RFID authentication devices on OEM machinery ensure the proper users are taking permitted actions, providing performance benefits and improved safety.
Byline: Linda Htay, IDEC Corporation
Automated equipment and machinery can incorporate many ways for users to monitor and control operation, such as with buttons, switches, and touchscreens. When original equipment manufacturers (OEMs) design and build their machinery, they want to deliver easy-to-use functionality. However, they must carefully balance this desire with the need to verify authorized users are at the controls and making acceptable selections.
Several authentication methods are possible, ranging in the security levels, user convenience, and features they provide. The simplest schemes may not offer enough protection, while the most complex usually are expensive and limiting.
Balanced solutions provide strong security and audit logs—and they are simple to implement, cost-effective to maintain, and easy for end users to work with. This article will discuss developments in the area of using radio-frequency identification (RFID) in and on machinery and equipment for managing user authority, providing traceability, improving safety, and reducing paperwork.
Authentication Drivers
It is certainly possible to design machinery void of authentication methods, just as a car could be built with an on/off switch instead of an ignition key, or a house with no locks on its doors. Just as there are logical reasons to implement authentication solutions on cars and houses, there are motivations for doing so on industrial machinery, such as achieving operation restriction, traceability, or both. Sometimes these motivations are driven by technical initiatives, but often they are mandated by regulatory requirements.
Operation restriction can sound negative, so operation permission may be a better term. OEMs and end user manufacturing companies incorporate authentication methods to ensure proper personnel are accessing machinery controls, but they do not wish to limit authorization to a binary yes or no. Authentication extends into defining groups of personnel and even individuals, with granular selection of what machinery information they can view and adjust.
Some companies may proactively add permissions to better ensure safe and proper equipment operation. In other cases, compliance with industry safety standards such as ISO16090 (for machine tools) or ISO10218-1 (for industrial robots) can lead to adopting authentication methods.
Traceability drivers involve gathering data, and manufacturers can use authentication to log which users operated a machine and the actions performed. This history may be used for informational purposes, which a company can analyze with the goal of improving performance. Or, the data trail may be stored to satisfy an industry requirement such as FSSC22000 for food safety, which calls for traceability in the manufacturing process.
Methods for Security
Several levels of security are possible, each with a range of benefits, disadvantages, and costs. The following methods are suitable for adapting into industrial machinery use, and are familiar to most consumers:
- Physical/mechanical keys
- Magnetic strip cards / swipe cards
- Passwords
- Biometrics
- RFID
Physical keys are the oldest and most familiar of the authentication methods. They are simple and low cost, but easy to copy or lend. OEMs can implement a basic key switch into their machine, but it only provides a binary or limited selection by any user who gains access to the key. Magnetic strip cards are an improved version of physical keys, which add some digital capability. However, they may not be convenient to carry and protect at industrial sites.
Modern digital devices used for industrial machine automation—including PCs, human-machine interfaces (HMIs), and mobile devices—have made passwords a common authentication method. Passwords can provide a limitless number of authentication levels per user, and are relatively inexpensive to manage. Unfortunately, they can be forgotten or leaked, and they can be difficult to use in many industrial settings where gloves are used or where a full keyboard or touchscreen may not be available.
Biometrics are common in consumer electronics and some commercial applications. Fingerprint and face scanners are some examples. Because they use personal and non-transmittable information, they are relatively secure, do not require operators to carry or remember anything, and typically cannot be duplicated or lent out. Unfortunately, biometric techniques are relatively expensive to implement and manage, and they don’t work well around machinery where gloves, helmets, masks, and safety glasses may impede their function.
This brings us to the RFID method, which occupies a sweet spot within industrial machinery authentication. RFID tags are familiar to most anyone who has used a parking lot or building access system. They are simple and relatively inexpensive to manage, and they are not easily duplicated. Although they are easy to lend, authentication can be modified quickly because they are digitally managed. As a robust physical token, RFID tags and sensors are readily implemented for industrial applications.
Industrial-Specific RFID Devices
RFID is a preferred technology for many applications because the user’s tag is passive, meaning it is lightweight and does not require batteries. Reader devices, typically installed in a fixed location, generate a radio signal, causing a passive tag in range responds with a unique signal.
Consumer-grade RFID readers commonly found in commercial applications are fairly robust, but they usually are not built to withstand the temperature, vibration, and washdown/chemical environments associated with many machines. Most of these readers are designed to use rectangular cutouts, which are not convenient for many control panel designs.
On the contrary, certain industrial-grade RFID readers are explicitly designed to fit industrial-friendly common control panel form factors, such as the 22mm knockout hole (Figure 1). Furthermore, these devices are available with IP67 ratings, meaning they are protected from dust, low-pressure water jets, and even immersion situations sometimes found with industrial installations.
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