HMI touch screen, also known as "touch panel", is an inductive liquid crystal display device that can receive input signals such as contacts.
When user touches the graphic buttons on the screen, the tactile feedback system on the screen can drive various connecting devices according to the pre-programmed software, which can replace the mechanical button panel. And the LCD (Liquid Crystal Display) screen can create dynamic audio-visual effect.
As a new computer input device, HMI touch screen is the most simple, convenient and natural way of human-computer interaction. It gives multimedia a new look and is a new attractive multimedia interactive device.
At present, it is mainly used in public information inquiry, leadership office, industrial control, military command, electronic games, ordering songs and dishes, multimedia teaching, and real estate pre-sale services, etc.
Figure 1: Delta HMI HMI DOP-07S515
The HMI touch screen is under a completely isolated working environment. It is resistant to dust, steam and oil.
It can be touched by any object and can be used for writing and drawing.
The precision of resistive HMI touch screen only depends on the precision of A / D conversion, so it can easily reach 4096 * 4096 pixels. Comparatively speaking, the 5-wire resistance is superior to the 4-wire resistance in ensuring the resolution accuracy, but its cost is high.
For the convenience of operation, people use HMI touch screen instead of mouse or keyboard.
First, touch the HMI touch screen installed on the front of the display with fingers or other objects, and the system will locate and select information input according to the icon or menu position touched by fingers.
The HMI touch screen consists of a touch detection unit and a HMI touch screen controller. The touch detection part is installed in the front of the display screen to detect and receive the user's touch position, and sends it to HMI touch screen controller.
The function of the HMI touch screen controller is to receive the touch information from the touch point detection device, and convert it into contact coordinates. Afterwards the HMI touchscreen controller sends it to the CPU. At the same time, it can accept and execute the commands from the CPU.
HMI touch screen is widely used worldwide, mostly for public information inquiry. It includes the business inquiry of the telecommunication bureau, tax bureau, bank, power department, and information query on the streets of the city.
In addition, it is also used in offices, industrial control, military command, video games, ordering songs and dishes, multimedia teaching, and real estate pre-sale services etc.
In the future, HMI touch screens will be in our home. With the increasing use of computer as the source of information, the HMI touch screen is easy to use, durable, fast to respond, and space saving, so that more and more system designers feel that using the HMI touch screen is indeed quite superior.
HMI touch screen has been in wide use for only a few years. This new multimedia device has not been contacted and understood by many people, including some system designers who are planning to use HMI touch screen, and also regard HMI touch screen as an available device. From the perspective of the popularization of HMI touch screens in different countries and in different economy development stages, the concept of using HMI touch screen has a certain universality.
As a matter of fact, HMI touch screen is a device that changes the multimedia information or control. It gives a new look to the multimedia system. And it is an attractive new multimedia interactive device.
The system designers of HMI touch screens have clearly known that this device is no longer a spare thing for computers in various application fields, but an indispensable piece. It greatly simplifies the use of the computer, even people who know nothing about the computer can understand how to use it. It solves the problem that the computer can't solve in the public information market.
Figure 2: HMI touch screen applied in printing.
KingView SCADA software is a new type of industrial automatic control system. It can replace the traditional closed system with an integrated system composed of standard industrial computer software and hardware platform.
Figure 3: KingView SCADA Software (Source from scadasoftware.net)
It has the advantages of strong adaptability, openness, expansion, economy and rapid development cycle. Generally, the KingView system can be divided into control, monitoring and management layer. Among them, the monitoring layer connects the control layer to the lower layer and the management to the upper. It not only realizes the real-time monitoring and control of the site, but also plays an important role in the upload and release of the automatic control system. Besides, it helps configuration development.
Picture, data and animation of three aspects should be especially considered. Through the analysis of the requirements and functions of the monitoring system, KingView software is used to design the monitoring system. The configuration software also provides a visual monitoring screen for the user, which is conducive to the real-time on-site monitoring of the user.
Moreover, it makes full use of the graphics editing function of windows, easily forms the monitoring screen, and displays the status of the control equipment in the form of animation. It owns alarm window, real-time trend curve, etc. And it can easily generate various reports. There are rich device drivers, flexible configuration mode in the KingView system, which also has data link function.
KingView combined with DTP_S09 short message module is used for remote GPRS data transmission.
KingView combined with force control sending SMS alarm equipment.
Now configuration software and HMI touch screen have been mature products in the market. The configuration software will not replace HMI touch screen. They both have advantages in some ways. Both the configuration software and the HMI touch screen need to develop the driver for the connected PLC and other devices, which are used to read and send data. The computer and the HMI touch screen equipped with the configuration software are called the upper computer.
The HMI touch screen is usually connected with PLC (now can also communicate with frequency converter, servo, etc., such as proface); General configuration software can be connected with PLC, instrument, intelligent module, DCS and other devices or third-party software systems. Because it is installed on Windows and other operating system platforms, the function will be more powerful, such as real-time database, etc. It can also combine with relational database for some complex data statistical analysis.
The HMI touch screen is used for local operation of single unit equipment, while configuration software is used for large projects, such as metallurgy, petrochemical, production line, water treatment, etc. Configuration software monitors many points, provides complex picture, and statistical analysis database.
Figure 4: ESA HMI ERGO122
There are many kinds of acquisition methods for configuration software, mainly including wired and wireless mode. The way of wired acquisition is mainly divided into serial port and Ethernet. The acquisition equipment of serial port is mainly collected by polling. The more equipment, the longer the time it takes to collect all data.
Ethernet acquisition is generally done simultaneously. Instead of the number of devices, the actual IO points collected by each device has influence on the acquisition speed. There is a packaging mechanism of configuration software for collecting data. The more data is, the more packets are dozen, the longer the time spent all data packets are queried. For example, compared with a HMI touch screen system, the response speed of configuration software is ms level when the same data is collected.
All configuration software data collection is with delay. Depending on the site situation, the delay is also different. The speed of configuration software and HMI touch screen in controlling PLC is equivalent.