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The Bordeaux Data Acquisition system. http://ftp.cenbg.in2p3.fr/astropart/Smith/BordeauxDAQnote.pdf Brief history Acquisition computers (VME!) harmonized with User, etc computers Separate topic: the mobilnet . Conclusions. History. It all started with the CAT Cherenkov telescope…
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The Bordeaux Data Acquisition system • http://ftp.cenbg.in2p3.fr/astropart/Smith/BordeauxDAQnote.pdf • Brief history • Acquisition computers (VME!) harmonized with User, etc computers • Separate topic: the mobilnet. • Conclusions
History • It all started with the CAT Cherenkov telescope… • VME detector readout, including GPS and scalers, by U. Paris • Choice of Motorola 64080 based MVME 164 crate controller • « Industry Pack » daughter card to handle event interuppts • Lynx OS (real-time unix-like, now called Lynuxworks) • HP workstation for “Master Run Controller” was in LabView!, by E. Polytechnique • “rsh” between multiple computers, binary packets zip across ethernet (commands & data) • …then there was CELESTE… • “Master Run Controller” ported to linux PCs. • Explosion in number of 2ndary acquisition and display computers, and in data volume. Robust, modular, expandable architecture. • …and finally the GLAST testbeams. • mini-CAL to Ganil, CERN, and GSI in 2003 • significant re-write: GlastAcq and GlastView in C++ and ROOT. • even more modular
Trigger interrupts, and data formats The CIO32 is an “Industry Pack” daughter card. We have another one for RS-232 serial connections, if you like.
Speed • In CELESTE, we typically read 20 bunches of 128 bytes each from ten VME cards from 3 VME crates in under 10 ms. • That is, 20*128b/10 ms = 256 kb/s • Triggering 256 kb events at 20 Hz gave us 20Hz*0.01=20% deadtime. • At CERN 2003, we had • ~ 7*32*1.5b*400 Hz = 134 kb/s • (we could have gone faster…) At GSI, CAL EM set the readout cadence, with Bordeaux DAQ following. Above means “better than 1 per 700 msec”.
Modular Software architecture If you add a new VME card to the system, you have to write a new routine here (Little text files describing current setup) Names of some CAEN VME modules we’ve used.
Mobilnet (1 of 2) Problem: folks show up with computers at the darnedest times, and the computer division isn’t necessarily ready to register their MAC numbers. Solution: a dedicated PC+router, housed in a 19-inch 3U rack box, with 7 output ports. Local administrators only see one MAC number… At CERN 2003, we plugged a switch into it and had our own little Internet Café of folks looking at data on their laptops. 40 connections is easy, more could be done.
Conclusions • We have a tried & true VME-based data acquisition system with a comfortable protocol for data & command exchange with remote computers, e.g. “run control console”. • On the remote computers, we have a ROOT event display and online monitor, all in C++. • We have an ADC and some discriminator+scaler pairs. • Some development necessary once specific needs defined. • Let’s talk about testbeam needs for ancillary DAQ… • We’ll bring the “mobilnet” to ease network access.