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

Outline – three sets of multi-step (run) 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 28 April 2005 C N P Gee – Installation & Commissioning

C N P Gee – Installation & Commissioning 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. 28 April 2005 C N P Gee – Installation & Commissioning

Timing example – scan TTC for CPM-CPM backplane link 28 April 2005 C N P Gee – Installation & Commissioning

C N P Gee – Installation & Commissioning Overall architecture Sequencer Root Ctrl Crate Ctrl Analysis Module Serv. Module Serv. Module Serv. Electronics Electronics Rod Electronics 28 April 2005 C N P Gee – Installation & Commissioning

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. 28 April 2005 C N P Gee – Installation & Commissioning

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. 28 April 2005 C N P Gee – Installation & Commissioning

C N P Gee – Installation & Commissioning 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 28 April 2005 C N P Gee – Installation & Commissioning

C N P Gee – Installation & Commissioning 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 28 April 2005 C N P Gee – Installation & Commissioning