The latest generation of HMI combines the best functions of traditional products with modern open source hardware, software and network technology to solve the challenges faced by traditional products.
Operator interface equipment is the key element of industrial automation, but many products have shortcomings and implementation obstacles. With the integration of new features such as firmness and ease of use, the operator interface equipment is applied to industrial edge and other key applications, and the best function of classic human-computer interface is combined with modern commercial technology.
The electronic devices that allow the operator to interact with the automation system are collectively referred to as human machine interface (HMI). Sometimes, a more specialized device built on a non personal computer (PC) computing platform may be called an operator interface terminal (OIT). It is very important to integrate HMI and operator interface terminal into automation system. They can provide more interface options than simple panel devices, and can usually reconfigure or reprogram HMI or operator interface terminals at a lower cost if they need to be changed.
However, some additional operator interface functions still have some shortcomings, which make the cost of HMI too high and difficult to maintain. In order to solve these shortcomings, the design of the latest HMI products absorbs the past experience and utilizes the latest commercial technology.
01. Challenges of traditional HMI
The first generation of HMI and operator interface terminal focus on enabling users to start and stop the equipment, understand the operation mode of the system and make appropriate adjustments.
Alarm and event recording, historical data and display trend are gradually added later. HMI and operator interface terminal configuration can be copied and saved. If the old equipment is damaged or fails, new equipment can be deployed relatively quickly. Improved network capabilities, especially ethernet and Wi Fi, mean that the HMI no longer needs to be installed physically close to the machine. Multiple HMIS can be installed on site to provide interfaces in control rooms, machines and offices.
Compared with hardwired panel devices, these HMI and operator interface terminals have many advantages, but also some disadvantages.
The challenges include:
·Restrictions on proprietary hardware and software;
·The initial cost is high;
·Continuous support and maintenance costs;
·Licensing complexity and cost;
·Extensive engineer and operator training;
·Efforts required to integrate multiple platforms;
Dedicated operator interface terminals may use proprietary hardware and software (see Figure 1). The manufacturer provides these devices to provide sufficient control system interfaces in a relatively independent space. Because they are dedicated to the industrial market, they can not benefit from the commercial benefits of scale provided by consumer electronics products, which makes them less competitive in terms of cost performance. However, they can usually withstand harsh industrial environments and provide practical and maintainable solutions.
Figure 1: operator interface terminals, often used in proprietary and closed systems, are rapidly being replaced by more open systems. Photo source: OPTO22
With the introduction of more advanced PC based HMI, hardware is considered to be more valuable than previous solutions, providing flexibility and connectivity for users. However, it also has a disadvantage, that is, it adds continuous maintenance and support requirements.
Nowadays, users want elegant appearance, frequent free updates, and improvements to the device’s operating system and Applications (Figure 2).
Figure 2: with the popularity of advanced consumer electronics products, end users expect to have rich and intuitive human-computer interfaces and convenient mobile access functions on all types of devices. Groovedge appliance is an Ethernet and USB plug-in device that allows designers to build connection and data processing applications for automation devices and IOT devices.
But compared with the larger consumer market, the innovation speed of the industrial market is a little slower, because its market is relatively small, let alone more conservative compared with the personal electronics market which is on the cutting edge of technology.
02. Latest HMI Technology
The latest generation of HMI products solve these defects through the integration of mature commercial technology. At the same time, it contains and constructs the best functions of previous generations of HMI and operator interface terminal.
The advantages include:
Open source: ideally, modern HMI combines the robustness and ease of use of traditional operator interface terminals with the functionality and value of PC based HMI. When the hardware platform is based on a real-time open source operating system such as Linux, this combination becomes possible without the need for procurement or licensing fees. Small footprint, hot swap components, local LED indicator and other practical touch functions make the platform more suitable for field use. Reasonable design, even in the challenging industrial environment, hardware can provide PC level performance just as it is used at home.
Affordable configuration: customizable, but not required, as modern HMI hardware includes built-in standard features to meet most needs. The price of HMI configuration software based on PC is reasonable and there is no restrictive license fee. The end user can focus on applying the HMI to the most suitable location without worrying about limiting the tag count or runtime.
Ease of use: development tool options not only make it easy for new developers to create basic applications using modern HMI, but also allow advanced programmers to develop custom applications using optional secureshell access. OEMs often need this type of flexibility to write machine specific programs, even proprietary algorithms in C + + / C + +, python, and other languages.
Integrated screen and flexible port: the on-board display provided on some devices can provide much more HMI than required for applications, but HDMI can provide larger local display as required. In addition, multiple Ethernet and USB ports and I / O modules facilitate connectivity to any field device or system.
Network and cloud based connection: when users use network and cloud based connection, they can realize more functions from modern HMI. Data can be safely shared between database and system, and HMI visualization can be extended to any authorized computer or mobile device that can host web browser.
Mobile devices: mobility is another key component of modern HMI. Once the infrastructure is installed and configured, any mobile device can safely connect and become another HMI, providing greater flexibility for engineers and operators.
Designers can pay more attention to what HMI content and experience should be, while reducing the cost and complexity of the underlying platform. The latest generation of HMI combines the best functions of traditional products with modern open source hardware, software and network technology to solve the challenges brought by traditional products.
Because these latest HMIS can be easily and seamlessly networked and deployed to any typical mobile device, end users find that today’s technologies are meeting their needs at affordable prices.
Editor in charge: yyx