peripheral device side by the PC during communication connection There is an effect that the program need not be provided in the PC and can be realized at low cost.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a claim of the present invention.

FIG. 2 is an overall configuration diagram of a PC and its peripheral devices according to an embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of the PC in the embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the personal computer according to the embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between data communication and communication speed between a PC and a PC in the embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between data communication and communication speed between a PC and a PC in the embodiment of the present invention.

FIG. 7 is a diagram showing the concept of a conventional PC and its peripheral devices.

[Explanation of symbols]

 10 PC 11 arithmetic unit 12 memory 13 interface 14 communication module 20, 30 personal computer 42, 43 communication cable

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Otsu 1-1 Asahi-cho, Kariya city, Aichi Toyota Koki Co., Ltd. Within the corporation

Claims (2)

[Claims] 1. A programmable controller to which a peripheral device for transferring data by serial communication is connected, and an initial baud rate connecting means for making a communication connection to the peripheral device at a preset specific communication speed,
Baud rate change determining means for determining whether or not a baud rate change command requesting a change in communication speed is transmitted from the peripheral device, and when the baud rate change command is received by the baud rate change determining means, the peripheral device is notified to the peripheral device. Between the peripheral device receiving the response and the baud rate changing means for changing the communication speed to the communication speed required by the peripheral device, and after the peripheral device receiving the response changes the communication speed. And a data transfer unit that transfers the data. 2. The programmable controller according to claim 1, further comprising a baud rate initialization means for changing the communication speed to the specific communication speed after the data transfer means completes the data transfer with the peripheral device. A programmable controller characterized by being provided.