Why time-sensitive networking is critical in IIoT

The Industrial Internet of Things, also known as IIoT or Industry 4.0, is all about connected devices transmitting data that helps plant and factory operators become more efficient and productive. Against this backdrop, ensuring that data is transmitted in a timely and reliable manner becomes critical. This is where time-sensitive networking (TSN) can come in handy.
 
That’s the point raised by John Wu, Field Marketing Team Leader for Taiwan at National Instruments, in a technology seminar held on January 8 in Taipei, discussing artificial intelligence and blockchain.
 
At the heart of TSN is synchronization of devices in a system. Wu cited an audio system as a simple example, whereby the microphone and speakers are all in sync, in order to avoid feedback or other noises that can damage the audio experience.
 
Time-sensitive networking is a set of IEEE 802 Ethernet sub-standards that are defined by the IEEE TSN task group. According to IEEE, TSN is the foundation to provide connectivity to time and mission critical industrial applications on converged networks of operations technology and information technology. “TSN meets these requirements by providing interoperability via open standards. TSN provides synchronization and supports real-time control over a single standard Ethernet network,” the organization said.
 
“TSN provides guaranteed data transport with bounded low latency, low jitter and extremely low data loss. TSN includes multiple solutions to provide bounded low latency, for example time-scheduling, preemption and multiple shaping mechanisms. Ultimately, TSN provides zero congestion loss. Time synchronization and TSN QoS solutions reduce jitter associated with control packet delivery to upper layers, for example in controllers and actuators,” IEEE said, adding that security is another important element. “Authentication of installed devices (secure device identity), segregation of traffic types and flows between authorized devices, message integrity, and authenticity are possible.”
 

Benefits for manufacturers

 
This is critical in a manufacturing or factory setting where data is transmitted between devices in various systems, for example machine vision, robotics and automated guided vehicles, Wu said.
 
According to Wu, time-sensitive networking has three major components. “These are time synchronization, which ensures that end nodes and switches have a common understanding of time; traffic scheduling, which ensures that packet transmission from a sender to a receiver is scheduled end to end and follows a repeating cycle; and system configuration, which ensures that a consistent mechanism for network configuration helps meet application needs,” he said.
 
When these are combined, benefits to manufacturers are manifold, as interoperability is assured between all devices residing on the same Ethernet network, bandwidth management is optimized, and data security is further enhanced, he said.
 
Wu meanwhile mentioned various NI products and solutions enabled with time-sensitive networking capabilities. These include the CompactDAQ Chassis, which can include multiple general-purpose counters/timers that one can access through an installed, hardware-timed digital C Series module for applications that involve quadrature encoders, PWM, event counting, pulse train generation, and period or frequency measurement; the CompactRIO controller that combines a processor running NI Linux Real-Time, a programmable FPGA, and modular I/O with vision, motion, and display capabilities, ideal for applications that need high-speed control or signal processing, hardware algorithm acceleration, hardware reliable tasks, or unique timing and triggering; and the industrial controller that creates a complete vision system, explore other vision system components, such as lighting, lenses, and cables.