A VME: Versa Module Europa, crate controller for high speed data acquisition of heterogeneous, multi-detector systems

Modern day complex experiments in physics demand highly efficient data acquisition (DAQ) systems capable of acquiring a large number of signals with a very high resolution and near zero dead time, without compromising on the event rate handling capability. To cater to the ever growing demands of the DAQ systems, an intelligent controller with a sequencer and an in-built busy logic has been developed. The heart of the controller is a field programmable gate array that provides (a) a sequencer engine, which holds a list of read-write commands that will be executed upon receiving a valid trigger, (b) a dual port random access memory divided into two blocks of 16 kbytes, each of which is configured in a ping-pong fashion to support data acquisition and data transfer functionalities simultaneously, thereby reducing the dead time, (c) a busy logic interface that validates the master strobe or trigger, a scalar for triggers received, and a time stamp engine for time stamping the events with 10 ns interval, (d) the Versa Module Europa (VME) backplane interface for 32 bit data transfer standards of the VME, and (e) a superspeed universal serial bus communication interface to transfer the data to a computer/single board computer (SBC). The SBC is capable of booting locally or through net via a preboot execution environment from a netboot server, and it contains the driver, libraries, and data server for data collection. A throughput of 32 megabytes per second (MB/s) has been achieved with an event size of 288 signals at an event rate of 30 kiloevents per second with medium slow slave modules, which may further increase up to 45 MB/s with faster slave modules. The VME controller supports an event size (number of signals) of up to 1023 in a single VME crate. Thus, this sequencer engine based VME crate controller development facilitates collection of a high volume of data with a large number of signals at higher event rates and the least dead time; it is named as Readout Ordained Sequencer Engine.

Automated summary

To meet the demands of complex experiments in physics, an intelligent controller with a sequencer and a built-in busy logic has been developed. It uses a field programmable gate array to provide high-resolution data acquisition with zero dead time. The controller can achieve a throughput of 32 MB/s with an event size of 288 signals at an event rate of 30 kiloevents per second.