Wireless telemetry is often perceived as simply connecting remote assets to a network and transmitting data back to a control room. In practice, bandwidth, terrain, line of sight, power availability, network traffic and environmental conditions all influence performance.
One of the biggest misconceptions surrounding wireless telemetry is that modern digital radio networks behave like conventional wired Ethernet systems. While the technology has evolved significantly from the analogue radio systems used in earlier telemetry applications, the fundamental challenge of managing wireless traffic remains.
Early telemetry systems relied on analogue radios using techniques such as frequency shift keying (FSK) to transmit data. Modern systems use digital communications via RS232, RS485 or Ethernet interfaces. However, unlike a wired network, only one wireless device can successfully communicate on a frequency at any given time. If multiple devices transmit simultaneously, collisions corrupt the data.
Effective wireless telemetry relies on disciplined network management. Rather than continuously polling every remote node, modern systems increasingly use “report by exception”, where devices only transmit when a change or event occurs. Multi-point systems using carrier sense multiple access (CSMA) allow nodes to listen to network traffic and wait for a gap before transmitting. This reduces unnecessary traffic and improves network efficiency.
Standards such as ISA100 Wireless and WirelessHART were developed to improve wireless reliability and determinism in automation. For Omniflex, ‘managed wireless’ has long been central to telemetry system design. Omniflex developed its own radio protocols (Conet m) using experience gained from original radio techniques such as MSK and FSK, adapting them to the digital radio environment where managed wireless is essential for maximum performance.
The practical challenges of telemetry
Designing telemetry systems for remote environments also introduces physical challenges often underestimated during system planning. Terrain, line-of-sight limitations and environmental exposure can all impact reliability, particularly where monitoring points are geographically dispersed. In many applications, telemetry equipment must operate in locations exposed to high temperatures, heavy rain, dust and vibration, making rugged product design and high IP-rated enclosures essential.
Power availability is another major consideration. Many remote telemetry sites lack reliable mains power, meaning systems must operate using batteries and/or solar power. In battery-powered applications, reducing transmission frequency is critical to extending operational life, with some systems configured to wake periodically, transmit data and return to a low-power sleep state.
Scalability becomes more important as telemetry networks expand. While cellular infrastructure can support large numbers of connected devices, licence-free radio systems require careful management of bandwidth and network traffic. As devices are added, network efficiency can quickly degrade if communications are not properly controlled. Peer-to-peer networking and managed wireless protocols help reduce unnecessary traffic and improve responsiveness.
Omniflex’s experience developing industrial networking technologies has reinforced the importance of designing telemetry systems around openness and efficiency rather than unnecessary complexity.
The focus on simplicity also influences how telemetry data is visualised and managed. Traditionally, telemetry systems relied on large SCADA platforms for monitoring and control. However, engineers are increasingly moving towards focused touchscreen HMIs that reduce maintenance overheads, software management and cybersecurity risks associated with PC-based SCADA. Simpler architectures are often easier to deploy, maintain and operate.
Ultimately, one of the biggest lessons from long-distance telemetry deployment is that reliability is rarely achieved through complexity alone. Careful network management, efficient communication protocols, rugged system design and open architectures are critical to long-term performance.
Authored by Ian Loudon, International Sales and Marketing Manager at Omniflex
