DEVICE LEVEL BUSSES AND DEVICE LEVEL NETWORKS IN WATER AND WASTEWATER FACILITIES

A Water or Wastewater treatment operation's efficiency is rigorously constrained by its ability to effectively communicate with its associated field equipment and instrumentation. This communication manifests itself in both analog process data from field instrumentation and digital status data from field equipment and instrumentation. Control systems installed in treatment plants require communications to each device to retrieve the data for control, alarming, reporting, and presentation to the user. Communications have traditionally consisted of 4-20 mA analog data or contact closure discrete data to the control system modules. The common approach used to physically connect the various components of a traditional system utilized the “spider” method where one cable pair is wired to each device and piece of equipment.