Dynamic priority based arbitration mechanism for CAN Network using master node.

A. F.  Murtaza; Z. A.  Khan

Controller Area Network (CAN) is a multi-master message broadcast system widely used in embedded and industrial applications. CAN works on a fixed priority based arbitration mechanism due to which sometimes its message scheduling become controversial due to its limitation like higher priority messages do not allow low priority messages to appear on a CAN network thus creating a starvation for these low priority messages. As in a CAN network there is nothing special which will address these critical situations so possibly a general failure in the communication may occur as all the nodes are not perfectly contributing in the communication. This paper addresses this issue and introduces a Master node in a CAN network which will continuously scan the whole network and does not do anything extravagant as far as all nodes are contributing their respective messages in the communication. But when some nodes are not contributing in the communication then this Master node start producing messages for these low priority nodes in such a way that these struggling nodes after receiving a message from master node increase their priority to such that they can easily appear on a CAN network which they cannot do before in normal CAN network and continuously fighting with the higher priority messages. Therefore, all the nodes are blessed with this extra ability due to Master node that they can change their priorities thus making a CAN network which can work on a dynamic priority based arbitration mechanism resulting starvation free CAN network. The whole idea is applied on a hardware and results are recorded using a CAN king software version 4.0.