Multi-step Runs – an L1Calo Perspective

1. Multi-step Runs – an L1Calo Perspective Norman Gee 28-Apr-05

2. Outline – three sets of multi-step (run) requirements. Requirements • 1. Internal Timing measurements. • Use data replayed from memories inside our electronics modules • 2. Timing measurements with fixed Calorimeter pulses • A combined run where L1Calo timing changes relative to calorimeters. • 3. Energy Calibrations • Where range of calo energies are scanned and measurements made in trigger electronics (receivers + L1Calo) • General Comments C N P Gee – Installation & Commissioning

3. 1. L1Calo internal timing. • Many examples of timing scans needed in L1Calo • Most are needed to optimise capture of data sent over a link. • e.g. CPM-CPM; CPM-CMM; CMM-CMM; JEM-JEM; JEM-CMM • All our link data carry parity info. We use the parity error rate as a sensitive measure, and it’s quick. So a measurement consists of: • Load test vectors which exercise lots of bits. Then enter loop: • Set a timing value; • Clear error counters; • Wait ~1 second; • Read error counters from the modules, (as not available to RODs) insert values in Gmonitoring stream; • Iterate. • Analyse Gmonitoring stream. At end of loop, decide on best setting • Record to database. C N P Gee – Installation & Commissioning

4. Timing example – scan TTC for CPM-CPM backplane link C N P Gee – Installation & Commissioning

5. Overall architecture Root Ctrl Sequencer Crate Ctrl Analysis Module Serv. Module Serv. Module Serv. Electronics Electronics Rod Electronics C N P Gee – Installation & Commissioning

6. 2. Timing measurements with Calorimeters. • Measure the precise time and shape of calorimeter analogue pulses • Add delays to compensate for unequal pulse arrival times • Position the FADC sampling to sit at peak of calo pulse • Measure pulse shape to compute Bunch-Crossing identification coeffs. • Ensure equal timing of individual calo cells which are being summed. • Use a continuous stream of equal-amplitude calo pulses. So a measurement consists of: • Start calo pulse train, with the required raw cells enabled. • Set a timing value for the FADC sampling; • Read out 100 events from L1Calo via RODs • Iterate. • Analyse event stream (not necessarily synchronous with steps). Compute mean FADC output. At the end, determine optimum settings. • Record to database. C N P Gee – Installation & Commissioning

7. 3. Energy Calibrations with Calorimeters • Adjust analogue receivers and Preprocessor to give exact GeV ET • Final adjustment of gain vs sin  • Requires synchronised steps between calo and L1calo • Set up combined trigger, agree details of sequence to be executed • Calo sets the next analogue pulse amplitude • Calo (?) generates 100 L1As • L1Calo readout of Preprocessor ( and calo?) response via RODs. • Iterate • Analyse event stream (not necessarily synchronous with realtime steps). Compute mean observed ET per set of events. At the end, determine optimum settings taking account of detector effects. • Record to database. C N P Gee – Installation & Commissioning

8. General Comments - 1 • At present we have a first version of a multi-step run, using pause-resume transition • Much faster than starting a new run for each point • The Crate Controllers interpret the run types and do special things. • Need to understand if this will work with calorimeters. • The analysis program needs to know the step number • We insert it in the detector-specific event type. Would be nice to have somewhere better. • We have the concept of a “plan” to set up the joint runs • A database extract containing all necessary details (eg energies, no of L1As, settings for LTPs,…) for the complete run. • Avoids need for cross-communication between L1Calo and a calorimeter. • Details to be defined C N P Gee – Installation & Commissioning

9. Generall Comments - 2 • Database Issue • Electronics module settings are loaded from database • But during a calibration run they need to be changed but not preserved • Do we need any nested loops? Well unfortunately we may. • Does pulse timing stay constant with pulse amplitude? • Outer loop to change calo pulse amplitude • Inner loop to scan L1Calo timing • Do all raw cells contribute in the same way to analogue sums? • Outer loop over raw calo cell number • Inner loop over L1Calo pulse timing C N P Gee – Installation & Commissioning