Control, mobility and data access—local or cloud—are becoming the battle cry of industrial automation. Hard to accomplish with a 2,000-ft cable attached to a laptop, yes?
Wi-Fi or wireless communication, Bluetooth and 3/4/5G cell networks can provide us with that cable replacement by allowing users to connect to systems and devices in real time to provide us with control, mobility and data access that we all need.
However, while it is easy to create that environment, there are many things to consider before and during wireless connectivity.
During one of my projects at a large warehouse, we implemented a wireless bridge system on mobile cranes, 28 of them, and tied the wireless network into the wired system. It was self-contained so no issues, right?
My laptop did not have Wi-Fi built in, so I had to get a Personal Computer Memory Card International Association (PCMCIA) card to connect to the network. While I thought I would have to get IT involved, it seemed that the implementation broadcast the wireless service set identifier (SSID) with no security—wired equivalent privacy (WEP). So, I connected to the wireless network since the mobile cranes were controlled by programmable logic controllers (PLCs), and, voila, I could connect to the PLCs and monitor the performance.
This network was available from outside the building, as well, so this is a big security issue. It was fixed promptly, but it shows how easy it is to forget a setting on a wireless router or switch/access point to allow bad actors in.
The industry has made leaps and bounds in technology for wireless communications. Typically, Bluetooth is used for device configuration, Wi-Fi for plantwide local area network (LAN) and cell technology for remote connectivity from the plant to and from the cloud.
Edge devices can have the ability to communicate to the cloud servers directly without the use of a centralized supervisory control and data acquisition (SCADA) system or data server. This configuration will still exist, but, when a specific device can do the work directly, it makes everyone’s job easier, except when things don’t work.
One really interesting issue I had was with a Wi-Fi router in a server room, which doubled as a break room. I was doing historical trending on a server over wireless, and, every once in a while, I would lose data. Packet loss is somewhat frequent over wireless, especially in the earlier days.
Well, the breakroom had a microwave. The trend data loss occurred in and around break time, but I had no idea that a microwave can operate in the same 2.4 GHz range, which is the normal Wi-Fi frequency. The router was using a fixed frequency for the wireless communication. I changed it to a spread spectrum channel configuration, and the trend data drop was eliminated. Who knew?
There have been many advancements in device wireless technology such as Zigbee for device-level communication. Valves, intelligent motor control centers (starters/overloads) and drives of all sorts can use wireless communications for data access.
Common industrial protocol (CIP) Safety can be implemented over a wireless network and can provide an application benefit for machine-level safety strategies. I have not implemented a wireless safety system, but if someone sparks up a croissant heating cycle in a microwave and an e-stop is hit but not acted upon—well, you know.
This brings us to security. Denial-of-service attacks are common over the internet. While it may not be common in a LAN environment, devices can cause interference. Third-party devices that are brought into the environment can also provide interference with the network. Data loss would occur, as well as possible control strategies being interrupted.
Wi-Fi jamming equipment is widely available and can be used to interrupt data communications. Routers and switches are single-board computers with memory and central processing unit (CPU) resources. When they are asked to process 10 messages/packets a second, they can do so with ease. When asked to do 1 million/second, they have trouble and the communication between the PLC and drive, for instance, would be blocked because the messaging would not get through reliably.
One other potential security issue is espionage from competitors. There are hackers for hire, which could infiltrate the wireless network, find assets and figure out how to install a payload to simply monitor emails or inter-departmental data for the purpose of stealing the data. They are getting smarter, and wireless gives them a larger playing field.
Password protection on the Wi-Fi network, as well as using a device list, is as important as ever. We have to assume that someone will want to break into our network. As a machine builder with the need to protect your intellectual property (IP), a protected system machine network is paramount.
As an OEM you could lose your market if someone stole your IP. As my 16-year-old bonus grandson says: “Lock it down.”
