DAQ software stack—TRLO II, Nurdlib, drasi...

General Information

Overview of the DAQ software stack (primarily) maintained at Experimental Subatomic Physics at Chalmers.

It consists of several components, that can be used together or individually with other systems.

Each component has its own means of distribution (typically git) and documentation. The purpose of this page is to cover some combination topics that are not naturally described along with the respective tools.

Mailing list: subexp-daq@lists.chalmers.se (archives).

Components

In rough data-flow order:

TRLO II

Flexible FPGA trigger control.

Nurdlib

NUstar ReaDout LIBrary — the definite library for readout of data collection modules commonly used in nuclear physics experiments.

r3bfuser

User readout routine.

drasi

DAQ (network) data pump — DAQosaurus parati scintilla.

ucesb

unpack & check every single bit — Bridging the gap between DAQ systems and data analysis tools.

plutt

Scriptable monitor for experimental data.

Download and building

Instructions for setting up a Nurdlib-TRLO II-r3bfuser-drasi-ucesb data chain.

Reduced instructions for a free-running Mesytec MDPP16 (SCP) with a CAEN V2718 controller and Nurdlib-drasi-ucesb.

Hardware

VME controllers

Performance

For best performance in triggered mode, do the readout in parallell with conversion, as described here: VME Readout at and Below the Conversion Time Limit.
That way, single-event readout latency is irrelevant—up to the limit of available readout bandwidth.

To evaluate the performance of any(?) DAQ system, use two counters (scalers) to determine momentary rates (e.g. as 1-second averages): requested and accepted triggers. Then plot the livetime ratio (accept/request rate) as function of reqested trigger rate. (For a free-running/trigger-less system, let the 'trigger' be any critical signal.)

Last modified: Mon Jan 15 00:17:51 CET 2024