A new device provides an ergonomic and secure way for designers to harness the networking and operator interface capabilities of modern tablets when used with industrial equipment requiring safety provisions.
By Luiz Shida, IDEC Corporation
Dedicated human-machine interfaces (HMIs) and PCs, whether installed in a panel or a control room, have played an important role in providing robust operator interfaces for industrial applications. However, crewed equipment, robotics, and other manufacturing automation systems require hardwired safety provisions, such as emergency stop (e-stop) and enabling switches, in addition to digital interfaces. There is also a great need for flexibility so operators can access these HMI and safety features while moving around equipment, which fixed installations can’t provide.
Some OEMs and automation designers have used hardwired pendant controls to partially address the problem. Others have incorporated wireless mobile devices for a modern and portable HMI solution, but this approach lacks the hardwired safety required for many systems.
A new option is now available so designers can provide consumer mobile devices as high-performance HMIs, with the hardwiring and secure physical protection needed for industrial applications.
Tablets on the factory floor
Most industrial operations personnel are familiar with the constraints of using specialized HMIs installed in fixed locations or working with a pendant interface offering limited functionality. For some applications, these methods are acceptable.
However, there are many cases where user mobility around controlled equipment benefits operations and maintenance of dynamic hardware. Some examples are applications with traditional robotics, collaborative robotics, automated guided vehicles (AGVs), autonomous mobile robots (AMRs), and other manufacturing and material-handling equipment.
Modern consumer-grade tablets provide users with a rich HMI visualization experience, especially for data-intensive Industrial Internet of Things (IIoT) applications. They can also do many other things, such as display drawings and manuals, show analytics results and reports, provide web browser views, and even support videoconferencing with other personnel and specialists.
Figure 1: Modern consumer-grade and ruggedized tablets offer the display size and computing power OEMs and designers need for flexible and mobile HMI interfaces but are only practical if the tablet can be protected and if the necessary power, networking, and safety/control hardwiring are available.
But these devices won’t last long when used in harsh industrial conditions and cannot support hardwired safety requirements.
Improving the mobile HMI experience
Some end users have experimented with using consumer electronics for industrial applications, with mixed success. Responding to the market need, one industrial automation supplier developed an ergonomic device to hold and protect an HMI tablet. This device was adopted by many designers and OEMs to rapidly deploy a convenient way for protecting and using a tablet for industrial use.
The original mobile device holder for industrial use remains available. It offers some hardwired connectivity and relies on Bluetooth or Wi-Fi for wireless communications, which works well in many applications. Standard features include:
- Ability to use the tablet in vertical/portrait or horizontal/landscape orientations.
- Users can insert or remove the tablet at will or lock it into place for longer-term use.
- Suitable for left- and right-handed users, with a hand or shoulder strap to minimize fatigue.
- Availability of a wall-mount bracket.
- Rated IP54 for protection from water splashes, dust, and dirt, with an operating temperature of -10 to 35° C or more.
- Tested for drop resistance up to 1.2m.
- Includes hardwired power, e-stop, and enable switch functionality.
However, users were asking for additional enhancements to use this approach in even more applications, especially those seeking compliance with ISO/IEC safety standards and requirements. For example, many users must design to meet ISO 10218, which addresses robots, collaborative robots, and their integration. With a large installed base, some of these users have requested additional features to expand the use of commercial tablets as flexible industrial HMIs (Figure 2).
Figure 2: IDEC’s new HT4P Safety Commander lets designers incorporate tablets into industrial environments, with enhancements such as the ability to hold large and powerful tablets, wired power and networking, and hardwired safety and non-safety buttons and switches.
Larger tablet size
Commercially available tablets have increased in physical display size and CPU processing performance over the years, and some ruggedized versions are available. Many industrial users find that tablets up to 13 in. are the best fit to provide enough visualization display area and computing power. Modern tablets offer a significant price advantage compared to traditional industrial touch panels.
Therefore, the newest mobile device holder uses adjustable grippers with movable hooks and spacers, so larger tablets can be used while preserving access to power, audio buttons, and other ports. A new rotation unlock button ensures the tablet only rotates when the user wants it to, preventing unintentional operation.
Wired power and networking
Designers can still choose to use Bluetooth or Wi-Fi for their applications. However, in some environments — particularly those with high electrical noise — an onboard wired LAN connection is preferred for faster and more reliable communications. Most tablets don’t have a built-in wired LAN port. The previous mobile device holder included a USB Type-C power connection, so the tablet remained charged for continuous operation. The newer version goes a step further by incorporating a built-in LAN converter so that the USB tablet port can access a wired network.
Hardwired non-safety switches
Two hardwired safety features remain incorporated into the device. An e-stop button with an LED indicator, with a retrofittable guard to protect against unintended operation, is available for connection with a standard equipment safety circuit. In addition, a three-position “off-on-off” enable switch is essential for many equipment and robotics applications. The user must constantly grip this switch with moderate effort for the equipment to run. If they let go or squeeze too hard in a panic situation, the equipment will stop.
The newest mobile device holder now allows additional hardwired device functionality by including three onboard mounting positions capable of providing standard or custom arrangements of pushbuttons, illuminated pushbuttons, selector switches, and keyed selector switches.
Cable options
Designers need cable options of sufficient length but not so much excess as to cause an issue. The new mobile device holder uses a tough-yet-flexible shielded cable with incorporated strain reliefs, and it is available in lengths of 5 m, 10 m, 15 m, and 20 m.
Combining consumer tech with industrial safety
One inexpensive tablet can replace numerous industrial control panels, HMIs, and other buttons and lights. However, this is only practical if users can easily carry the tablet and protect it from damage (Figure 3). In addition, most types of operating equipment require some degree of hardwired safety elements such as e-stop buttons and enable switches, and many applications benefit from other hardwired networking, control, and indication components.
Figure 3: Safety and ergonomics were prime considerations in developing the newest generation of IDEC HT4P Safety Commander.
A new generation of mobile device holders expands upon previous options, providing more ways for OEMs and equipment designers to take advantage of modern and familiar tablets acting as HMIs located close to machinery. Users of these types of devices will benefit from greater flexibility and equipment visibility, while designers can ensure compliance with safety standards and requirements.
IDEC
idec.com
You may also like:
Filed Under: IoT • IIoT • Internet of things • Industry 4.0, NEWS • PROFILES • EDITORIALS, Industrial automation, Displays • HMIs • operator interfaces • monitors, INDUSTRIAL SAFETY SYSTEMS
