Performance impact of network conditions on an IIoT system

Abstract

Advances in smart manufacturing and industry 4.0 have drawn the interest of the industry. The rise in popularity of internet of things and cyber-physical systems in a manufacturing environment meant the broader connection of devices, servers, sensors and actuators within the closed-loop control. The use of existing communication networks such as computer networks and the internet to connect controllers, sensors, and actuators introduces different communication behaviours to the typical closed-loop control. This article examines the impact of different network conditions on the performance of a control process using a remote system controller. Network conditions examined are network node location of the remote controller, latency, packet delay variance (jitter) and packet loss.An industrial plant is emulated through a system of electric motors. The emulated system uses both local controllers and a remote controller. A local controller is responsible for direct control and monitoring of a motor including failsafe features for the motor. The remote controller is responsible for control over the whole interconnected system.The performance impact of different network conditions is measured for a system with and without delay mitigations implemented. As network conditions worsen, the performance of the system degrades in a linear and sometimes quadratic fashion. The relationship between system response time and network latency is slightly quadratic, the relationship between jitter and system response time is linear, and the relationship between packet loss and system response time is quadratic.