Wirelessly Navigating Robotics: The Role of WLANs in Robotics Technician Work
There’s arguably no other industry that has changed more in the last couple decades than the manufacturing industry. Everything - from SCADA systems, wireless sensors, and articulated autonomous robots - has experienced considerable evolution, all to the benefit of manufacturers the world over. The resulting expansion of operations is intrinsically tied to the manner in which communications and controls are performed throughout the facility - enter Wireless Local Area Networks.
While traditional industrial settings require copious amounts of wiring to connect field devices to control equipment - this leaves facilities somewhat limited in the technological advancements that can be leveraged. In this article, we’ll define WLANs, what benefits they bring to the table, best practices for establishing industrial WLANs, and highlight some of the key technologies that benefit from their use.
What is a Wireless Local Area Network (WLAN)?
In layman’s terms, a WLAN, or Wireless Local Area Network, is a network of wirelessly connected computers and other devices that “talk” to one another using radio transmissions. The manner in which they communicate is through the exchange of labeled packets of information that, in addition to the data itself, contain instructions for proper delivery. Each device in the WLAN has its own unique MAC (Media Access Control) address. When a packet is sent from one device to another the MAC address tells the network what device is the “sender” and which device is the intended recipient.
If you aren’t well-versed in WLANs or the security protocols in place to keep the information transmitted within them safe, you might be wondering, how secure are these networks and how easily could someone intercept the data traveling between two endpoints? Moreover, if they are considered less secure than a wired network, why would a business of any size trust a WLAN with their company’s data? Full disclosure, WLANs can be less secure relative to a wired network. For example, if a WLAN has little to no security a competent hacker could very well intercept the signal that is being broadcast. With a wired network, this same bad actor would need to locate a physical point to access the network or break through a configured external firewall before they could gain access.
It would however be inaccurate to say that WLANs are inherently unsafe and unreliable, or to imply they have no place in a practical business environment where data security is a key factor. The data interception scenario mentioned above can be negated using tried and tested security methods, one of which was already introduced: MAC addresses. Though these addresses facilitate the transfer of information between authorized stations, the same cannot be said for unsanctioned stations. MAC addresses are a great first line of defense - however it is possible for a skilled and determined hacker to “spoof” a MAC address in order to trick the network into thinking their workstation is authorized to exchange data. Fortunately, WLANs leverage additional layers of security to mitigate address spoofing and other methods of unauthorized access in keeping the network safe, the most common of which is data encryption. More often than not, WLANs will be protected by a Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA) encryption. The former encrypts transmitted data using a static 64- or 128-bit hexadecimal key. This is considered a static key because all data being transmitted, regardless of the device, will use the same key. The latter encryption method differs in that it does not use a static key, but rather leverages a temporal key integrity protocol, which dynamically changes the key used by the system. In doing so, it prevents hackers from being able to create their own matching version of a key used by a secured network.
The Benefits of WLANs in Industrial Automation Systems
There are significant benefits to using a WLAN, especially when it comes to industrial automation systems. Many industrial facilities are quite large and it can be quite costly and cumbersome working with wired networks, particularly if changes in production necessitate changes in layout on a semi recurring basis.
WLANs are nothing if not flexible; this type of network supports communication between all manner of connected devices including, but not limited to, computers, robotics, sensors, and various other types of industrial equipment. When it comes to installation and management of a WLAN versus a wired network, there’s really no comparison. Since WLANs use less physical equipment than a wired network, the net result is a reduction in the time it takes to install the network, a lower overall cost of the network, and infrastructure that takes up less physical space.
From an operations scalability perspective, WLANs are much more amenable to expansion, as it is much easier to connect additional users and devices to the network. Management of the network itself can more or less be done remotely, as a user interface provides visibility into the health of the network, data collection, and more.
Modern Industrial Robotics Require Wireless Communications
In the early days of automation technology, industrial robotics were a game changer, but they were largely relegated to performing sedentary tasks, due in part to the wired network they were connected to. While industrial robotics could complete autonomous motion in the form of picking, placing, welding, and so much more, early industrial robotics were not quite living up to their full potential. Thanks to advancements in technology and the networks used by it, modern industrial robotics are being deployed in ways previously unheard of.
Take for example, the Automated Guided Vehicle (AGV). These autonomous vehicles are increasing in popularity across the industrial sector, particularly in automated warehouses and assembly plants where they are used for transporting raw materials and finished products. As one might expect, these activities have the autonomous robots covering large distances often tirelessly traversing the factory numerous times throughout the day. Of course, AGVs would not be possible if not for WLANs as most require on-going communications with a central control system to relay their location and load status. Imagine for a moment a fleet of AGVs connected to their network by wired tethers; not only would this be impractical, it would hinder the movement of other processes throughout the facility and create untold delays.
AGVs represent just the type of the wireless network connectivity iceberg. When less obvious devices, like proximity and analog sensors, are controlled via a wireless network it opens up a world of possibilities when it comes to solving configuration and engineering problems. For facilities that have historically used wired sensors, there is an appreciable hesitancy to replace existing infrastructure due to the cost and effort involved. Fortunately, there is a middle ground that they can use to create wireless connections. For example, some devices may connect to the existing wired sensors, receiving an analog or discrete input signal. Using a relaying adapter can effectively convert the input signal into a wireless radio frequency output, thereby modifying a traditional IO link device into IO link wireless signals.
Best Practices for Industrial Wireless Local Area Networks
There are four best practices that manufacturers can leverage in order to get the highest return on their WLAN investment. Though they may vary in importance from one site to another, each best practice should be taken into consideration.
Complete a site survey for industrial wireless. Most industrial environments are rife with potential sources of RF signal interference. This could be in the form of a nearby WLAN network, heavy machinery, ductwork, concrete walls, RFID systems and many more. With that said, it is crucial that a site survey is conducted in the prospective facility to ensure that the placement of wireless access points is optimal and there is adequate signal coverage where it will be needed. Failing to complete a site survey could result in signal to noise ratios that are not not conducive to favorable wireless communications.
Lifecycle management. Designing and installing an industrial WLAN is no easy feat, even for new builds. Oftentimes, these networks require the retention of RF engineering experts. Since the facility’s successful operation is contingent on a properly functioning WLAN, it is not advisable to attempt to set one up without the assistance of trained professionals. If engaging an outside WLAN firm, it’s important to not take their expert installation as a one and done solution. As with any piece of crucial plant infrastructure it is important to consider the lifespan of the equipment used, perform regular maintenance on it, and plan for the end of the equipment’s life cycle. Failing to do so could result in considerable downtime in the event part of the system fails and requires replacement.
Industrial wireless cybersecurity. Unfortunately, in today’s world, critical infrastructure (including those privately owned), are the unavoidable subject of cyber attacks. As we’ve seen, WLANs can be configured with numerous levels of security capable of thwarting bad actors seeking entry. Where required, additional hardware can be included to bolster the network’s security, like those providing VPN capabilities. Manufacturers considering a WLAN need to conduct a risk assessment of their operations, to expose any exploitable vulnerabilities to their systems.
IT/OT convergence. In order for the modern industrial operation to be successful, there must be synergy between the IT (information technology) and OT (operations technology) teams. Each team brings a very specific skill set that is vital to identifying the requirements of the WLAN and other networks. If the teams work in silos, and there is no cross discipline collaboration,
Industrial Wireless is Here
While traditional industrial facilities are responsible for producing many of the goods that society has come to rely upon, wireless technologies and networks allow manufacturers to more cheaply and efficiently produce these goods.
Though not the most impressive tech you’ll find in a manufacturing setting, WLANs are nonetheless a vital component to the next stage of industry 4.0.
If you’d like to learn more about modern robotics, how they work and how they communicate, consider enrolling in the Robotics Technician program at George Brown College.