HMIs Enable Mobile Support
EP Editorial Staff | May 12, 2021
Human-machine interfaces are often the best choice to provide mobile access and monitoring capabilities for industrial operations.
By Linda Htay, IDEC Corp.
Industrial-equipment end users are increasingly calling for their machines and systems to provide mobile access and monitoring capabilities, much like consumer-grade devices. Yet there are many connectivity, networking, and security challenges with implementing mobile services at a typical manufacturing plant.
In most instances, mobile functionality is desired to allow remote personnel to operate and maintain assets so operating data can be gathered and visualized. This is the case for new and existing systems.
With the correct industrial-grade products, end users and original-equipment manufacturers (OEMs) have several options for delivering various levels of mobile access and monitoring solutions. In particular, human-machine interfaces (HMIs) effectively provide flexible, full-featured, and secure mobile access and monitoring.
Establishing a mobile-connectivity solution rarely is a one-size-fits-all project, especially for industrial equipment. In the field, several controllers, sensors, and industrial-communication protocols are involved. Even once the source data is obtained, it must be made accessible by mobile devices over the local IT network or through a cloud-based system.
In some cases, bulk downloads of stored data may be required. When mobile visualization is needed, some end users only require a basic dashboard, while others want a more comprehensive view, usually using a browser. For many situations, a mobile app will quickly and easily present the essential information. With other users, brief email warnings are sufficient.
While there are similarities among each of these options, particularly with initial data acquisition, transmitting and presenting the information involves many variations. Because an industrial HMI is built for field conditions and is easily installed at the operational edge, it can be the best platform for multiple mobile access and monitoring roles.
Some machines or systems produce periodic collections of data, such as from a production run, a daily summary, an alarm log, a data log, or a batch operation. In these cases, it usually doesn’t make sense for users to view the data directly. Most would prefer to receive a data file that can be archived and/or viewed at a later date.
By including support for file-transfer protocol (FTP), an HMI can collect data and then act as an FTP client or server to transmit files to an external memory device or cloud-based storage. FTP can also be used by remote personnel to transfer program configurations, with no other HMI software needed. FTP access may require IT network or firewall settings so local or mobile users can connect to the HMI network. Once configured, FTP can be a convenient, efficient, and bandwidth-friendly remote-data-transfer method.
In many cases, an HMI with web-server capability provides the best mobile-user experience for two key reasons. The first is that the mobile person can use any device capable of hosting a web browser—smartphone, laptop, or tablet—so no extra or specialized software needs to be installed on the device. The second reason is that the device view is the equivalent of standing in front of the HMI on the factory floor.
Whether the mobile user is an operator, supervisor, or a maintenance technician, they can perform operational, troubleshooting, and maintenance tasks from anywhere, without the time and expense associated with travel. Personnel in a central location can support many different facilities or remote locations.
An HMI with web-server functionality should be able to display system information, provide remote monitoring, and even enable remote control. Standard web pages replicate native HMI screens, but some users may choose to create custom web pages, so a drag-and-drop editor with pre-built images is helpful.
Web-server functionality requires IT personnel to configure the local network and firewall to allow mobile access. Another possible issue arises if the HMI uses a cellular data connection, because high data usage and associated costs can result if remote users remain connected for extended periods, intentionally or accidentally. To avoid costly data usage, a web-server automatic timeout function is recommended.
Another capable remote option, especially for maintenance personnel, is using a mobile app offered by the HMI supplier. An app is easy to operate on any user’s mobile device and provides methods for uploading and downloading system software, files, and folders. The user can also view status information and directly monitor device addresses.
A mobile app is particularly effective for supporting a fleet of installed HMIs and programmable logic controllers (PLCs). Once the app is configured for network access and the target IP address list is created, the user can simply click through to the device of interest.
An HMI with email functionality might be the most straightforward method of connecting with one or multiple mobile users. Each email can be a simple static text message indicating the system status. More-complex information can be embedded with or attached to the email, such as:
• dynamic PLC or HMI values
• alarm or operation logs
• data files
• HMI screenshots.
At minimum, these HMIs need internet access. They also should support SMTPS and SSL secure connections and use any popular email service.
Enabling mobile access to any industrial-automation system, whether through email or other methods described above, usually calls for IT attention to networking, firewall, and internet connectivity settings. Users must ensure that the target devices they select, such as HMIs and the mobile methods and apps used to connect with them, include built-in provisions for typical IT security protocols and support complex passwords.
Making Mobile Connections
End users at plants or supporting remote locations have a critical need for remote-access and monitoring options. Whether they operate water-treatment systems, machine tools, food-processing equipment, packaging machines, or other facility assets, industrial automation is present almost everywhere and can provide valuable information, if users can make the mobile connection.
Today, HMIs are available with bright, high-resolution screens and wide operating-temperature ranges, making them suitable for use almost everywhere. The most capable models carry IP66F/67F, UL61010, Type 4X/12/13 approval ratings, and are even suitable for installation in Class I Division 2 hazardous locations, as well as marine applications. For additional insurance, even HMIs built for endurance should be backed by long, multi-year warranties. They already provide valuable local visualization and incorporate popular industrial protocols, such as Modbus TCP/IP, so they can act as communication gateways for many devices.
With the right features, HMIs are ideal platforms for delivering information to mobile users. This connectivity enables maintenance functions such as status monitoring and program uploads/downloads. It can also support operational access to the information and data files personnel need to keep even the most far-flung systems running efficiently. EP
Linda Htay is Product Marketing Specialist at IDEC Corp., Sunnyvale, CA (us.idec.com), where she is responsible for touchscreen and display products. Htay has more than 15 yr. of experience working with automation and industrial products such as HMIs and PLCs. She holds a degree in Electrical Engineering.