JPH05119813A - Communication unit for programmable controller and its communication method - Google Patents

Abstract

PURPOSE:To improve operability, to simply generate a sequence program for transmission and to quickly execute a transmission processing by registering transmitting data and also, transmitting plural registered transmitting data by a single transmission request. CONSTITUTION:The communication unit 1 has a shared memory 2 capable of making access from a CPU unit for controlling the whole programmable controller and is provided with a function for transmitting designated data to the shared memory 2 by the CPU unit. Also, the unit is provided with a registration data memory 5 for registering transmitting data designated by the shared memory 2 and the shared memory 2 provided with at least a registered data designating memory 4 for storing registration No., registered data length and registered data, a registration request flag 41 for showing a registration request of transmitting data, a registration No. designating memory 6 for designating transmitting registered data and a registered data transmission request flag 61 for transmitting the registered data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication unit of a programmable controller having a shared memory accessible from a CPU unit and having a function of transmitting data designated by the CPU unit to the shared memory, and a communication method thereof. It is a thing.

[0002]

2. Description of the Related Art FIG. 9 shows an example of a system configuration in the case of transmitting data to a peripheral device of a programmable controller. In FIG. 9, 10 is a CPU unit for controlling the entire programmable controller, and 1 is data. 2 is a shared memory of the communication unit 1 accessible from the CPU unit 10, 11 is a peripheral device for outputting data, and 12 is a communication cable connecting the communication unit 1 and the peripheral device 11.

FIG. 10 shows an example of the memory configuration of the shared memory 2 in the communication unit 1, where 3 is a transmission data memory and 31 is a transmission request flag.

FIG. 11 shows an example of the structure of the transmission data memory 3, in which 3a is a transmission data length and indicates that 20 characters of data are transmitted. 3b is transmission data, 1
A character code that represents one character enclosed by a pair of """is entered. Here, "" is a blank character (blank code),
““ ↓ ”represents a line feed code.

FIG. 12 shows an output example assuming that the peripheral device 11 shown in FIG. 9 is a printer.
“A” is a frame indicating an output end, and the scales at the upper end and the left end indicate one character. 10b shows a row and 10c shows a column. 10
d1 to 10d6 are examples in which the output character string is predetermined (fixed data), and 10e are examples in which the output character string is not predetermined (changing data). FIG. 13 is a flowchart showing the operation of the transmission process in the communication unit 1.

Next, the operation will be described. In the programmable controller system configured as shown in FIG. 9, data output from the CPU unit 10 to the peripheral device 11 such as a printer is once output to the communication unit 1 having a communication function with the peripheral device 11. Is executed by the communication unit 1 transmitting the data to the peripheral device 11 via the communication cable 12.

Transmission data is created from the CPU unit 10 on a device memory (not shown) that can be accessed by the sequence program, and the transmission data length 3a and the transmission data 3b are stored in the transmission data memory 3 of the shared memory 2 in the communication unit 1. Write as shown in FIG. Figure 1
In the example shown in FIG. 1, the transmission data length 3a is 20 characters, and the transmission data 3b is “blank, blank, ..., Ki, yo,
C, line break ".

Next, at the timing of transmission, the sequence program sends a transmission request flag 31 to the communication unit 1.
Is set and the transmission request is executed. Here, the communication unit 1 executes the processing shown in the flowchart of FIG. The communication unit 1 determines whether or not there is a transmission request (S
1) When it is determined that the transmission request is accepted, the transmission data length 3a and the transmission data 3b of the transmission data memory 3
Check the contents necessary for import transmission (S
2). If it is determined that there is no error, the transmission data 3b is sequentially transmitted from the beginning in the order of "blank, blank, ..." (S
3). On the contrary, if it is determined that there is an error, error processing is executed (S4). When the data transmission of 20 characters for the transmission data length 3a is completed, the communication unit 1 completes the transmission and resets the transmission request flag 31 to cancel the transmission request (return to the initial state) (S5). The transmission process of the communication unit 1 is now completed, and the next process is performed.

Further, the CPU unit 10 knows that the transmission process of the communication unit 1 is completed by this, and the next transmission request can be accepted. When it is desired to continue transmission, the CPU unit 10 confirms that the transmission request flag 31 has returned to the initial state, transmits the next data, sets it in the transmission data memory 3, and makes a transmission request.

For example, let us consider a case in which some numerical value changes are output to a printer in a table as shown in FIG. An example of transmission data for outputting the second row of this table is shown in FIG.
It is the transmission data 3b shown in FIG. In this way, one line may be transmitted as one transmission data. But 1
For the 1st, 3rd, 4th, ... Lines, or the 7th, 9th, 11th, ... Lines in which the data of the lines are exactly the same, the same data is set and transmitted in each case by the sequence program. For example, after the data of the sixth line is created, set, and transmitted, the data forming the ruled line of the seventh line is created, set, and transmitted. Next, after creating, setting and transmitting the data of the 8th line, all the data having the same ruled lines as those of the 7th line in the 9th line are also newly created, set and transmitted. 10th line, 11
The same applies to the line. However, in the case of the same data, the data can be created once and stored in the device memory or the like, but all of the stored data must be set in the transmission data memory 3.

Also, when there are some same parts in one line (same pattern) as in the sixth, eighth, tenth lines,
For example, the sixth line, the eighth line, and the tenth line must be created, set, and transmitted once for each line as separate data. For example, in the case of the 6th row, 10d1 and 10
One line of data is created in order of d2, 10d3, ..., Set, and transmitted. Alternatively, one line is divided into several parts according to the pattern, the same pattern is stored in the device memory, etc., and transmission data is created in units of divided character strings, set and transmitted. For example, in the 6th line If there is, it is divided into 10d1, 10d2, 10d3 ..., 10d1 is first set and transmitted, then 10d2 is set and transmitted ..., and transmission in character string units is repeated.
Even when the changing character strings such as the 8th and 10th lines are included, the method of repeating the transmission in the character string units is performed.

In addition, as other reference technical documents related to the present invention, for example, "Facsimile response device" disclosed in Japanese Patent Laid-Open No. 63-131772, Japanese Patent Laid-Open No. 63-
There is a "facsimile device" disclosed in Japanese Patent No. 284971 and a "facsimile device" disclosed in Japanese Patent Application Laid-Open No. 2-153673.

[0013]

Since the communication unit of the conventional programmable controller having the transmission function can transmit only the transmission data of the designated area in the shared memory as described above, the data of several formats can be transmitted a plurality of times. In the case of transmission, it was necessary to set all the transmission data for each transmission. this is,
For example, in the case of transmitting two or three types of fixed data alternately, all the data must be set every time, and there is a problem that the operability is extremely poor.

In addition, since it is necessary to check whether or not the communication unit can accept each transmission and execute a transmission request, the same data is transmitted many times when the peripheral device is a printer or a CRT. However, even in such a case, there are problems that the program becomes complicated and that the transmission process as the whole sequence program takes time.

The present invention has been made to solve the above-mentioned problems, and registers transmission data, and
By transmitting a plurality of registered transmission data with one transmission request, the operability is improved, a sequence program for transmission can be easily created, and the transmission process of the entire sequence program is executed quickly. An object of the present invention is to obtain a programmable controller communication unit and a communication method thereof.

[0016]

A communication unit of a programmable controller according to the present invention has a shared memory accessible from a CPU unit that controls the entire programmable controller, and data designated by the CPU unit in the shared memory. In the communication unit of the programmable controller having a function of transmitting the registration data memory for registering the transmission data designated by the shared memory and the shared memory, at least the registration number. , A registration data length, a registration data designation memory for storing registration data, a registration request flag indicating a registration request for the transmission data, and a registration number for designating registration data to be transmitted. It is provided with a designated memory and a registration data transmission request flag for transmitting the registration data.

In the communication unit of the programmable controller according to the present invention, the shared memory can specify a plurality of registration data by the sequence program of the CPU unit, and the plurality of registered transmission data are sequentially transmitted according to the contents of the shared memory. Is something that can be done.

A communication method of a communication unit of a programmable controller according to the present invention has a shared memory accessible from a CPU unit that controls the entire programmable controller, and transmits data designated by the CPU unit to the shared memory. In a communication method of a communication unit of a programmable controller having a function, it is determined whether or not a registration request flag is present, and when the registration request flag is present, the registration No. stored in the registration data designation memory is stored. Check the registration data length, registration data, and specify the registration number. Is registered in the registration data memory, the registration request flag is released, and then the presence or absence of the registration data transmission request flag is determined. When the registration data transmission request flag is present, the registration No. Registration No. of specified memory If there is no error, the designated registration No. is checked. Registration data is transmitted and the registration data transmission request flag is cleared.

A communication method of a communication unit of a programmable controller according to the present invention has a shared memory accessible from a CPU unit that controls the entire programmable controller, and transmits data designated by the CPU unit to the shared memory. In a communication method of a communication unit of a programmable controller having a function, it is determined whether or not a registration request flag is present, and when the registration request flag is present, the registration No. stored in the registration data designation memory is stored. Check the registration data length, registration data, and specify the registration number. Is registered in the registration data memory, the registration request flag is released, and then the presence or absence of the registration data transmission request flag is determined. When the registration data transmission request flag is present, the counter is set to 1 and the registration No. Nth registration number of the designated memory. If there is no error, the registration number. Nth registration N in the specified memory
o. The registration data transmission request flag is canceled and the registration data transmission request flag is canceled when the registration data is -1.

[0020]

In the communication unit of the programmable controller and the communication method thereof according to the present invention, a plurality of transmission data designated by the sequence program of the CPU unit are registered in the internal memory. It is possible to register (store) with, and to send the already registered data, the registration No. of the registration data to be transmitted is sent instead of the transmission data. Is specified and a transmission request is made.

Further, in the communication unit of the programmable controller and the communication method thereof according to the present invention, a plurality of registration data to be transmitted can be designated.
Are designated in advance, and a plurality of registration data are all transmitted in the designated order in one transmission request.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a memory configuration of a communication unit. 1 is a communication unit, 2 is a shared memory, 3 is a transmission data memory, 31 is a transmission request flag, 4 is a registration data designation memory, 41 is a registration request flag. 5 is a registration data memory for storing registration data, and 6 is a registration number for specifying registration data to be transmitted. A designated memory, 61 is a registration data transmission request flag, and 100 is a control means for controlling the entire communication unit 1.

2 shows software for each part of the shared memory 2 (transmission data memory 3, transmission request flag 31, registration data designation memory 4, registration request flag 41, registration number designation memory 6, registration data transmission request flag 61). The respective means in the control means 100 for executing the dynamic control are shown. 101 is means for transmitting the transmission data set in the shared memory 2 to the peripheral device 11, 102 is means for accepting the transmission request flag 31 from the sequence program of the CPU unit 10, and 103 is for notifying the CPU unit 10 of completion of transmission. Means for clearing the transmission request flag 31, 104 for storing the transmission data set in the shared memory 2 in the registered data memory 5, 105 for CP
Means for accepting the registration request flag 41 from the sequence program of the U unit 10, 106 is the CPU unit 1
0 is a means for canceling the registration request flag 41 for notifying the registration completion to the registration data registered in the shared memory 2. Means for transmitting according to the designated memory 6,
Reference numeral 108 denotes a means for receiving the registration data transmission request flag 61 from the sequence program of the CPU unit 10, 1
Reference numeral 09 is means for canceling the registration data transmission request flag 61 for notifying the CPU unit 10 that registration data transmission has been completed.

FIG. 3 shows an example of the memory configuration of the registration data designating memory 4, 4a being the registration number. Reference numeral 4b is the registration data length, and 4c is the registration data. FIG. 4 shows an example of the memory configuration of the registration data memory 5, 501
a and 501b, registration No. 1 shows the data. 501a
Is the registration number. The registration data length of No. 1 and 501b is the registration number.
It is the registration data of 1. Similarly, 502a and 502b are registration numbers. 2 shows the data of registration No. Up to m, that is, m registrations are possible.

FIG. 5 shows the registration number. It is an example showing a memory configuration of the designated memory 6. (A) shows one registration number. (B) shows a plurality of registration numbers. Can be specified. FIG. 6 is a flowchart showing the operation of the registration process in the communication unit 1. 7 and 8 are flowcharts showing the operation of the registration transmission process in the communication unit 1. Here, FIG. 7 shows FIG.
8 is the registration transmission process in the case of FIG. 5, and FIG. 8 is the registration transmission process in the case of FIG.

Next, the operation will be described. First, registration will be described. Registration data is created from the CPU unit 10 on a device memory (not shown) that can be accessed by the sequence program, and the registration data is registered in the registration data designation memory 4 of the shared memory 2 in the communication unit 1. The registration data 4c is written together with 4a and the registration data length 4b as shown in FIG. In the example of FIG. 4a
Is 2, the registered data length 4b is 3 characters, and the registered data 4c is “blank, blank | (vertical ruled line)”. Next, the registration request flag 41 is set in the communication unit 1 by the sequence program at the timing of registration, and a registration request is made.

Here, the communication unit 1 performs the processing shown in the flowchart of FIG. The communication unit 1 determines whether or not there is a registration request (S10), and when the registration request is accepted, the registration number of the registration data designation memory 4 is determined. 4a
Then, the registration data length 4b and the registration data 4c are fetched and the check necessary for registration is performed (S11). When it is determined that there is no error, the designated registration number. Is registered in the registration data memory 5 (S12). On the contrary, if it is determined that there is an error, error processing is executed (S13). Registration to the registration data memory 5 is performed by registering the registration number. When the value of 4a is n '(n' is 2 in FIG. 3), n'of the registered data memory 5 is
The fifth registration data length 50n'a (502 in FIG. 4)
The registration data length 4b is added to the registration data 50n'b in FIG.
In this case, the registration data 4c is transferred to 502b).
With this, the registration is completed, and the communication unit 1 resets the registration request flag 41 to complete the registration and cancels the registration request (returns to the initial state) (S14). The registration process of the communication unit 1 is completed, and the following process is performed.

Further, the CPU unit 10 knows that the registration process of the communication unit 1 is completed and the next registration request can be accepted. When the user wants to continue registering, the CPU unit 10 confirms that the registration request flag 41 has returned to the initial state, and then sets the next data in the registration data designation memory 4 to make a registration request.

Next, the transmission of registered data will be described. The registration number of the shared memory 2 of the communication unit 1 is registered by the sequence program from the CPU unit 10. Designated memory 6
Registration No. Is written as shown in FIG. Figure 5
In the example of (a), the registration number. Is 2. Next, the registration program transmission request flag 61 is set in the communication unit 1 by the sequence program at the timing of transmission, and a registration transmission request is issued. Here, the communication unit 1 performs the process shown in the flowchart of FIG. The communication unit 1 determines whether there is a registration transmission request (S21), and when the registration transmission request is accepted, the registration number. Registration No. of the designated memory 6
Import registration number. Is checked (S22). If it is determined that there is no error, a transmission process for transmitting registration data is performed (S23). Specifically, the registration number. If the value designated in the designated memory 6 is n ′ (n ′ is 2 in the case of FIG. 5A), the n′-th registration data 50n′b (502b in FIG. 4) of the registration data memory 5 Data corresponding to the number of characters set to the registered data length 50n'a (502a in FIG. 4) is sequentially transmitted from the data from the beginning (in the case of FIG. 3, the three characters "blank, blank, |" Send). When the transmission is completed, the communication unit 1 determines that the registration is completed, resets the registration data transmission request flag 61, and cancels the registration transmission request (returns to the initial state) (S25). The registration / transmission processing of the communication unit 1 is completed, and the following processing is performed. If it is determined in step S22 that there is an error, error processing is executed (S24).

Further, the CPU unit 10 knows that the registration transmission process of the communication unit 1 is completed by this, and the next registration transmission request can be accepted. When it is desired to continuously transmit the registration data, the CPU unit 10 confirms that the registration data transmission request flag 61 has returned to the initial state, and then the next registration number. Register No. It is set in the designated memory 6 and a registration transmission request is made.

Next, a second embodiment of the present invention will be described with reference to the drawings. 5 shows the registration number. It is a memory configuration example of the designated memory 6, and (b) is composed of n areas 601 to 60n. Since an end code indicating the end of N is added, a maximum of n-1 multiple registered N
o. Can be specified. FIG. 8 is an operation flowchart of the registration transmission process of the communication unit 1, and FIG.
This is the registration transmission process in the case of.

Next, the operation will be described. In the registration transmission process of the second embodiment, the registration No. Designated memory 6
Is configured as shown in FIG. Can be set up to n-1. Registration No. in which the data you want to send is registered. Register N
o. The items are set in the order of transmission from 601 of the designated memory 6. At this time, the final registration No. Next to the registration number. A final code indicating the end is added. In the example of FIG. 5B, 60
6 is "-1". In this way, the CPU unit 10
Registration No. from the sequence program After setting in the designated memory 6, the registration data transmission request flag 61 is set in the communication unit 1 by the sequence program at the timing of transmission and a registration transmission request is issued.

Here, the communication unit 1 performs the processing shown in the flowchart of FIG. Here, the counter N is the registration N
o. The registration number of the designated memory 6 Is counting what is running. The communication unit 1 determines whether or not there is a registration transmission request (S31), and when the registration transmission request is accepted, first, the counter N is set to 1 (S32),
Registration No. Registration No. of 601 of the designated memory 6 The registration number. Is checked (S33). "-1"
If this is the case, the registration data transmission request flag 61 is reset and the registration transmission request is canceled (returned to the initial state) since the registration transmission is completed (S34). If it is not an error (if it is an error, error processing is executed (S3
7)), from the registration data memory 5 to the registration number. No. indicated by the designated memory 601. , N (in the case of FIG. 5B, N is 1)
Registration data length 50Na (501a in FIG. 4) from registration data 50Nb (501b in FIG. 4) data
The data for the number of characters set in is sequentially transmitted from the beginning (S35). When the transmission is completed, +1 is added to N to set N = 2 (S36), and the next registration number. Registration No. of 602 of the designated memory 6 Is checked, and if it is normal, the registration No. indicated by 602 is displayed. Send the registration data of.

In this way, the registration data is transmitted as 601 → 602 →, and the registration number. Registration N until becomes -1
o. Registration No. in the designated memory 6 The registration data indicated by is transmitted. Registration No. When becomes -1, registration and transmission is completed. The registration / transmission processing of the communication unit 1 is completed, and the following processing is performed. Further, the CPU unit 10 knows that the processing of the communication unit 1 is completed by this, and the next registration transmission request can be accepted. When it is desired to continuously transmit the registration data, the CPU unit 10 confirms that the registration data transmission request flag 61 has returned to the initial state, and then the next registration number. Register the required number of registration numbers. It is set in the designated memory 6 and a registration transmission request is made.

For example, let us consider a case in which some numerical value changes are output to the printer as a table as shown in FIG. When transmitting one line as one transmission data, the line in which the character string of one line is predetermined is registered. 1st, 3rd, 4th, or 1st, 3rd, 4th, ...
For the 11th line and the like, it is sufficient to register one line each. When actually sending, the registration number. The same registration number in the designated memory 6 Repeatedly set, and issue a registration transmission request collectively. For example, the data in the first row is the registration N
o. The data in the second line is the registration number. The data of the 5th line is registered No. 2 and No. 2. If registered in 3, register N
o. It is sufficient to set "1, 2, 1, 1, 3, -1" in the designated memory 6.

When data such as the 6th line in which the same portion is present in one line (the pattern is the same) is to be transmitted, if the data is divided into 10d1, 10d2, ... No. In the designated memory 6, "10d1, 10d2, 1
0d3, 10d4, 10d3 ... "Registration No. And the same character string has the same registration number. Is specified and a registration transmission request may be made. When the character string that changes like the 8th and 10th lines is included, the fixed data is registered and the registration number. The transmission data is transmitted according to the designation of No. 1, and the changing data is transmitted by the conventional transmission method using the conventional transmission data memory 3. In this way, the same data can be sent without having to set it many times.

In the above embodiment, the two processes of the registration process and the registration transmission process are shown, but other processes such as reading and deleting the registered data may be added if necessary.

In the above embodiment, the registration No. Although the contents of the designated memory 6 are the registered transmission data, the transmission data memory 3 may be included and designated. Further, it may be configured such that a plurality of sets of transmission data that are not registered can be set so that they can be designated. Furthermore, the registration number. Was set to "-1" at the end, but another code may be used and the registration number. Alternatively, the number of registration data may be set separately and the registration data of that number may be transmitted.

In the above embodiment, the registration data designation memory 4 and the registration number. Although the designated memory 6 is provided separately, the designated memory 6 may be shared by allowing the processing contents to be designated. At this time, similarly, the registration request flag 41 and the registration data transmission request flag 61 may be shared. Further, although the registration request flag 41 is composed of one flag,
2 controlled by the unit 10 and the communication unit 1, respectively
You may take a handshake with the signal of the book. The same applies to the registration data transmission request flag 61.

In the above embodiment, the registration data designation memory 4 and the registration data memory 5 are configured as shown in FIGS. 3 and 4, but the order may be different or other data may be added. Further, although the registration data length is specified, the final code may be determined and the data immediately before the final code may be transmitted so that the registration data length is not specified. ..

[0041]

As described above, in the communication unit of the programmable controller and the communication method thereof according to the present invention, a plurality of pieces of transmission data are registered in the internal memory in the communication unit. With the registration No. of the registration data to be transmitted instead of the transmission data, the already registered data is registered (stored) with. Since it is configured to specify, when sending data of some certain format multiple times,
Since it is not necessary to set all the transmission data every time the same data is transmitted, the sequence program can be simply written for that amount, and efficient program design can be performed and the operability is improved. There is.

Since a plurality of registration data to be transmitted to the communication unit is designated, the registration number. Since a plurality of registered data are designated and all the registered data are transmitted in the designated order in one transmission request, the sequence program can be simply described, and efficient program design can be performed. Since the number of transmission requests can be reduced compared to the conventional case, the overhead time required for one transmission request can be reduced,
There is an effect that the processing time of the entire transmission can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing a memory configuration of a communication unit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the contents of software control by the control means shown in FIG.

FIG. 3 is an explanatory diagram showing a memory configuration of a registration data designation memory in the communication unit according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a memory configuration of a registration data memory in the communication unit according to the embodiment of the present invention.

FIG. 5 shows a registration No. in the communication unit according to the embodiment of the present invention. It is explanatory drawing which shows the memory structure of a designated memory.

FIG. 6 is a flowchart showing an operation of registration processing in the communication unit according to the embodiment of the present invention.

FIG. 7 is a flowchart showing an operation of registration transmission processing in the communication unit according to the embodiment of the present invention.

FIG. 8 is a flowchart showing the operation of another registration transmission process in the communication unit according to the embodiment of the present invention.

FIG. 9 is a block diagram showing a system configuration when transmitting data to a peripheral device of a conventional programmable controller.

FIG. 10 is an explanatory diagram showing a memory configuration of a conventional communication unit.

FIG. 11 is an explanatory diagram showing a memory configuration of a transmission data memory of a conventional communication unit.

12 is an explanatory diagram illustrating an output example when the peripheral device illustrated in FIG. 9 prints.

FIG. 13 is a flowchart showing a transmission processing operation of a conventional communication unit.

[Explanation of symbols]

 1 Communication unit 2 Shared memory 3 Transmission data memory 4 Registration data designation memory 5 Registration data memory 6 Registration No. Designated memory 10 CPU unit 11 Peripheral device 31 Transmission request flag 41 Registration request flag 61 Registration data transmission request flag 100 Control means

Claims (4)

[Claims] 1. A communication unit of a programmable controller having a shared memory accessible from a CPU unit for controlling the entire programmable controller, the communication unit of the programmable controller having a function of transmitting data designated by the CPU unit to the shared memory, The registration data memory for registering the transmission data designated by the shared memory and the shared memory are at least the registration number. , A registration data length, a registration data designation memory for storing registration data, a registration request flag indicating a registration request for the transmission data, and a registration number for designating registration data to be transmitted. A communication unit of a programmable controller comprising a designated memory and a registration data transmission request flag for transmitting the registration data. 2. The shared memory can specify a plurality of registered data by a sequence program of the CPU unit, and can sequentially transmit a plurality of registered transmission data according to the contents of the shared memory. Communication unit of the programmable controller of 1. 3. A communication method of a communication unit of a programmable controller having a shared memory accessible from a CPU unit for controlling the entire programmable controller, and having a function of transmitting data designated by the CPU unit to the shared memory. In the step S1, the presence or absence of the registration request flag is determined. When the registration request flag is present, the registration N stored in the registration data designation memory is determined.
o. Check the registration data length, registration data, and specify the registration number. Is registered in the registration data memory, the registration request flag is released, the presence or absence of the registration data transmission request flag is determined, and when the registration data transmission request flag is present,
Registration No. Registration No. of specified memory If there is no error, the designated registration No. is checked. Send the registration data of
A communication method for a communication unit of a programmable controller, characterized in that the registration data transmission request flag is cleared. 4. A communication method of a communication unit of a programmable controller having a shared memory accessible from a CPU unit for controlling the entire programmable controller, and having a function of transmitting data designated by the CPU unit to the shared memory. In the step S1, the presence or absence of the registration request flag is determined. When the registration request flag is present, the registration N stored in the registration data designation memory is determined.
o. Check the registration data length, registration data, and specify the registration number. Is registered in the registration data memory, the registration request flag is released, the presence or absence of the registration data transmission request flag is determined, and when the registration data transmission request flag is present,
The counter is set to 1 and the registration number. Nth registration number of the designated memory. If there is no error, the registration number. Nth registration number of the designated memory. Registration data is transmitted, and the registration data transmission request flag is released when the value is -1, the communication method of the communication unit of the programmable controller.