On the Characteristic Features of Implementing the NET Linx Open Network Architecture in the Control Logix System

The article describes the characteristic features of implementing the NET Linx open network architecture in the Control Logix system. We analyzed how the main types of networks in this communication protocol architecture work in the standard three-tier model of an industrial enterprise’s supervisory control and data acquisition system. We used the 1756-A4 chassis-based Control Logix 1756 platform with the 1756-ENBT, 1756-CNB, 1756-DNB Series C switching modules and the 1756-L55 processor as a study and analysis model. This configuration allows transferring data using the Ethernet IP, Control Net, and Device Net protocols belonging to the operating control, automatic control, and input/output tiers, respectively. End-to-end information transfer from the automatic control tier to the input/output tier as well as the characteristic features of data transformation upon transfer from one tier to another, the impact of these transformations on the data transfer delay time and the bandwidth are of major scientific interest. The latter parameters were given special attention, because the system’s response time and delay stability are the key parameters of operation of the supervisory control and data acquisition system on the whole.