New communication network protocol for a data acquisition system

Event builder based on a communication network (e.g. IEEE 802.3 (Ethernet), asynchronous transfer mode (ATM), etc.) has been used in high energy physics experiments. Ethernet with the TCP/IP protocol suite is widely used because its infrastructure is very cost effective. However, in the case of event builder, each event fragment is heading for the same destination at the same time so that data flow control is required to avoid congestion. It is difficult to achieve the good transfer efficiency within the TCP/IP protocol suite. In order to solve this problem, we have developed a simple network protocol encapsulated in Ethernet frame. The protocol is designed to keep the sequence of senders so that no congestion occurs. We have implemented the protocol on a small hardware device (field programmable gate array (FPGA)) and measured the performances so that it will be ready for the general data acquisition (DAQ) system.