L Camacho(LC), M Cattaneo(MC), J P Dufey(JD), Y Ermoline(YE), F Harris(FH), J Harvey(JH), B Jost(BJ), P Mato(PM), I Mandjavidze(IM), H Muller(HM)
1) Discussion on project organisation ----------------------------------
FH proposed that in the context of having to produce material for the Technical Proposal(TP) that we should produce 3 documents for the data acquisition system
. User Requirements Document (URD) . Functional Model Document (FMD) . Implementation Model Document (IMD)
A draft skeleton of the URD had already been circulated to a few in DAQ group for comment.(see next item on the agenda)
It was agreed to produce these documents, each of which would require a substantial amount of work which would be shared amongst the DAQ group using a project plan for task allocation. There would be regular meetings each 2 weeks, open to all in LHCB. Minutes would be produced and put on WWW to enable the whole collaboration to follow progress.
2) DAQ URD - discussion on its structure and future development ------------------------------------------------------------
FH outlined the structure of the document which had the point of view that the users of DAQ were
It was agreed to pursue the first 7 items as a matter of priority for the TP. The following agreed to pursue the user requirements for the following areas and report at the next meeting on April 29.
. Detector Readout F Harris . Level-0 and Level-1 P Mato . Level-2 and Level-3 J P Dufey and F Harris . TTC Y Ermoline and B Jost . Slow Control P Mato
JH agreed to work with FH to put document in official Framemaker template.
It was intended to put a version of the URD on WWW soon after the next meeting on April 29.
3) Status of SIMDAQ-C++ evaluation -------------------------------
LC has spent the past 3 months evaluating a tool developed by J Vermeulen (Nikhef) for modelling of the Atlas 2nd level trigger. This has been done with a view to adapting it for use in modelling the LHCB DAQ/Trigger system.
A simple problem has been implemented, involving the modelling of of trigger generator producing events flowing through 2 processors and a buffer.
The first conclusions were that some basic constructs in SIMDAQ can be used. However it is not trivial to adapt the existing objects, and the documentation is currently rather limited.
It was agreed to pursue this evaluation. Jos Vermeulen is being very helpful as a consultant when problems arise.
4) Proposal for LHCB Trigger/DAQ network assessments -------------------------------------------------
JD and IM proposed an approach for modelling network contention in the LHCB framework. In the general LHC context laboratory measurements would soon exist for the 'sources' i.e. the level-2 buffers, and the 'destinations', the processors. They proposed a first modelling without worrying about the processing in the destinations, but rather varying level-1 and level-2 trigger rates, level-2 and level-3 data and the destination assignments.
There was lively discussion as to how meaningful such a model could be without information on the processing and the application protocols. It was agreed to continue this discussion and have a presntation at either the next meeting or the one following.
5) LHCB use of TTC ---------------
YE had produced for Bruce Taylor a short summary of the possible use of the RD12 TTC system. BJ commented that we should add comments reflecting our worries about some limitations
. The 1 MHz level-0 rate places a heavy load on the bandwidth of the TTC. It could only work if we keep evnts in order at level-1
. There is concern that having written information to TTC registers one cannot read back over the same communication channel to check successful reception
YE and BJ agreed to produce modifications of the short note to reflect our concerns
6) AOB ---
We had been invited to produce a paper for Real Time 97 (RT97) at Beaune in September. It was agreed not to produce a paper, since all our efforts should go into the work for the TP. However we should attend some of the relevant topical sessions.
7) Actions from this meeting ------------------------- . Produce detailed project Plan (FH et al) . Pursue URD sections as under 2 above . Continue evaluation of SIMDAQ C++ . Continue discussion on and definition of a first LHCB DAQ model . Look at use of Foresight for modelling (HM) . Complete LHCB summary on TTC for B Taylor
8) Next meeting and agenda -----------------------
Tuesday, 1030, April 29, 32-sc-22
. The Project Plan (FH et al)
. Report on DAQ URD areas (from individuals responsible) detector readout, triggers, TTC, slow control
. Status of discussion on the first LHCB DAQ model (JPD et al)
. AOB