Ethernet network-based DAQ and smart sensors for the OPERA long-baseline neutrino experiment

We propose a data acquisition scheme for the OPERA long-baseline neutrino experiment based exclusively on Ethernet. The expected data rate allows the use of an Ethernet capable device close to the sensor. The basic idea is to build a distributed acquisition system on Ethernet, made of about 1000 nodes of 64 channel front-end modules. Each node will be controlled and readout by an embedded Ethernet chip and will be therefore transparently visible on the network. These modules will be directly controlled by the event building computers and will be able to execute a set of embedded functions for slow control monitoring and data readout. We present a first prototype of Ethernet capable front-end module with high speed ADC and TDC capabilities. A custom ASIC from Agilent Laboratories has been used. This device includes an embedded web server and implements the IEEE 1451.2 standard. This paper presents a full hardware implementation of a Smart Interface Transducer Module (STIM) defined by the IEEE 1451.2 standard. We describe a STIM architecture dedicated to the front-end control and readout, designed in VHDL and synthesized in a FPGA. We present preliminary results and functional validation of the control and readout functions through Ethernet and simple web browser tools.