CN1067166C - A Programmable Monitoring System Constructing a Ladder Diagram Using a Personal Computer - Google Patents

Abstract

The invention relates to a programmable monitoring system for constructing a ladder diagram by using a personal computer, which establishes a ladder diagram design function and a programmable controller execution function on the personal computer, and adds functions of timely archiving, printing and full-screen monitoring to form a super control data collection monitoring system. Various control cards are inserted into the personal computer and matched with various driving interface cards, so that the ladder diagram can be directly input, the control points and the logic output and input points are set, on one hand, the control signal output is executed, on the other hand, the set parameters are monitored by the full screen, the ladder diagram is directly input to the personal computer, and the editing, control and monitoring functions are integrated.

Description

A Programmable Monitoring System Constructing a Ladder Diagram Using a Personal Computer

The invention relates to a computer application technology, more precisely to a programmable monitoring system which uses a personal computer to complete the PLC function and edits and designs the function with a full-screen ladder diagram.

PLC programmable logic controller and personal computer have come out for more than ten years, and they have developed independently in the field of control. The general PLC programmable controller has specially developed a plasma screen for full-screen display, adopts a separate communication mode, and the edited program also needs to be input one by one with a writer (as disclosed in Taiwan Patent Publication No. 162359 technology), or with the help of a computer, but the PLC programmable controller itself does not have functions such as timely saving and printing, and must be connected to a personal computer to execute, and the personal computer needs to use C language, Basic or assembly language to complete these functions , so it is difficult for ordinary operators to complete this kind of work. As the survey results show, most of the staff who use PLC programmable controllers and need to monitor, file in time, and print do not know the above-mentioned languages. Designers of PLC programmable controllers must consider the improvement issues.

The purpose of this invention is to design a programmable monitoring system using a personal computer to build a ladder diagram, which is a monitoring system that directly inputs the ladder diagram with a personal computer, can directly perform near and far control and full-screen monitoring.

The system of the present invention moves the PLC function that is usually performed independently into the personal computer, and replaces the process of the personal computer using Basic, C, Pascal, and assembly language with the full-screen ladder diagram programming function, and inserts the general output and input control card, or remote Communication control module, adding timely saving, printing and full-screen monitoring functions that cannot be realized by PLC programmable controllers, has become a powerful monitoring system.

In this way, the computer is directly input in the form of a ladder diagram, and the user does not need to memorize the instructions one by one, and the computer can directly accept and execute them. In the past, the computer was only used as an editor, which could not be executed by itself and had to be transferred to another independent PLC programmable controller for execution. In particular, it can monitor whether the set parameters are correct on the full screen, receive the dual effects of direct control and monitoring, and can also be changed at any time.

The present invention uses personal computer to construct the programmable monitoring system of ladder diagram, comprises the keyboard input device that is connected with control, address, data bus, microprocessor, RAM-1, RAM-2 that store each executive module and calculation state result respectively Memory, read-only memory, printer driver interface connected with printer, floppy disk control card connected with floppy disk drive, communication sending and receiving data interface, display data temporary storage interface connected with full-screen monitor card and an output and input terminal, the system of the present invention is also provided with a control card connected to the output and input terminals and control, address, and data buses respectively, and has a locking temporary storage function for program control output and input. The control card can be equipped with or without a CPU. The system of the present invention has a photoelectric coupling array circuit connected to the output and input terminals. A photoelectric coupling circuit, the output end of the photoelectric coupling array circuit is connected to a coupling power circuit or a relay circuit.

The system of the present invention also includes a hardware setting module, a ladder diagram editing module, a ladder translation and PLC program monitoring module, and the computer control card has the function of flexible use and expansion of control points, and the control points and logic output are set in a custom input mode Corresponding to the input control point, and for irregular analog input and input control, it is executed by adding a drive interface card, and the ladder diagram is edited and constructed according to the general document through keyboard operation, and the computer input is realized. The control sequence is drawn and the parameters of each component are set, so that the computer can On the one hand, the input and output control can be performed directly, on the other hand, the correctness of the set hardware parameters can be monitored through the screen, so that the monitoring is integrated.

The function editor of the present invention can monitor the screen and display the position of the active point, and the program automatically reads the address of the active point and cooperates with the execution status of the PLC program for monitoring and display.

The electrical components with switching status of this system include proximity switches, pressure valves, etc., the analog electrical components with degree change status include thermometers, force gauges, etc., and the control equipment includes motors, frequency converters, etc. In addition to the human-machine interface functions of traditional PLC programmable controllers, this system also has control functions such as printing, full-screen environment, hard disk, various types of communication network interfaces, CD-ROM, voice, and storage.

The technology of the present invention will be further described below in conjunction with the embodiments and accompanying drawings.

Fig. 1 is a schematic block diagram of the system hardware structure of the present invention;

Fig. 2 is a block schematic diagram of the system software structure of the present invention;

Fig. 3 is the flow chart of hardware setting of the present invention;

Fig. 4 is a flow chart of ladder diagram program design of the present invention;

Fig. 5 is a flowchart of component editing in the present invention;

Fig. 6 is ladder translation and PLC monitoring flowchart of the present invention;

Fig. 7 is a ladder flow chart of the translation execution file of the present invention;

Fig. 8 is the PUSH-POP calculus control flowchart of the present invention;

Fig. 9 is a schematic diagram of the screen of the hardware setting module of the present invention;

Fig. 10 is a schematic diagram of file management of the programmable translation module of the present invention;

Fig. 11 is a schematic diagram of the interface card type and address setting selected by the programmable translation module of the present invention;

Fig. 12 is a stepwise control action program editing diagram of the present invention;

Fig. 13 is a schematic block diagram of a ladder control action program editing screen of the present invention;

Fig. 14 is the control monitoring and debugging screen displayed after the editing diagram of the ladder control action program of the present invention is archived.

Referring to Fig. 1, the system hardware structure of the present invention comprises a keyboard input device 1, a full-screen monitor 2, a soft and hard disk drive 3, a printer 4, an output terminal 5, an input terminal 5', a display data temporary storage interface card 6, a hard and soft disk drive Disc control card 7, communication sending and receiving data interface 8, printer driver interface 9, program control input and output control card 10 of latch type temporary register, microprocessor 11, store read-write memory 12 (RAM) of each execution module -1), read-write memory 13 (RAM-2) and read-only memory 14 (ROM) for storing calculation status results.

The stepwise execution program of the system may further include an editing module as shown in FIG. 5 , a translation module as shown in FIG. 7 , and an instruction group calculation control module as shown in FIG. 8 .

The program control input and output control card 10 of the latch-type temporary register in Fig. 1, its input terminal 5 ', connects the photoelectric coupling array circuit (OPTO), can be connected with the electric element that works in switch state such as proximity switch, pressure valve etc. , or connect with analog electrical components with degree change state such as thermometer, load cell (LOAD CELL), etc., and also connect photoelectric coupling circuit. The output terminal 5 is also connected to the power circuit and relay through the photoelectric coupling array circuit OPTO, or the device that controls the action with an analog signal, such as a servo motor, a frequency converter, etc.

The data of the programmable editing module and the translation module can be pre-stored in the soft and hard disk drive 3, and can also be pre-recorded in the ROM 14 for users to edit and construct ladder diagrams and translate ladder programs into PLC programmable controllers. instruction. The structure shown in Figure 1 can complete the functions of ladder program editing, translation, control output and input, full-screen monitoring, timely archiving and printing. In Fig. 1, 15 is address, data, and the bus bar of the control bus.

Referring to FIG. 2 , the functional modules of the system mainly include a hardware setting module 20 , a ladder diagram editing module 21 and a ladder translation and PLC program monitoring module 23 . Among them, the hardware setting module 20 is used to set the hardware environment and execute PLC or ladder editing, and after setting, it will generate the set parameter file for ladder translation and PLC monitoring; the ladder diagram editing module 22 can generate the set edit file, as the control program for ladder translation and PLC monitoring; the ladder translation and PLC program monitoring module 23 enters the PLC program with a setting file, and displays the monitoring point data 25 in execution on the full-screen monitor as shown in Figure 12 In the environment, the ladder diagram and its monitoring points 28, 26 can be printed out by the printer, and can also be archived in the soft and hard disk drive in time. The ladder translation and PLC program monitoring module 23 can also be used as a drive module for the system and different hardware interfaces. No matter what interface is added in the future or special communication with the remote control module, only this module needs to be modified or added. All kinds of PLCs can be connected to this system, and this system has strong compatibility and openness.

Referring to Fig. 3, it is the hardware setting module flow chart, among the figure 30 is program entry, and starts (31) by the parameter set by hardware, after the selected information display 32 and keyboard scanning, execution environment setting 33 Or ladder diagram editing 34 or PLC program control monitoring 35 or storage/clear display 38.

、常闭

或画线(一)，若为画线，则用“OR”逻辑演算其前后上下元件种类，自动布好游标位置的连线种类

，存档、取档、打印、删除、插入、拷贝或移动位置模块47具有方向及标示功能；结束程序48返回上层母程序。Referring to Fig. 4, it is a ladder diagram design flow chart, in which 40 is the program entry, after starting data structure and screen and function judgment 41, the operator can select a mode to carry out, including learning mode 42, normal design mode 43 and Showcase pattern 44. Wherein the learning mode 42 records the design process and saves it in another file, and the user can use the display mode 44 to display this learning process; the normal design mode 43 first displays the ladder program 45 on this page, and then scans the keyboard for selecting functions; the component editing module 45 including normally open

, normally closed

Or draw a line (1), if it is a line, use "OR" logic to calculate the types of its front, rear, upper and lower components, and automatically arrange the type of connection at the cursor position

, File, file, print, delete, insert, copy or move the position module 47 has direction and labeling function; End program 48 returns to the upper parent program.

Referring to Fig. 5, it is a flow chart of component editing. The program is input by scanning the keyboard 41, and the components are edited by the right key 461, the down key 462, and the up key 463, and the "OR" operation is used to connect or empty a space to reach the ladder. The editing purpose of the figure, and the identification of the variable is to use FLAG as the identification code, and set the editing structure Src[], CH[] 464 pointed by the cursor from the elements arrayed in the index element library Symbo[].

Referring to Fig. 6, it is the execution process of ladder translation and PLC monitoring, 50 is the program entry, after checking and configuring the memory area 51, to read the ladder program block to be executed, by translating and checking the ladder program syntax 52, to display the start screen 53, then judge 54 by function scanning and display screen, to enter the full-screen logical monitoring area 55, or self-defined screen monitoring area 56, or change screen 57, or store data and clear display 58.

Wherein the full-screen logic monitoring area 55 is to carry out the logical state (as shown in Figure 14) that each instruction group produces with derivation calculation mode, judge as the output condition, and represent the false/true of condition with 0/1, all each point state displayed on the screen. The self-defining picture monitoring area 56 is set by the user voluntarily, arranges and displays the active point position (as shown in Figure 14 ) voluntarily. The meaning represented by the active point is also input by the user according to the needs. This program first converts the value of the monitoring point with a self-defined formula and displays it at the position of the point. The changing picture 57 is used to switch the picture of the full-screen logical monitoring area 55 and the automatic picture monitoring area 56 . Execution completes the full-screen logic monitoring area 55 or self-defining screen monitoring area 56 or changing the screen 57 or storing data and clearing the display 58, then scanning the remote module control point status entered by the communication interface 59, updating the internal condition sign, as the next step Conditions for loop control.

，则视为逻辑件的代号LD，否则为“AND”形态，并将其运算元置于MC〔〕阵列内，再依其逻辑件位置换算为操作元种类522(如计时器、计数器、输出点、输入点、辅助接点、保持接点等)。当连线元件为“OR”型态时，即设定此逻辑件为ORB，并将该运算元置于MC[)阵列523内，当前连线元件为分岔元件，即设定此逻辑件为ANDB，并将该逻辑件为ORB，并将该运算元置于MC〔〕阵列524内。当为一输出运算元时，依其种类设定执行输出OUT、存挡(SAVEIN)、打印(PRINT)、上微分(DIFUP)或下微分(DIFDN)525，执行至最后一列526时，随即转换为MC〔〕阵列存贮器内进行控制程序，即图5中的显示选定监控画面53，继续进行前述操作。Referring to FIG. 7 , it is a flow chart of the step-by-step program for translation execution. The translation execution block 52 is divided into single and multi-line modes to form a command group to check whether the syntax is correct, and then cooperate with the judgment logic before and after the connection line type 521. If it is divided Fork components (such as

, it is regarded as the code LD of the logic part, otherwise it is in the form of "AND", and its operand is placed in the MC[] array, and then converted into the type of operand 522 according to the position of the logic part (such as timer, counter, output point, input point, auxiliary contact, maintaining contact, etc.). When the connection element is in the "OR" type, this logic element is set as ORB, and the operand is placed in the MC[) array 523, and the current connection element is a branch element, that is, this logic element is set It is ANDB, and the logic element is ORB, and the operand is placed in the MC[] array 524. When it is an output operand, it is set to execute output OUT, save (SAVEIN), print (PRINT), upper differential (DIFUP) or lower differential (DIFDN) 525 according to its type. When it is executed to the last column 526, it will be converted immediately Carry out the control program in the MC () array memory, namely the selected monitoring picture 53 of display among Fig. 5, continue to carry out aforementioned operation.

Referring to Fig. 8, Fig. 8 is a flow chart of programmable control of system PUSH-POP calculus, after selecting logic monitoring area 55 and self-defining screen monitoring area 56, enters calculus control, the steps are as follows;

One, read the flag 565 of the control card input temporary register setting memory RAM-2 (13 in Fig. 1);

Two, read the next group of MC () array instruction 566;

Three, judge the first operand kind, make the operand status flag be in the FG () storage unit 567;

4. Determine the type of the operand. If the flag of FG[] is 0, its flag is true/false, and the output action is performed;

5. The output action can enter four calculation states respectively;

(569) judge OR, ORB, ORI, AND, ANI, ANB, when it is one of them, do the FG [] flag operation, and do logic "AND" operation with the previous flag at the same time, and place the operation result in FG 〔〕Inside;

(570) When judging as LD, 1DI, this group of operands is promptly placed in FG [];

(571) when judging as outputting OUT, then judge kind by this group of operating elements, then flag is set in RAM-2 (13 in Fig. 1), output 0/1 to control card temporary register (in Fig. 1 10), and then sent to the output element (5 in Figure 1) connected to the output terminal.

(572) When it is judged as the upper differential (DIFUP), the "true" condition appears, and the rising edge outputs a pulse of a time cycle; if it is a lower differential (DIFDN), the "true" condition disappears, and the falling edge outputs a time cycle pulse pulse; if it is "print" (PRINT), then the "true" condition appears, and the specified data is sent to the printer; if it is "archive" (SAVEIN), the "true" condition occurs, and the specified data is sent to the software/ Inside the hard drive.

See Figure 9, which is a schematic diagram of the module screen for setting the hardware of this system. Its main action flow is still based on the aforementioned structure, and the steps are as follows:

1. The startup program can be started from the floppy/hard disk, and the execution command is read into RAM;

2. Set the address 67 of the control card;

3. The output/input working mode 66 of the function start control card type, and the control parameters of the function control card are stored in a floppy disk or hard disk with a file name 65;

Four, enter the ladder control program editor 60, its control program can be stored in the soft/hard disk 3 (Fig. 1) in advance, also can record in the ROM14 in advance (Fig. 1), the user edits according to the planning in advance.

5. Carry out ladder control design according to the ladder diagram program shown in Figure 4.

的标示为自动连线元件逻辑件

而其输出件表示如〔OUTR〕的输出点)。Six, element editing function 46 is finished by Fig. 5 flow process, and its ladder diagram program is stored in Src () structure variable memory 13 (RAM-2 of Fig. 1)

Autowiring Component Logic

And its output means the output point such as [OUTR]).

Seven, through the above steps, the completed ladder program is stored in the floppy disk 3 by the microprocessor 11 (Fig. 1).

8. The ladder program can be printed through the printer interface.

9. Enter the programmable translation module (61 in FIG. 9).

1. The data of the programmable translation module can be stored in the soft disk 3 (Fig. 1) in advance, and can also be recorded in the ROM 14;

连线符号；分岔方块，即由分岔元件组成的阶梯图，如函12中的03列、004列，并由800、207、206组成一方块(BLOCK)。2. The program translates the user's ladder program into instructions; its detailed execution steps are shown in Figure 7, and the operation elements include timers, counters, output points, input auxiliary contacts, and hold contacts; Input LDI, and AND, and non-ANDI, or OR, or non-ORI, block and ANB, block or ORB, upper differential DIFUP, lower differential DIFDN, output OUT, archive SAVEIN, print PRINT; branch components such as

Connection symbol; bifurcating square, that is, a ladder diagram composed of bifurcating elements, such as column 03 and column 004 in letter 12, and a block (BLOCK) composed of 800, 207, and 206.

Ten, the ladder diagram program of Fig. 12 is transferred into MC () array variable storage body internal storage by Src () structure variable memory, its step is:

1. The programmable control module is stored in the MC[] array variable memory 13, and is executed cyclically through the steps of reading, judging, setting, outputting, and displaying;

2. The program enters the ladder translation and PLC monitoring as shown in Figure 6. After keyboard scanning 54, select full-screen logic monitoring 55 or custom screen monitoring 56 or change screen 57 or save data and clear display 58 to monitor the communication position Data or the connection data 59 of the remote control station, the user can execute the programmable control program;

3. Through the full-screen logic monitoring 55 and the self-defined screen monitoring 56 (Fig. 6), the derivation calculation method is used as the main execution program of the programmable control (Fig. 8), and the cyclic actions are read, judged, set, and output. That is, read the flag of the memory 13, then read the next group of MC [] array instructions, and judge the first operand type, and store the flag representing the present situation of the operand in the PUSH-FG [ of the memory 13 ] In the storage unit, when judging the operand, if the index of PUSH-FG [] is 0, its flag is true/false, and the output is executed.

After the ladder program design shown in Figure 12 is archived, enter the Run mode environment, and the operation screen shown in Figure 13 and Figure 14 will appear, in which;

1. Display the instruction group after ladder translation (read from 13 in Fig. 1), and display it cyclically on window 80 (as shown in STEP TRACE in Fig. 14), and the user can test the program and execution results step by step in a tracking mode;

2. Guide users to use command mode 88;

3. The status display area of the input and output virtual contacts in this control system can be divided into non-memory virtual contacts, commonly known as internal general auxiliary contacts 89 (AUX in Figure 12), and memory virtual contacts, commonly known as internal holding auxiliary contacts. The original logic state can still be maintained after power off.

Actual input point state display area 81, each input state is 1 byte, equal to 8Bits is 8 points of input, so numbering 0-7, 10-17, 20-27...its actual relative position is by 67I/O-CH1 of Fig. 9 . Internal settings (same position as in Figure 10 and Figure 11). And when the interface card is selected, the address is automatically set, unless there is more than one interface card, or its position is special, it needs to be adjusted by the user. By monitoring this area 81, the user can know the input status of the actual contact point of the external wiring. A hypothetical time relay contact area 82 is the timer area, as shown in Figure 14, 80 in the table is from 800 to 807, 81 is 810 to 817, 810 is 0#7, 0 on the left side of # indicates the timer It can be turned off (OFF) when it is in the 0 state, and 7 means that there are 0.7 seconds left in the timing. When the timing is 0, the left O turns to 1 (ON), so the timers in this system are all ON DELAY. The counting unit is 0.1 second. The counting area 83 records how many counting operations there are, such as the counting control of the production quantity. As shown in the counting area 83 in Figure 13, the position of 90 in Figure 14, 90 represents addresses 900 to 907, and 91 represents 910-917, which are available counters, such as "0#21" at 900, indicating the current channel There are 21 counts accumulatively, the state is still 0 (OFF), and the final counting value set by the program has not yet been reached (users need to pre-set the control of each counter). Actual contact output state display area 84 (1=ON, 0=OFF in Figure 14), the user can monitor the actual state of the actual machine control point action on this screen, in this output area 84, 200 represents 200 to 207, 210 Indicates 210-217... According to the actual location of the interface card, another flexible use space is provided to the user. The user-defined display screen has 85 active points to display the position marking area. The user can use Ctrl-U to enter a specific screen as needed, and the current situation of the control point is reflected in the customized screen in time, which is convenient for the user to issue commands quickly. The display area 86 is used to display the environment information related to the current program execution, so as to avoid the situation that wrong parameters are given but not known. The current status of the display system running is displayed in the 87 area, so that the user can know whether there is any error in the running of the system.

The display function of the above screen is automatically executed after the translation of the ladder program. It has the function of ladder design on a personal computer and PLC programmable controller. It can provide monitoring and timely display, archiving, and printing of results without language design. , the human-machine interface of the controller itself, etc.

The invention not only can be used for learning, but also can be used as a tool for realizing automation in the industry.

Claims (10)

1. A programmable monitoring system using a personal computer to build a ladder diagram, including a keyboard input device connected to a control, address, and data bus, a microprocessor, and RAM-1 and RAM for storing each execution module and calculation status results respectively. -2 memory, read-only memory, printer driver interface connected with printer, floppy and hard disk control card connected with floppy and hard disk drive, communication sending and receiving data interface, display data temporarily connected with full-screen monitor Storage interface card and an output and input terminal, it is characterized in that: also comprise a control card with or without CPU, have locking temporary storage function, be used for program control output and input, respectively with output and input terminal and control, address, data bus connect; It also includes a photoelectric coupling array circuit connected to the output and input terminals, the input terminal of the photoelectric coupling array circuit is connected to an electrical component operating in a switch state or an analog electrical component operating in a degree change state or another photoelectric coupling circuit, and the output terminal of the photoelectric coupling array circuit is Connecting coupled power circuits or relay circuits; The described floppy disk drive or read-only memory stores a hardware setting module for setting the hardware environment and providing a PLC or ladder editing window to generate the set parameter file for ladder translation and PLC Program monitoring and execution; store a ladder diagram editing module, which can generate the set edit file and ladder translation, PLC program monitoring control program; store ladder translation and PLC program monitoring module, enter the PLC program execution with the set file , display control point data in a full-screen monitoring environment. 2, a kind of application personal computer as claimed in claim 1 builds the programmable monitoring system of ladder diagram, it is characterized in that adopting following operation steps: a) Start the program by the soft disk, and read the execution command into the read-write memory RAM-1 of each execution module; b) Set the program control I/O address of the control card; c) Set the program to control the I/O working mode of the I/O control card type, and store the control parameters in the hard disk or floppy disk with a file name; d) The function enters the editing of the ladder control action program, and edits according to the ladder control action program stored in the floppy disk or the read-only memory ROM; e) Ladder control design according to the functional flow of the ladder diagram program design; f) According to the component editing process, use automatic connection components, logic components, and output components to make a ladder diagram, and store the completed ladder diagram in the Src [] structure variable memory of the read-write memory RAM-2 of the calculation status result middle; g) The microprocessor sends the designed ladder diagram to the soft and hard disk drive for storage; h) The ladder diagram is printed and archived by the printer through the printer interface. 3. The programmable monitoring system for constructing a ladder diagram using a personal computer according to claim 1, characterized in that: the control card used for program control output and input is a communication interface for remote control points, and the The remote control point has a microprocessor, an independent control program and a simple I/O port. 4. The programmable monitoring system for constructing a ladder diagram using a personal computer according to claim 2, characterized in that: in the step f, according to the keyed up, down, and right keys, the up, down, and right keys of the position are calculated with "OR". , down, left, right, upper right, lower right, upper left, lower left component type value, according to the operation result, index the component from the component library stored in the read-write memory RAM-2 of the calculation status result, and then set it to the current one For the edited components, edit the ladder diagram one by one. 5. According to claim 2, the programmable monitoring system using a personal computer to build a ladder diagram is characterized in that: in the step d, the condition values of each control point are first pushed one by one and temporarily stored in the readout of the calculation status result. Write in the flags in memory RAM-2, and when the ladder execution operation is output type, use the last-in-first-out method to take out the flag values in the read-write memory RAM-2 of the calculation status results, and "AND" one by one Logical operations, output results according to the type of operands, and complete one cycle of calculation one by one. 6. The programmable monitoring system for constructing a ladder diagram using a personal computer according to claim 1, characterized in that: said ladder translation module translates operands, operation elements, branching elements, and branching blocks into instructions. 7. The programmable monitoring system using a personal computer to build a ladder diagram according to claim 2, characterized in that: said ladder diagram is composed of the Src [] structure variable in the read-write memory RAM-2 of the calculation state result The memory is transferred into the MC[] array variable memory for the cyclic calculation of reading, judging, setting, outputting and displaying. 8. The programmable monitoring system using a personal computer to build a ladder diagram according to claim 7, wherein the operation steps of reading, judging, setting, outputting, and displaying are; a) Keyboard scanning input, select full-screen logic monitoring or custom screen monitoring or change screen or store data or clear display, monitor communication address data or connection data of remote control station, and provide programmable control to users; b), according to the full-screen logic monitoring and self-defining screen monitoring, take the calculation method, read the setting flag and read the next group of MC[] array instructions from the read-write memory RAM-2 of the calculation status result, and judge the first One type of operation element, store the operation element current status flag in the PUSH-FG [] memory of the read-write memory RAM-2 of the calculation state result, PUSH-FG [] is 0, and the flag is true/ False, execute output. 9. The programmable monitoring system for constructing a ladder diagram using a personal computer according to claim 1, characterized in that: said ladder translation and PLC monitoring execution is to first check and configure the memory area to read the ladder to be executed Program files; then translate and check the syntax of the ladder program to display the start screen; then judge by function scanning and display screen to enter the full-screen logic monitoring area or custom screen monitoring area, or change the screen, or save data or clear the display ; The full-screen logic monitoring is to execute the logic state generated by each command group in a derivation calculation mode, as the judgment of the output condition, and represent the false/true of the condition with 0/1, and display the status of all points on the screen; The monitoring area of the self-defined screen is the active point position set and displayed by the user himself, and the meaning of the live point is input by the user, and the program converts the value of the monitoring point with a custom formula and displays it on the position of the point ; Described changing picture is that the picture of full-screen logical monitoring area and automatic picture monitoring area is switched mutually; The said storing data and clearing the display is to scan the status of the remote module control point entered through the communication interface after execution, update the internal condition flag, and prepare to enter the next cycle of control. 10. The programmable monitoring system using a personal computer to build a ladder diagram according to claim 2, characterized in that: said component editing is input by scanning the keyboard, and the editing is carried out by the right key, the down key, and the up key Components and "OR" operations are connected or empty to complete the editing of the ladder diagram, and the setting of variables uses FLAG as the identification code, and the components in the Symbol array of the index component library are set to the editor indicated by the flag In the structure SrC[], ch[].

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