By separating the control unit, which runs the display and control programs, and the communication unit, which accesses the devices under control, modern panel PCs can address a wide range of industrial, medical, transportation and other control applications.
BY CY HUNG, ADLINK TECHNOLOGY
The Industrial PC (IPC) industry is a competitive and demanding market that continues to evolve with a wide variety of solutions. Relative to traditional automation applications, the maturation of PC and networking technologies has enabled the IPC industry to expand into new vertical markets, such as automotive, medical and information technology (IT). Across markets, smart control has become a key aspect of today’s IPC system designs, where the central control unit can operate with a longer up-time, lower power consumption and low radiation emissions, and must be built to industrial grade standards (Figure1).
In an IPC design, the control unit can be viewed as the command center for directing traffic and data transfers between individual devices within a system. Today, embedded systems and general purpose systems form the two major directions for IPC design and overall advancements in computing technologies. The control unit can be further classified into single board (main board, module board) and equipment categories, whereas the Panel PC and Box PC are differentiated by the level of integration of the system. Evolution of the control unit is an ongoing process that conforms to a wide variety of market demands. While the general purpose PC design is focused on pushing for more speed and compute capabilities, industrial embedded system design offers added complexity through restrictions on form factor and requirements for longevity and remote control capabilities.
The Panel PC is currently constrained by the single board control unit and lacks the necessary expandability and customization features to meet industrial application demands. Thus, up to this point, customized systems have been developed from scratch in order to accommodate specific application requirements. However, over the past several years, commercial off-the-shelf (COTS) displays have evolved into highly integrated smart control units, or smart panels, that offer expansion capabilities for customization, as well as small form factor (SFF) and low power board designs suitable for embedded IPC systems (Figure 2).
Today’s COTS all-in-one smart panel systems offer high flexibility and reliability with SFF I/O boards and expansion ports.
Ultra-Low-Power SMARC Offers New Possibilities in SFF Design
In terms of small form factor offerings, computer-on-modules (COMs) are an attractive option for IPC designs. One of the most recent COM standards, Smart Mobility Architecture (SMARC), was developed to provide a smaller profile and lower power alternative to current COM standards—such as COM Express—in order to develop ultra-low-power applications for small, thin form factor mobile or stationary devices, such as instrumentation, emergency medical devices, industrial tablets and human machine interfaces (HMI).
The SMARC standard was established by the Standardization Group for Embedded Technologies (SGET), comprised of leading embedded companies and including ADLINK. In its initial stage, SMARC merely defined the standard processor architecture of ARM and system on chip (SoC). However, with the launch of SoC for x86, which offers much lower power consumption, the industry will see a more rapid response to the standard and market demands for the SMARC with x86 SoC combination.
As an example of a COTS smart panel design, a SMARC dual module design can feature a single board CPU module (SMARC module) connecting to a baseboard through a 314-pin B-to-B connector. The SMARC module is 82 x 80 mm and designed for low power consumption and high expandability. Although market demand dictates the application of either an embedded or general purpose system, the SMARC design with dual module configuration is able to fulfill a wide range of system requirements for both types of systems. For instance, in automated automotive control applications, the onboard embedded system can be used for monitoring and information feedback on an individual vehicle; whereas, a general purpose system is better suited for processing a fleet of vehicles for real-time monitoring of driver and vehicle behaviors.
The baseboard can be designed around the control unit to include the basic I/O ports (USB, LAN), wide input voltage (e.g., 9-36 VDC input), touch control chip and communication modules such as Wi-Fi, Bluetooth, high-speed uplink packet access (HSUPA), LTE etc. based on customer specifications. Furthermore, this baseboard can also offer expansion ports to support additional applications after designs are finalized. In industrial automation systems, the power source can be isolated with a connector board to avoid unnecessary damages and losses. In home automation systems, the digital or analog I/O board can be designed with various switches to corresponding signals. These are just some examples of the flexibility and versatility offered by the dual-module design with expansion ports that can quickly fulfill customer and market demands (Figure 3). Thus in an industrial automation scenario, for example, each segment can use different embedded control units based on diverse mission requests to reduce costs. Because high-performance computational needs and capabilities are required by master control, standard control units can be used for real-time messaging (Figure 4).
The SMARC design with dual module configuration will be able to fulfill a wide range of system requirements
Example of an industrial operation where different stages can take advantage of different control unit configurations.
While the SMARC module offers performance upgrade options, system reliability and stability are also key aspects of the control unit, which smart panel design can address through cooling and fan modules. The fanless SMARC module dissipates heat through the metal casing. Even with the low power consumption design, the choice of metal and thermal coefficient is critical for an effective cooling performance. Using an aluminum magnesium alloy with cooling fins on the back plate can quickly remove heat from the source and improve product stability. As the SMARC module houses the main sources of heat (CPU and RAM), thermal and casing designs can be simplified with reduced time-to-market for customers.
Control & Communication
Driven by the IT revolution, HMI has evolved from the man-machine interface (MMI) of the 70s and the human-computer interface (HCI) to greatly change our lives and professional careers following the industrial revolution. From the earliest text interface with keyboard and mouse, to the touch interfaces of today’s products, the HMI has been continuously revolutionized and refined.
Today’s smart panel designs offer control and communication interfaces to guarantee consistency and visibility for the operator. The control interface is enabled by a resistive or capacitive touch screen. Resistive technology relies on a drop in voltage in a pair of X and Y driver circuits due to pressure exerted on the touch screen. The controller then calculates the coordinates by the voltage drop ratio. In other words, coordinates are calculated from the change in current due to exerted pressure on the touch panel. A capacitive touch screen features a screen surface coated with a capacitive material, forming a uniform electric field discharged from the four corners. Once a conductive object (e.g. the human finger) comes into contact with the panel surface, a small amount of current flows onto the object, changing the capacitive properties. The controller then calculates the X and Y coordinates by the current flow ratio. The communication interface offers low, intermediate and high-end display panels. For example, the high-end displays feature higher brightness and better visibility for outdoor applications or on a ship/vessel.
Overall, today’s smart panel technology greatly improves control unit design in order to offer a higher degree of customization to both embedded and general purpose IPC systems. Generally speaking, the levels of smart controls and performance are the main criteria when selecting a controller, and current smart panel designs offer complete, integrated, intelligent solutions for fast time-to-market.
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