Take the fear out of going wireless by using a stepwise approach

Plant owners adhere to many technology policies that are now decades old. Owners can re-examine these policies and consider new wireless technologies to capitalize on the data that’s available to make operations safer, more efficient, and more profitable for machine builders and operators. 

For example, Bluetooth sensors could be connected to a point-to-multipoint radio system to wirelessly monitor temperature, humidity, and more. A plant manager could use a radio data link to an overhead crane to replace any worrisome section of cable, such as long trailing, festoon cables. 

More than a few managers hear the word “wireless” and think about running a factory automation process only to have a link break and see all (or a significant part of) their factories go down. But there are many ways to approach wireless in a factory setting. With that in mind, I recommend that you try wireless in a few places and build on the successes. Consider a stepwise approach to put wireless safely and reliably into a plant.

Step one: Connect a wireless sensor

Connect a device or machine to a wireless sensor that won’t derail a process if something were to interrupt the wireless communications. Bluetooth 5.0, with its improved range and spread spectrum technology, is ideally suited to noisy factory environments. With such a system in place, the manager might attach a sensor to a piece of equipment like a motor or pump, something that ordinarily doesn’t have a lot of environmental sensors. A setup like this could capture data that signals when maintenance is necessary or even predict failure. The sensors would be industrial-strength products meant for an environment that’s dusty or exposed to washdown. The sensor data could be tapped without using the factory control system, but with some sensor systems, it is even possible to bring the sensor data into the factory’s PLC or SCADA system. 

Step two: Cut the cable

In places where control system cabling is subject to failure, (e.g., rotating equipment or overhead cranes), it’s possible to establish point-to-point reliable and secure radio links. With a base station connected to the control system, and a radio system mounted to an overhead crane’s trolley, a plant owner can create a Bluetooth link to replace the cable. Whether for a crane or other machine, some wireless systems are now so reliable that they can even be used to transmit a safety protocol like PROFIsafe between a safety controller and field devices. And PROFIsafe has no effect on the standard bus protocols used, whether with industrial Ethernet (i.e., PROFINET IO) or PROFIBUS-DP. The radio link behaves like a cable.

Step three: Bridging IT and OT

It’s not unusual to see a kind of moat between IT and OT, so a step toward widespread use of wireless would be bridging the IT-OT gap and getting data off the factory floor, in a secure way. Manufacturers like Tesla embrace unlocking and securely disseminating data. With Industry 4.0 (i.e., using technology to automate, monitor, and analyze supply chains), linking the world of OT and IT is more important than ever. 

There’s a growing acceptance among plant managers for using wireless technologies, in the form of gateways, that use wireless to move factory data securely across the OT/IT divide using protocols such as MQTT or OPC-UA, a platform-independent standard enabling the secure sharing of information from industrial systems. OPC-UA, or the open platform communication unified architecture, has been around since 2008. 

Step four: Let the outside world in, temporarily

Picture wirelessly accessing a plant floor via a cellular connection to an IT-secure tunnel. With a remote access router, a plant manager could pull data from the factory floor for IIoT applications. And machine makers could remotely connect to equipment on the plant floor to troubleshoot, load firmware updates, or change configurations without having to roll a truck for a service call. 

As for security, there are IoT routers designed for industrial environments that can allow the plant personnel to grant remote access by physically rotating a key to allow (or turn off) access to connected machines from the outside world. These routers use “data diode” technology, which is capable of physically disconnecting the “wiring” between the OT side of the router and the wireless or cellular side of the router. The key has three positions:

• Turn off communication in both directions.
• Enable one-way communication to send data out to a cloud application.
• Open two-way communication for troubleshooting and software updates from an OEM.

Secure and multifaceted wireless

Hesitancy about the use of wireless technology stems in part from a desire to control access, and from a lack of familiarity about the many uses for wireless technologies. Manufacturing and automation professionals are also slower to adopt technology because (to their credit) they’re hypervigilant about keeping bad actors out of their systems and facilities. 

But to view wireless technology as monolithic undercuts how it has evolved to be multifaceted and secure. For instance, security on a wireless link is no different than on Ethernet. You can prevent someone from joining a Wi-Fi network simply by hiding the SSID. Finding the network without the SSID is a considerable challenge and breaking in would require a determined effort with heavy-duty tools, which could even happen through a wired connection.

Plant and facility managers owe it to themselves to audit their technology protocols and review their policies for the factory floor. There’s much to be gained from unlocking data about, for instance, machine performance. The switch to wireless needn’t happen all it once. The move can be one step at a time.