Improving the flexibility of the Ethernet Powerlink PollResponse Chaining mechanism

Ethernet Powerlink (EPL) is an industrial Ethernet networking solution commonly used as a communication network in distributed control and automation systems ranging from simple I/O to highly complex motion control applications. The PollResponse Chaining (PRC) mechanism is a new EPL standard feature aimed at increasing the network performance when nodes exchange small amount of data, especially if they are connected in line topology. However, the efficiency of the mechanism is affected by the network structure, which limits the scope of its applicability in real installations. In this paper, we propose a modification of the original PRC mechanism to improve its flexibility while allowing the same level of performance. This modification requires only minor changes to the available software implementation of the EPL protocol stack. The paper also presents some experimental results that prove the functionality of the proposed solution.