Monitoring wireless industrial LANs in the factory of the future: importance and strategies

This article originally appeared in the April'23 magazine issue of Electronic Specifier Design – see ES's Magazine Archives for more featured publications.

While Bluetooth or 5G are often perceived as the best wireless technologies for data transfer, they may not always be the optimal solution. As a result, we are witnessing a growing adoption of industrial wireless LAN, but what is it, and what role does it play in the rise of the smart factory? Martin Hodgson, Regional Manager, Northern Europe, Paessler AG further explores.

The advantages of industrial wireless LANs

An industrial wireless LAN is similar to the WLANs found in the corporate and private worlds. It is based on one of the IEEE 802.11 standards and is compatible with wired Ethernet. Its strengths lie in its ability to cope with the specific demands of the factory floor.

The biggest differentiator for this technology in industrial environments is that networking equipment has to be rugged and more robust to handle the extreme conditions of a typical factory floor. For example, devices need to withstand very high or low temperatures, high humidity levels, constant dust, or excessive vibrations. The very nature of factory floors means specialised Wi-Fi solutions are needed. For example, radio frequency interference and masses of large metallic surfaces mean that better radio frequency management and stronger wireless signals are a must.

Incorporating wireless connectivity in a factory brings about many opportunities, but one of the biggest is the ability to connect mobile endpoints. This covers a range of applications, from giving technicians the possibility to access production data on their mobile phones or tablets, through to enabling communication with moving machine parts.

Monitoring connectivity of industrial wireless LANs – a guide

Wireless network reliability is far more critical in industrial settings than in corporate environments, especially if process and safety controls are executed using the wireless network. In this case, even a short downtime can result in a halt in production, poor quality output, or other negative outcomes.

The latest wireless LAN standards offer features that improve efficiency and reliability of wireless signals (such as MIMO in 802.11n or OFDMA and MU-MIMO in 802.11ax); but despite this, monitoring the status of wireless connections and the supporting infrastructure is crucial. Here are three tips for getting started with monitoring your industrial wireless LAN.

Keeping track of the devices in the wireless network

This includes the routers, access points, switches, and other network equipment. Many network devices offer SNMP functionality or a REST API (or both) where status information can be obtained, and this information can be used to get alerted when the hardware has failed.

Another option is to utilise the tools provided by the networking devices themselves. Many manufacturers include built-in tools that can keep you updated as to the status of the equipment. For example: Moxa, a provider of industrial wireless routers and other devices, also offers a tool that lets you monitor the wireless connections of their devices as well as changes in those connections that might be of interest.

Keeping an eye on connected devices on the network

Another good strategy to monitor the health of a wireless network is to check if the connected devices are reachable. A simple ping here can suffice. A device that does not respond to a ping might have malfunctioned, but it could also be that the wireless network has gone down.

A company by the name of, STIEBEL ELTRON, for example, uses automated guided vehicles (AGVs) at its production site. These AGVs are autonomous in that they receive their orders over Wi-Fi at various checkpoints. If the wireless network is down, the AGVs do not get orders and they stop – resulting in downtime and a delay in certain processes. 

STIEBEL ELTRON’s IT service provider, Bechtle, indirectly observes the wireless network by monitoring the AGVs with Paessler PRTG which regularly pings each AGV, and if an AGV is not reachable, an alert is generated. This way, admins and technicians can immediately check if the network and each AGV is functioning as they should.

Centralise data monitoring

This is more of a general monitoring best practice tip than it is specifically about wireless networks. Consolidating all of your monitoring data in one tool is the best way to give you centralised dashboards and alerting for the most holistic picture. This includes having data from all your locations, from your OT environment, from your IIoT sensors, from your wired and wireless networks, and from your traditional IT devices and systems in one location.

As the smart factory gains momentum, significant changes have occurred in recent years. Establishing a robust and dependable network connection lays a strong foundation and safeguards manufacturers from stumbling at the outset.