Outstanding Issues

• Should central rack be left for RODs etc? Latency could be slightly reduced; but no space for future trigger improvements (or problems).
• My diagrams have JEM crates closer to CTP than CPMs. If Jet/Et system in fact has the shortest latency this should be reversed.
• EM Barrel/Endcap summing is easiest if Barrel and Endcap receivers for one side (A or C) are in the same rack - if Calo grounding etc permits.
• Most significant effect comes from decision on routing of the cables between Receiver modules and the PPMs. Do these need to be the same stiff bulky cables as those from the detectors? (NB cable splicing required?) Probably 10cm*10cm from each crate.
• Central racks have limited space in front... Since the cables will now be laid through the shielding wall without connectors, we may not need all three holes. Maybe shift trigger racks to one side (reversing previous request to ATLAS technical coordination!). This would also put the calo trigger above the CTP.
• Aside: since Muon RPC trigger has lowest latency, it seems more sensible (for the latency) if the CTP, MuCTPI and TTC systems were more central.
• Timescales: changes within the calo trigger system dont have much effect and can be left till later. But calorimeter signal cable lengths need to be determined earlier? When? If USA15 end connectors are installed in situ, can this decision be left till much later? Last date for changing rack layout in USA15?.