Summary

This manual has a comprehensive introduction to the basic functions of WECON PLC Editor and the actual use. This book is completely aimed at zero-based readers, which is an essential reference book for entry-level readers to quickly and fully grasp WECON PLC and WECON PLC Editor. 

This book starts from the basic product of WECON PLC and the basic concept and operation of WECON PLC Editor. It combines with a large number of cases and graphic analysis to comprehensively and deeply explain the use of WECON PLC Editor Software, as well as PLC program.

WECON technology Co., Ltd. All rights reserved.

Precautions

Before the installation, operation, maintenance and repair of the micro programmable control, please read this manual and other related manuals to ensure correct use. Please use it after you have mastered the operation method, safety information and all

Design

In the event of an abnormality in the external power supply or failure of the programmable controller, to ensure the safe operation of the entire system, be sure to install a safety circuit outside the programmable controller.

1. Be sure to install an emergency brake circuit, a protection circuit, an interlock circuit for reverse operation, such as an emergency brake circuit, a protection circuit, a forward and reverse circuit, and an interlock circuit for the upper and lower positioning limits to prevent machine damage, in the external circuit of the programmable controller.
2. When the programmable controller CPU detects abnormal conditions such as WDT errors through self-diagnosis, all outputs are shut off. In addition, when the programmable controller CPU cannot detect abnormalities in the input/output control part, etc., it cannot control the output. At this time, in order to make the machine operate safely, please design the external circuit and mechanism.
3. Due to the failure of the relay and transistor of the output unit, it is impossible to control the state of the output to ON or OFF. In order to ensure the safe operation of the machine, please design external circuits and mechanisms for output signals related to major accidents.

Installation

• Please use it in the general specification environment described in the manual.
  • Do not use in the following places: places with dust, oily smoke, conductive dust, corrosive gas, flammable gas; places  exposed to high temperature, condensation, wind and rain; places with vibration or impact. Electric shock, fire, and misoperation can also cause product damage.
• When processing screw holes and wiring, do not let iron filings or wire ends fall into the ventilation window of the programmable controller. It may cause fire, malfunction, or misoperation.
• Please insert the connecting cable and display module accurately into the specified sockets. Poor contact may cause misoperation.

Wiring

The signal input and output lines of the programmable controller cannot pass through the same cable.

In addition, signal input lines and output lines cannot pass through the same pipeline with other power lines and output lines, and cannot be bundled together.

If implemented according to the above precautions, even if the input and output wiring is as long as 50 to 100m, there is almost no noise problem. But generally for safety, the wiring length should be within 20m.

• Please connect the AC power supply to the dedicated terminal according to the content in the manual.
• If the AC power supply is connected to the DC input/output terminal or the DC power supply terminal, the programmable controller will be burnt out.
• Please do not supply power to the 24+ terminal of the basic unit from the external power supply, and to the empty terminal    . Do not wire from the outside, otherwise the product will be damaged.
• Please ground the ground terminal of the basic unit according to the third method. But please do not share the ground with the strong current system.

Attached

The programmable controller will continue to work if there is an instantaneous power failure of less than 10ms.

When the power is cut for a long time or the voltage is low, the programmable controller will stop working and the output will turn OFF, but once the power supply is restored, it will automatically restart.

Startup and maintenance

Maintenance

Regular inspection: Whether the programmable controller is equipped with consumables with a shorter life.

For relay output type, if the output relay works abnormally at a high frequency or drives a large-capacity load, you must pay attention to its impact on the service life.

Check with other equipment, please pay attention to the following points:

• Whether there is an abnormal increase in the temperature inside the machine due to other heating elements or direct sunlight.
• Whether dust or conductive dust has penetrated into the machine.
• Whether there are loose wiring and terminals or other abnormalities

Scan structure

The scan configuration of the CPU module is as follows.

Initialization

The initialization based on the status of the CPU module is as follows.

• √: execute
• ×: not execute

Input and output point refresh

Perform the following before starting program calculation.       

• Update the actual input point of the PLC to the input relay X.

The following is executed after the END instruction is executed.

• Update the PLC output relay Y to the actual output point.

Key points

When performing a constant scan, the I/O refresh is performed after the waiting time of the constant scan.

Operation of the program

According to the program setting, the execution starts from step 0 of each program to the END instruction. This program is called the main program.

END processing

Perform the following processing.

• Completion processing of partial instructions
• Watchdog timer reset
• Communication processing
• Setting the value of special relay/special register (when the setting timing is END processing)

Scan time

The CPU module repeats the following processing, and the scan time is the total of the following processing and execution time.

The initial scan time indicates the time including this processing.       

Initial scan time

It is the first scan time of the CPU module in RUN.

Process as the following way: The value stored in SD134 (initial scan time (ms unit)) and SD135 (initial scan time (s unit)).

The flow of each procedure

When the CPU module changes to the RUN state, the programs are executed in sequence according to the program execution type and execution sequence settings.

Key points

When the execution types of the programs are the same, they are executed in the order set in the execution order.

Types of program execution

Scan execution program

Each scan is executed only once from the next scan of the initial execution type program.

When multiple scan execution type programs are executed, the execution time of the scan execution type program is the time until all scan execution type programs are executed. In addition, before the execution of the scan execution type program is completed, if an interrupt program/event execution type program/subroutine is executed, the execution time will also be included.

Creation of multiple scanners

"Project Management"→ "Program"→ "Scan"→ Right click to create

1. Scan the program name: the program name requires to match case, and the program name cannot use the same name with device name (the device name does not match case).
2. The input of /%$@&=~`^<>?:{}[],;!*.\\'" is not supported. It cannot exceed 64 characters. The default name is MAINx.
3. The number of scan programs that can be built is limited to 100.
4. Each scan program has been END ended, but only the last END instruction is completed to calculate a scan cycle.
5. The execution sequence runs from top to bottom in the order of creation.

Event execution program

It uses the event specified by the user as a condition to trigger the program to start execution.

Trigger type

The trigger of event execution type program is as follows.

ON event of bit data (TRUE)

• After the ON event is specified, if the contact that sets the trigger condition in the ON event is turned ON during the scan program, the ON event program will be executed in the scan program page*1 or before the END instruction is executed.
• The ON event program will only be executed once in a single scan cycle.
• After the ON event is executed, you can set whether to clear the current value of the output (Y) and timer (T) used in the program.

*1: Scan program paging: multiple scan programs are established, and each scan program is called a paging. After scan program A is executed, before scan program B is executed, it will be judged whether an event program needs to be executed.

When it is the turn of the execution sequence of event execution type program C and Y50 is ON, the program is executed.

The devices that can be specified are as follows.

*1 The indexed device cannot be specified.

TIME event

After the program is to RUN state and the specified time has elapsed, event is executed one time when it comes to the execution sequence of the first corresponding program. For the second and subsequent executions, the time is re-measured from the start of the last event execution type program. After the specified time has elapsed, the program is executed repeatedly when it comes to the execution sequence of the first corresponding program. In addition, in the next scan after the corresponding program is executed, the current value of the output (Y) and timer (T) used in the corresponding program can be cleared. It can be used for programs that do not need to respond in a fixed period of time.

After the specified time has elapsed, when it comes to the first execution sequence, the event execution type program C is executed.

Key points

When set to clear the current value of output and timer, and the scan time is longer than the set value of elapsed time, the current value of output and timer will not be cleared.

Operational steps

1）New event

Project management→ Program→ Event → Right click to create.

Event program name:

• The program name requires to match case, and the program name with the same name as the device cannot be used (the device name does not match case).
• The program name does not support /%$@&=~`^<>?:{}[],;!*.\\'" character input.
• The length of the program name cannot exceed 64 characters. The default name is EVENTx.

A maximum of 100 new event programs could be created.

2) Execution type

There are two ways to configure the event execution type:

1. Configure when creating a new event program, as shown in the figure above.w
2. Project management→ Program→ Parameter → Program parameter→Configuration

Configuration instructions:

 Configuration interface

Parameter content:

Key points

When "ON event" or "TIME event" is specified, if "Clear or not" is set to "Clear", the event program will not be executed in one scan cycle, and all the internal outputs (Y) and current value of timer (T) will all be cleared (except for the cumulative type and subroutine type T). If the time set by the TIME event is less than the scan period, it is equivalent to executing the TIME event every scan period. Even if the clear output is set, the output and timer data in the event program will not be cleared.

Interrupt execution program

In the process of executing the scan program, the program that can interrupt the priority execution of the scan program is called an interrupt execution program.

• When an interrupt cause occurs, the interrupt program corresponding to the interrupt pointer number will be executed. However, the execution needs to be set to the interrupt enabled state by the EI instruction.

• An interrupt name corresponds to an interrupt program, and the interrupt name cannot be repeated. Each interrupt has its own trigger condition and execution program, and each interrupt program ends with END.
• Interrupt has the characteristic of interrupting the original execution program and executing the interrupt first, but it cannot interrupt the interrupt program being executed.
•  The interrupt program has the concept of priority. The smaller the priority value, the more priority the response. The priority setting range is 0 to 2.

The actions when an interruption cause occurs are as follows:

• Interrupt prohibition (DI) when an interruption cause occurs.
  • If the interrupt execution condition is triggered in a program that is forbidden by DI, the interrupt will not be executed. Even if the subsequent program uses the EI instruction to allow interruption, the previously shielded interrupt program will not be executed. Only the interrupt execution condition is triggered again. The interrupt program will be executed.
•  When multiple interrupt causes occur simultaneously in the interrupt enabled state.
  • The interrupt program with higher priority will be executed sequentially. In addition, when multiple interrupts with the same priority occur at the same time, the actions are executed in the order of interrupt priority.
  • If three interrupt programs I0, I10, I16 are created, the priority of I0 is 1, the priority of I10 is 0, and the priority of I16 is 1. The execution logic is shown in the figure below: I10 has the smallest priority and is executed first; I0 and I16 have the same priority and are executed in the order of program establishment.

• When an interrupt occurs during the waiting time when performing constant scan.
  • Execute the interrupt program for this interrupt.
• When other interrupts occur during the execution of the interrupt program.
  • In the interrupt program (including the specification when the interrupt occurs in the event execution program), when other interrupts occur, the original interrupt execution program will not be interrupted. After the original interrupt execution program is completed, the new interrupt program is executed. After the execution is completed Then return to the scanning procedure.
• During the execution of the interrupt program, when an interrupt cause with a low priority or the same priority occurs.
  • The interruption cause that occurred is stored, and after the interrupt program in execution ends, the interrupt program corresponding to the stored interruption cause is executed. Even if the same interruption cause occurs multiple times, the interruption cause is stored only once.

• When the same interruption cause occurs during the execution of the interrupt program;
  • The interruption cause that occurred is stored, and after the interrupt program in execution ends, the interrupt program corresponding to the stored interruption cause is executed. Even if the same interruption cause occurs multiple times, the interruption cause is stored only once.

Interrupt trigger condition classification

• External input (X) interrupt
  • Description of external input interrupt
    • The external input interrupt is triggered by the rising or falling edge of the fixed X point input.
    • Supports the rising and falling edge interrupts of a total of 8 input points of X0 to X7, and supports a total of 16 external input interrupts.
    • The same interrupt trigger condition cannot create multiple interrupt programs.
    • External input interrupt and high-speed counter cannot use the same X point.
    • You must use EI in the scan program to allow interrupts before the interrupt execution program will be executed.
• External input interrupt steps.
  • Project management→ Program→ Interrupt→ right click to create.
  • The interrupt program name requires to match case, and the program name with the same name as the device cannot be used (the device name does not match case),
  • The interrupt program name does not support the input of /%$@&=~`^<>?:{}[],;!*.\\'" characters,
  • The length of the interrupt program name cannot exceed 64 characters and cannot be typed. The default name is INTx.

• Click Configure, and select external interrupt for execution type, as shown in the figure below (it can also be configured in "program parameters" in "parameters" in project management):

• Write interrupt execution program

Double-click the newly created interrupt program in the project management to start writing the interrupt execution program. As shown in the figure above, a newly created interrupt program is INT_X0_UP, and the trigger condition is configured to execute the interrupt program when the X0 rising edge is configured. If the EI instruction is used in the main program to allow interrupts, all programs in INT_X0_UP will be executed whenever X0 changes from OFF to ON , That is, D0 will increment once.

Timer interrupt

Timer interrupt description

• Timer interrupt is based on the set time, execute the interrupt program every this time, the minimum time interval can reach 100us.
• Up to 100 timer interrupt execution programs can be created.
• Each timer interrupt program is independent of each other and does not affect each other.
• Each timer interrupt program should be configured with priority. When triggered at the same time, it is executed in the order of priority, but when the priority is the same, it is executed in the order of the established program.
• The interrupt execution program is executed only after EI is used in the scanner to allow the interrupt

Timer interrupt step

• Project managementðProgramðInterruptðRight click to create. Enter the program name. The program name only supports the combination of English letters, numbers, and underscores, and must start with an English letter. The default is INTx. Click Configure and select Timer Interrupt as the execution type, as shown in the figure below (it can also be configured in "program parameters" in "parameters" in project management).

Write interrupt execution program

• Double-click the newly created timer interrupt program in the project management to start writing the interrupt execution program. As shown in the figure above, a newly created timer interrupt program is INT0, and the trigger condition is configured to execute the interrupt program every 10ms. If the main program uses EI to enable interrupts, all instruction programs in INT0 will be executed every 10ms, namely D0 It will add 1 to 10ms.

High-speed counter interrupt

Description of high-speed counter interrupt

• The high-speed counter interrupt triggers an interrupt condition after the set value of the high-speed counter HSC0 to HSC7 provided by the PLC and executes the interrupt program.
• It can support up to 100 high-speed counter interrupt programs, but the number that can be supported by each channel does not need to be fixed.
• When using the high-speed counter interrupt, project must configure the high-speed counter and use the OUT HSC instruction to enable the corresponding counting channel to count before it can be used (see the high-speed counter description section for the specific configuration method).
• Each high-speed counter interrupt program should be configured with priority. When triggered at the same time, it will be executed in the order of priority. When the priority is the same, it will be executed in the order of channels HSC0-HSC7. When the channel is also the same, it is executed in order according to the creation promise.
• Project must use EI in the scan program to allow interrupts before the interrupt execution program will be executed.

High-speed counter interrupt steps

• “Project management”ð“Programð“Interrupt”ðRight click to create. Enter the program name. The program name only supports the combination of English letters, numbers, and underscores, and must start with an English letter. The default is INTx. Click Configure, select high-speed interrupt for execution type, as shown in the figure below (it can also be configured in "program parameters" in "parameters" in project management).

 Description of triggering rules

Write interrupt execution program

• New interrupt program
  • Create three new interrupt programs under the interrupt of project management, namely HSC0_20000, HSC0_30000, HSC0_40000. Configure the interrupt program in the "program parameters", as shown in the figure below.

• High-speed counter configuration
  • Configure HSC0 for use in the high-speed counter configuration. After selecting the working mode, click the "Check” button. After the correct configuration box pops up, click Enter.

Call the high-speed counter in the main program and enable interrupts:

Program operation:

• Assuming that the High-speed counter channel 0 has been receiving pulses:
  • When the count value of HSC0 accumulates from 0 to 20000, all procedures of HSC0_20000 are executed.
  • When the count value of HSC0 is accumulated from 20000 to 30000, all procedures of HSC0_30000 are executed.
  • When the count value of HSC0 is accumulated from 30000 to 40000, all procedures of HSC0_40000 are executed.

Mask interrupt

Mask through application instructions

• The PLC interrupt is in the shielded state by default when it is powered on, and can only be used after the interrupt is allowed through the EI instruction.
• The interrupt mask instruction DI masks all interrupts without parameters, and masks some priority interrupts with parameters (refer to the program flow instruction DI/EI for details).

Mask through special registers SM and SD

1. high-speed counter interrupt mask register

Subroutine

During the execution of the scan program, the executed program can be called by the CALL instruction. You can create up to 100 new subprograms.

A subroutine is to split a certain module in the main program for the main program to call, which is conducive to the modularization of the program. Such as other high-level language functions, but this function has no parameters and no return value.

Instructions for calling subroutines

After a new subroutine is created, the content of the program is not executed. It is executed only when the CALL(P) instruction is used to call the subroutine in the scan, event, and interrupt programs, and the call is executed once. Three new subroutines SUB0, SUB1, SUB2 are created as shown in the figure below. In the main program MAIN, the subprogram can be called by using the CALL(P) subprogram program name.

Through this programming method, the use of the same logic program for different conditions can reduce the number of Circuit program steps and improve the readability of the Circuit program.

Positioning instructions

Event

ON event

• If the high-speed pulse instruction is turned on during the ON event, the high-speed pulse instruction will be sent as normal. If the ON contact of the trigger event in the scan period is turned OFF during the pulse sending, select whether to continue sending the pulse or stop the pulse according to the unscanned processing flag bit.

• When the flag bit is 0 (continue to send pulse), if the instruction is not scanned in the current scan cycle, continue to send pulses until it stops. At this time, it should be noted that if the trigger event OFF contact turns ON after the pulse is sent, the pulse will be sent again.
• When the flag bit is 1 (stop sending pulses), if the trigger event ON contact turns OFF in a certain scan period, it will decelerate and stop.

 TIME event

• If the high-speed pulse instruction is turned on in the TIME event, the high-speed pulse instruction will be sent as normal. If the instruction is not scanned in a certain scan period during the pulse transmission, select whether to continue sending the pulse or stop the pulse according to the unscanned processing flag bit.

• When the flag bit is 0 (continue to send pulse), if the instruction is not scanned in the current scan cycle, the pulse will continue to be sent until it stops. In the TIME event, it is impossible to ensure that the instruction is scanned in every scan cycle, so you should avoid using high-speed pulse instructions in the TIME time, otherwise the pulse will be sent again after the pulse is sent.
• When the flag bit is 1 (stop sending pulses), if the instruction is not scanned in the current scan cycle, it will decelerate and stop. In the TIME event, if the flag bit is set to 1 (stop sending pulses), there will be no pulse sending.

Subroutine

If the high-speed pulse instruction is turned on in the subroutine, the high-speed pulse instruction will be sent as normal. If the scanning period is closed during pulse sending, select whether to continue sending or stop the pulse according to the unscanned processing flag.

When the flag bit is 0 (continue to send pulse), if the instruction is not scanned in the current scan cycle, the pulse will continue to be sent until it stops. At this time, it should be noted that if the subroutine is called again after the pulse is sent, the pulse will be sent again.

When the flag bit is 1 (stop sending pulses), if the subroutine is closed during high-speed pulse sending, the speed will decelerate and stop. If the subroutine is closed before sending the pulse, then no pulse is sent.

Interrupt

External interrupt

• If the high-speed pulse instruction is enabled in the external interrupt, the high-speed pulse instruction selects whether the pulse continues to be sent or the pulse stops according to the unscanned processing flag bit.

• When the flag bit is 0 (continue to send pulse), continue to send high-speed pulses until it stops.
• When the flag bit is 1 (stop sending pulse), the high-speed pulse decelerates and stops.

Timer interrupt

• If the high-speed pulse instruction is turned on in the timer interruption, the high-speed pulse instruction is sent as normal. If the instruction is not scanned in a certain scan period in the pulse transmission, the pulse continues to be sent or the pulse stops is selected according to the unscanned processing flag.

• When the flag bit is 0 (continue to send pulse), if the instruction is not scanned in the current scan cycle, continue to send pulses until it stops. In the timer interrupt, it is impossible to ensure that the instruction is scanned in every scan cycle, so it is necessary to avoid using high-speed pulse instructions in the T timer interrupt. Otherwise, after the pulse transmission is completed, the pulse will be sent again.
• When the flag bit is 1 (stop sending pulses), if the instruction is not scanned in the current scan cycle, it will decelerate and stop. In the TIME event, if the flag bit is set to 1 (stop sending pulses), there will be no pulse sending.

High-speed comparison interrupt

• If the high-speed pulse instruction is enabled in the high-speed comparison interrupt, the high-speed pulse instruction selects whether the pulse continues to be sent or the pulse stops according to the unscanned processing flag.

• When the flag bit is 0 (continue to send pulse), continue to send high-speed pulses until it stops.
• When the flag bit is 1 (stop sending pulse), the high-speed pulse decelerates and stops.