Industrial plants, factories and process automation systems are increasingly deploying information and communications technologies to facilitate data sharing and analysis in integrated control networks. Despite the harsh process control environment, signal propagation loss and radio frequency (RF) interference, wireless connections provide fast and easy access to a variety of field instruments and reduce network installation costs and ongoing maintenance outlays. This serves as an incentive for the adoption of
industrial wireless networks based on industry standards such as
ISA100.11a, a wireless networking technology standard developed by the ISA (International Society of Automation) and the
WirelessHART, a wireless sensor networking technology based on the Highway Addressable Remote Transducer Protocol (known as HART). Wide-scale adoption proceeds cautiously though, as industrial environments vary widely and process control systems exhibit a multitude of critical wireless networking requirements, such as:
- Deterministic transmissions in shared wireless bandwidth.
- Low-cost operation.
- Long-term durability.
- High reliability in the harsh radio propagation environment.
Wired connections have proven themselves effective in supporting reliable, point-to-point communications between the controller and the field instruments. A problematic limitation exists with wired connections though - they are unable to accommodate the growing demands and future requirements to support adaptive network topology and rapid reconfiguration encountered in new process control systems.
In lieu of laying down miles of cables to connect hundreds of field instruments, industrial wireless communication networks provide wireless connections with customized network topology, allow for plug-and-play configuration, and offer lower installation and maintenance costs.
Compared with the requirements of standard Internet data services, wireless in the process control environment has stricter quality of service (QoS) requirements. These include more highly reliable transmissions in mobile use cases as well as centralized data analytics, tighter message latency, and lower power consumption.
