PLC currently occupies a heavier position in industrial automation. The continuous development of technology has greatly promoted the improvement of control functions and control levels in the control system based on PLC.
At the same time, its control methods, operating levels, and intuitive personalized operating performance requirements are also increasing. Therefore, the interactive operation interface, alarm records and printing requirements also become important content of the entire control system. For an industrial control system with a complex process and a large number of control parameters, it is particularly important. Therefore, the appearance of the industrial HMI and HMI provides a convenient and feasible human-machine dialogue path for the realization of the above functions in the construction of the PLC control system, providing a better choice for the transformation of the grinder industrial control system.
The features and functions of the industrial man-machine interface, also known as touch screen monitors, are an operation control display device. Its hardware consists of a power supply, a touch resistor network, a display, memory, and an IYO expansion interface. The HMI is based on a specially designed computer system (32-bit RISC CPU chip). A transparent resistive network touch screen is mounted on the STN, TFr liquid crystal display, or EL (Electro Luminescence) display. When the screen is touched, the resistance and voltage on the resistor network change and the touch position is calculated by the software.
The main functions are: input and display of data, real-time information display of the operating status of the system or equipment, setting the touch control on the HMI can be used as the operation panel to control the operation, alarm processing and printing; in addition, the new generation of HMI also has a simple Programming, input data processing, data logging and recipes, and other intelligent control functions.
Application on PLC Industrial Control System
1, system overview
The automatic cycle of the grinding machine includes loading, magnetic, quick jump, fast trend, black skin grinding, coarse movement, fine movement, and light grinding.
The original configuration of the control system for the UCN281 small industrial computer, due to its poor stability, high failure rate, often cause equipment downtime. During the retrofitting process, the system hardware was changed to consist of PLCs and detection instruments. The field device control devices consisted of stepper motors, harmonic reducers, ball screws, and the like. Under normal circumstances, according to the requirements of the production process, coordinate the work of each grinding process control system, set grinding parameters, and achieve full automation of the entire grinding cycle. The core control part of the whole system is implemented by OMRON, and the system's monitoring and interactive operation interface tasks will bear the HMI. The main contents are as follows: Parameter setting, dynamic screen display, parameter display of grinding process, fault alarm and diagnosis. Among them HMI chooses step-by-step e-VIEW-506L.
2. Communication between HMI and PLC
When the HMI is used in a PLC control system, the HMI communicates with the PLC via a serial port in a D-LINK (direct connection) mode. In this mode, the HM I reads the PLC data directly or writes the data to the corresponding PLC address. Because of the built-in communication protocol, there is no need to compile the communication program. Just specify the type (ie, communication protocol) to be used, and communication can be realized in runtime.
Therefore, the burden on the PLC user program is greatly reduced. When designing the system, directly specify the address of the input/output (i/o), register (R), and intermediate register (M) of the control unit and its corresponding PLC. When running, HMI can automatically exchange data with the PLC. Directly read or rewrite the content of the corresponding address of the PLC, and change the display content on the interface accordingly. At the same time, by touching the HMI, data can be input to the corresponding address of the PLC.
3, HMI monitoring main interface
The entire HMI monitoring system adopts a tree structure, which consists of a monitoring and adjustment interface (as shown in Figure 1) and corresponding functional sub-interfaces.
There are control function keys on the monitoring main interface. Touching each function key can enter the corresponding sub-interface and perform the required functions.
In each sub-interface, the interface can be switched in the same function group through the I-PrevI, I-I-I function keys. In any sub-interface, you can return to the monitoring main interface by pressing l to return to the function key. The system automatically collects relevant data and displays the working status and some process parameters of the equipment on the main interface, which is convenient for the operator to observe. The monitoring interface and the dynamic interface of the production process are shown in Fig. 2. In the dynamic interface, the operation of the main control equipment is simulated in various forms, such as the position of the equipment, grinding status and grinding data, etc. Vividly reflects the presence of the field, to facilitate the operator's understanding of production conditions, equipment conditions d HMI programming software Easy Builder provides a wealth of control components; such as button components, interface switching components, indicator components, data text display components and Animated widgets and more. To achieve the above functions, select the appropriate control component as required and define its attributes. Easy Builder adopts the monitoring software common mode, and the properties of all control components are completed through the configuration to realize the corresponding control functions. Using the gallery and drawing tools included in Easy Builder to construct the simulation interface on the production site is simple and easy.
In addition, taking full advantage of the HMI's advantages, the switches, buttons, and indicators that were originally placed on the control cabinet are replaced with the control components in the HMI as much as possible, which reduces hardware, simplifies wiring, and reduces failure rates.
4, HMI parameter settings
There are many process parameters need to be set and changed in the function master control system. According to the control function, the grinding parameters that often need to be changed are made into several interface parameter groups (see Figure 3), so that the structure of the entire system is more reasonable. At the same time, the use of touch operation features makes parameter settings extremely simple and intuitive. In the parameter setting, you can touch the function key to enter the parameter setting interface, and use its internal digital number keyboard to design this numeric keypad as a popup. When the operator wants to set the parameters, touch the desired parameter to change. The number keys pop up the numeric keypad to operate. Each data in the HMI is defined in the component properties and assigned the corresponding PLC address. After the numbers are input in sequence, press the scl key and the numeric keypad disappears.
The entered data is confirmed to be stored in the address specified by the PLC. At the same time, each parameter value is allowed to have upper and lower limits. When the input value exceeds the limit, the system refuses to accept and send an alarm to the operator and returns to the previous data. In addition, the important system equipment parameter group is not allowed to be modified. The Easy Builder software tool library can be used to password protect the modification of the setup interface parameters to increase the security of the system.
At the same time, its control methods, operating levels, and intuitive personalized operating performance requirements are also increasing. Therefore, the interactive operation interface, alarm records and printing requirements also become important content of the entire control system. For an industrial control system with a complex process and a large number of control parameters, it is particularly important. Therefore, the appearance of the industrial HMI and HMI provides a convenient and feasible human-machine dialogue path for the realization of the above functions in the construction of the PLC control system, providing a better choice for the transformation of the grinder industrial control system.
The features and functions of the industrial man-machine interface, also known as touch screen monitors, are an operation control display device. Its hardware consists of a power supply, a touch resistor network, a display, memory, and an IYO expansion interface. The HMI is based on a specially designed computer system (32-bit RISC CPU chip). A transparent resistive network touch screen is mounted on the STN, TFr liquid crystal display, or EL (Electro Luminescence) display. When the screen is touched, the resistance and voltage on the resistor network change and the touch position is calculated by the software.
The main functions are: input and display of data, real-time information display of the operating status of the system or equipment, setting the touch control on the HMI can be used as the operation panel to control the operation, alarm processing and printing; in addition, the new generation of HMI also has a simple Programming, input data processing, data logging and recipes, and other intelligent control functions.
Application on PLC Industrial Control System
1, system overview
The automatic cycle of the grinding machine includes loading, magnetic, quick jump, fast trend, black skin grinding, coarse movement, fine movement, and light grinding.
The original configuration of the control system for the UCN281 small industrial computer, due to its poor stability, high failure rate, often cause equipment downtime. During the retrofitting process, the system hardware was changed to consist of PLCs and detection instruments. The field device control devices consisted of stepper motors, harmonic reducers, ball screws, and the like. Under normal circumstances, according to the requirements of the production process, coordinate the work of each grinding process control system, set grinding parameters, and achieve full automation of the entire grinding cycle. The core control part of the whole system is implemented by OMRON, and the system's monitoring and interactive operation interface tasks will bear the HMI. The main contents are as follows: Parameter setting, dynamic screen display, parameter display of grinding process, fault alarm and diagnosis. Among them HMI chooses step-by-step e-VIEW-506L.
2. Communication between HMI and PLC
When the HMI is used in a PLC control system, the HMI communicates with the PLC via a serial port in a D-LINK (direct connection) mode. In this mode, the HM I reads the PLC data directly or writes the data to the corresponding PLC address. Because of the built-in communication protocol, there is no need to compile the communication program. Just specify the type (ie, communication protocol) to be used, and communication can be realized in runtime.
Therefore, the burden on the PLC user program is greatly reduced. When designing the system, directly specify the address of the input/output (i/o), register (R), and intermediate register (M) of the control unit and its corresponding PLC. When running, HMI can automatically exchange data with the PLC. Directly read or rewrite the content of the corresponding address of the PLC, and change the display content on the interface accordingly. At the same time, by touching the HMI, data can be input to the corresponding address of the PLC.
3, HMI monitoring main interface
The entire HMI monitoring system adopts a tree structure, which consists of a monitoring and adjustment interface (as shown in Figure 1) and corresponding functional sub-interfaces.
There are control function keys on the monitoring main interface. Touching each function key can enter the corresponding sub-interface and perform the required functions.
In each sub-interface, the interface can be switched in the same function group through the I-PrevI, I-I-I function keys. In any sub-interface, you can return to the monitoring main interface by pressing l to return to the function key. The system automatically collects relevant data and displays the working status and some process parameters of the equipment on the main interface, which is convenient for the operator to observe. The monitoring interface and the dynamic interface of the production process are shown in Fig. 2. In the dynamic interface, the operation of the main control equipment is simulated in various forms, such as the position of the equipment, grinding status and grinding data, etc. Vividly reflects the presence of the field, to facilitate the operator's understanding of production conditions, equipment conditions d HMI programming software Easy Builder provides a wealth of control components; such as button components, interface switching components, indicator components, data text display components and Animated widgets and more. To achieve the above functions, select the appropriate control component as required and define its attributes. Easy Builder adopts the monitoring software common mode, and the properties of all control components are completed through the configuration to realize the corresponding control functions. Using the gallery and drawing tools included in Easy Builder to construct the simulation interface on the production site is simple and easy.
In addition, taking full advantage of the HMI's advantages, the switches, buttons, and indicators that were originally placed on the control cabinet are replaced with the control components in the HMI as much as possible, which reduces hardware, simplifies wiring, and reduces failure rates.
Figure 2 Dynamic interface during production
image 3
4, HMI parameter settings
There are many process parameters need to be set and changed in the function master control system. According to the control function, the grinding parameters that often need to be changed are made into several interface parameter groups (see Figure 3), so that the structure of the entire system is more reasonable. At the same time, the use of touch operation features makes parameter settings extremely simple and intuitive. In the parameter setting, you can touch the function key to enter the parameter setting interface, and use its internal digital number keyboard to design this numeric keypad as a popup. When the operator wants to set the parameters, touch the desired parameter to change. The number keys pop up the numeric keypad to operate. Each data in the HMI is defined in the component properties and assigned the corresponding PLC address. After the numbers are input in sequence, press the scl key and the numeric keypad disappears.
The entered data is confirmed to be stored in the address specified by the PLC. At the same time, each parameter value is allowed to have upper and lower limits. When the input value exceeds the limit, the system refuses to accept and send an alarm to the operator and returns to the previous data. In addition, the important system equipment parameter group is not allowed to be modified. The Easy Builder software tool library can be used to password protect the modification of the setup interface parameters to increase the security of the system.