JPS60160439A - Address deciding method for jump with no designation of destination - Google Patents

Abstract

PURPOSE:To reduce the load of a programmer by using a jump instruction having the unlimited length processing conditions with no label showing a destinated jumping destination and eliminating the notice for the relation between the jump instruction and the jumping destination. CONSTITUTION:Instructions 30-32 shown by graphic elements indicate the processing conditions of a jump instruction 33. The instruction 30 makes a CPU detect that the relays shown by operands 301-303 are all set ON. An OR instruction 32 makes the CPU detect that one or more of relays shown by operands 401-403 are set ON. While an AND instruction 31 obtains an AND of execution results of front and back logical arithmetic instructions. Thus it is possible to write the unlimited length processing instruction before a jump instruction in such a flow chart type graphic language.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for determining a jump destination address of a jump instruction with no destination specified in a programmable controller.

[Prior art]

Recently, as microcomputers have become smaller in size, higher in performance, lower in price, and easier to use, the use of microcomputers for various types of control has rapidly increased. Such a control microcomputer integrated with its input/output device is called a programmable controller. This is because by freely changing the programs stored in the memory of the microcomputer, it can be used for various control purposes.

Generally, creating a computer program requires the following steps. First, the processing process of the work to be performed by the computer is analyzed and drawn in a flowchart, and then the code is executed using a programming language according to the flowchart. After being converted into machine language, the program is stored at a predetermined address in the computer's memory, and the stored program becomes a usable program after undergoing various debugging and test runs.

The creation of the above-mentioned programs has typically required a great deal of time and effort by skilled programmers. Although various high-level (close to human languages) programming languages have been developed and used to make programming easier, they still require coding work by programmers. Furthermore, the higher the eight words of the program, the larger and more complex the program for conversion into machine language, which makes it difficult to create and requires a large-capacity, high-speed memory to store it.

Therefore, a program creation method that does not require the effort of Coanda has been developed and researched in various fields. A typical example is graphic language. A graphic language aims to represent a processing process in a diagram, read it from an input device, and convert it into machine language using a pre-stored graphic translation program.

This eliminates the need for counders and makes programming easier.

Programmable controllers are often used for on/off control. That is, it controls the on/off timing of relays or switches in each part of the controlled system. Ladder-based graphics tiUJ is used to create such programs. This is a graphic language called a ladder diagram, which represents the status of relays that are controlled on and off in the form of a ladder. The rudder one-type is good for special purposes, but it is difficult for the general public to use and has little versatility. A flowchart type graphic language can be considered as a more versatile language than the ladder type. According to the conventional flowchart, this is too general-purpose and is not suitable for a programmable controller. In any case, it is necessary to code them using the middle eight words.

Recently, a method of inputting programs while creating them using a flowchart-based graphic language has been proposed. This involves inputting a program into a computer while creating a flowchart by fitting unit figures called graphic elements (or command symbols) and connecting them like a puzzle. It has a display that displays flowcharts and a keyboard that manually inputs command symbols. An example of this is shown in FIG.

In FIG. 1, 10 is a display screen.

Among these, the display area 12 (dotted line area) is called a view board, and a flowchart is displayed here.

As shown in the figure, the view boat 12 is divided vertically and horizontally into a grid pattern. Each area is now represented by a vertical and horizontal number (for example, area (1, 3)).

Reference numeral 13 is called a message area where information for the programmer is displayed.

Reference numeral 14 is called an assemble area, in which the currently input graphic element is displayed.

Four black triangle marks 1 shown on view boat 12
5 is a cursor. This can be moved up, down, left, or right in groups to specify an area.

Reference numeral 11 in FIG. 1 indicates a keyboard. Keyboard 11 has basic commands (CJ, TIM, CNT, 0LJT, JUMP
, SR, FROM) dedicated key, BiytJ! Dedicated keys for I-processing commands (AND, OR, DIF), keys for auxiliary commands (NOT, ~, R8T, *, etc.), group subroutine commands, data processing commands, keys for collectively specifying connection lines, and elements. ENT key, R'ET (return)
It is equipped with keys etc.

To create and input a flowchart, for example, proceed as follows (see FIG. 1).

First, the user presses the group menu key and selects the graphic element (GN) of the command representing the beginning of the program from the group menu and inputs it into area (0,0).

Next, a graphic element (CNT) representing a timer count reset process is input into the area (0, 1).

Below is the graphic element CJ that indicates jump (0
, 2) to the data transfer graphic element (MO
V) to (0,3) Graphic element (SU
Input B) into (1, 3). Area (1, 2), (0,
4) Input the graphic element of the connection line selected from the connection line menu in [1°4]. Each graphic element is first called to the assemble area 14, and then the element ENT key and cursor 15 are pressed.
is displayed and input in a predetermined area. FIG. 1 shows a subtraction instruction displayed in area (1, 3). That is, by pressing the data processing menu key, a list of data processing commands is displayed in the message area 13. By specifying number 14 from among these and pressing the RET key, the symbol of the 5UBL instruction is displayed in the 7th assembly area 14. Next, move the cursor to the area (1,
3) When the element ENT key is pressed, the screen shown in the figure is displayed and a subtraction command is input.

Note the *800 notation in this subtraction instruction. * represents the label of the instruction. It is a jump command (
CJ) jump destination is displayed.

Similarly, *800 must be displayed for the jump command in area (0,2). This indicates where to jump if the condition is not satisfied. As the flowchart becomes more complex,
The relationship between jump commands and their jump destinations requires special attention, and is also easily forgotten. Without this input, the compiler will not be able to complete the program. In a graphic language based on a flowchart, it would be convenient if there was a method that would allow a programmable controller to automatically correctly recognize the jump destination of a jump command without specifying the jump destination, but this has not been realized.

〔the purpose〕

The present invention has been made based on the above requirements, and an object of the present invention is to provide a method for determining a jump destination address of a jump instruction without specifying the jump destination.

(Structure) The method for determining the address of a jump specifying jump failure according to the present invention detects the first instruction of a group of instructions representing the processing condition of a jump instruction specifying skip failure in a programmable controller into which a program is input according to a flowchart. Next, the memory address where the detected instruction is stored is stored in a register, and a flag is set to indicate that the memory address of the instruction has already been stored in the register. Thereafter, instructions for subsequent processing conditions are executed. Finally, after the execution of the jump instruction is completed, the above flag is reset. If the processing condition is not satisfied, after executing the jump instruction, the program flow returns to the address stored in the above register, sets the flag again, and repeats the condition processing. If the conditions are satisfied, proceed to the next step by executing a jump instruction.

At that time, the flag is reset and the above registers are enabled.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an example of a flowchart of a jump designated as a jump failure.

In FIG. 2, instructions 30, 31, 32 represented by graphic elements (or symbols) represent processing conditions for a jump instruction 33. That is, instruction 30,3
The satisfaction state of the conditions constituted by 1.32 is instruction 33.
If the condition is satisfied, the flow proceeds to b; if the condition is not satisfied, the flow returns to a.

Instruction 30 sends operands 301, 302.3 to the CPU.
This is a command to detect that all relays (or switches) indicated by 03 are on.

OR instruction 32 sets operand 401゜4 to CPLI.
This is a command to detect that one or more of the relays (or switches) indicated by 02.403 are on.

AND instruction 31 has no operands. AN like this
The D instruction calculates the logical product of the execution results of the logical operation instructions before and after it.

In other words, the processing condition command group 30, 31, 32 in FIG.
It represents the AND with the logical sum of 402 and 403. In this way, in the flowchart type graphic 8, a processing condition command of unlimited length can be written before a jump command.

In addition to AND and OR, the instructions constituting the processing conditions include a differential processing designation instruction DIF. This is an instruction to detect the rising or falling edge of input bit data. ANDlo
The three instructions of RSD IF are called bit processing application instructions.

The bit processing application instructions form processing conditions for a jump instruction (CJ) singly or in combination.

The flowchart in FIG. 2 is decoded by a compiler and stored in the memory of the programmable controller as a sequence of machine language instructions. As is well known, such an instruction word is composed of an instruction code and an operand. The instruction code represents the type of instruction, and the operand represents the address to be executed by the instruction. Each instruction word corresponds to one address in memory.

The CPU reads the instruction word from the address indicated by the program counter and decodes the instruction code. Depending on the decoded result, the operation corresponding to each instruction code is executed.

For example, the execution of the AND instruction 30 in FIG. 2 is as follows. It is assumed that the AND instruction 30 is stored at memory address 1000 after being converted into machine language. Further, relays 301, 302, and 303 are connected to bit positions P1. of the input port of the programmable controller. P2.
When the relay is connected, the corresponding bit position indicates 1'', and when the relay is disconnected, it indicates 1''.
10 Let us indicate IT.

The CPLI reads the instruction word from memory address 1000 and decodes the instruction. Then, when it is identified that it is an AND instruction, the state of bit positions Pi, P2, and P3 (1
” or “0”) is transferred to one register (for example, the accumulator) of CPLJ. In the accumulator, the three bits are logically ANDed, and when all are “1”, the contents of the accumulator become 1’. OR A similar operation is performed when executing a command or a DIF command.

The three instructions AND, OR, and DIF are distinguished from other instructions as bit processing application instructions. That is, when converting these into machine language, a common identification bit is added to the instruction code so that when the instruction code is decoded, it can be identified that it is a bit processing application instruction.

Now, in the AND instruction 30 in FIG.
000) to an appropriate register. This is called the condition register. The CPU writes the memory address of the AND instruction into the condition register, and at the same time sets a flag 01° in the flag register to record the fact that it is self-instructed.

In the following instructions (31, 32), the CPU identifies that they are bit processing application instructions by decoding the instruction code, but since the flag register is checked and it is set, the memory address of those instructions is stored. do not. In other words, the contents of the RAD register for the condition are AN
The memory address (address 1000) of D instruction 30 is retained.

When the jump instruction (CJ) 33 is reached and the processing condition is not satisfied (branch No), the CPU transfers the contents of the RAD register to the program counter and transfers control of the program to address i ooo. This causes the program to start from location 10001.

The flag register is reset (to "0") by executing the jump instruction. The above loop process is repeated until the processing conditions are satisfied.

〔effect〕

The method for determining the address of a jump specifying a jump blunder according to the present invention makes it possible to use a jump instruction having an unlimited length processing condition without attaching a jump destination specifying label when creating a flowchart for a programmable controller. .

As a result, in programming the programmable controller, there is no need to pay attention to the connection between the jump command and the jump destination, and the burden on the programmer is significantly reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a method for creating and inputting a program using a flowchart type graphic language for a programmable controller, and FIG. 2 is a flowchart including a jump specifying jump. 30.31.32... Processing conditions, 33...
...Jump command. Applicant Nippon Electric Seiki Co., Ltd. Agent Patent Attorney Masu 1) Takeo

Claims (1)

[Scope of Claims] 1. In a programmable controller, detect the first instruction of a group of instructions representing the processing condition of a jump instruction with no destination specified, and store the memory address where this instruction is stored in a register and store it. 1. A method for determining an address for a jump with no destination specified, characterized in that a flag indicating completion is set, and the flag is reset after the operation of the jump instruction is completed. 2. The method for determining an address for an unspecified jump as claimed in claim 1, wherein the processing condition is one or a combination of instructions of logical sum, logical product, and differential processing.