Industrial control systems are increasingly using wireless communications to enable monitoring and control of processes that had once been economically problematic. In brown fields, distances and costs for installation often prohibit the running of new cables and conduits making wireless solutions very attractive. With costs reduced, monitoring of the physical process becomes easier and operators often desire to extend wireless to include supervisory and feedback control. Feedback control in particular requires certain reliability, latency, and performance guarantees that are difficult to characterize. Industrial wireless solutions rarely make quality of service measurements available at the control system level. When they do, the indicators such as per-link packet success rate are often difficult to translate into meaningful metrics useful to the control system designer. This is especially true for multi- hop mesh network architectures where it is difficult to translate link performance to system performance. In this paper, we propose a more useful method to characterize true network latency and reliability of a deployed industrial wireless network without need for physical layer and link layer performance metrics and design knowledge.
Journal of Research (NIST JRES) -
industrial wireless, industrial control, process control, networked control, manufacturing