Special SC readout Dears Dave, Philippe and Irakli, I was told by Reyes that end of June there will be a meeting to finalize the trigger tower definition in the endcaps. We are waiting this definition to have the final map of DCC channels. I remember that you had plans to transport in the outer tower data fibers also some inner crystal data. I would like to know if these plans are still valid. This may create a problem for data reduction. The DCC does zero suppression and selective readout, but the available FPGA resources prevents any extension of the algorithms to handle this special case. There are two solutions: - either the SRP computes flags of inner and outer towers, makes the OR of both, and sends this to the DCC (which seams complicated) - or the SRP flags always the outer towers for crystal zero suppression, independently of the tower energy content. We can not mark these towers for full readout because we would exceed the ECAL allowed data volume. Please let me know your opinion. Regards, Joao

Special SC readout Dears Dave, Ken, Irakli, Philippe, Regarding the special endcap supercrystals, I have confirmed with Irakli and Philippe that indeed the SRP may flag towers (EE supercrystals) with "forced readout" (defined by configuration). In consequent these special SC may have (for all events) full readout or zero suppression readout (depending on configuration). Irakli, Philippe, please confirm. Regards, Joao

EE Laser (and LED) readout Dears Dave, Ken, Reyes, Regarding laser events in the endcaps: - if I understand well, the laser fires the endcap per half-D Dave C – the laser fires ~one half quadrant - there is no exact matching between half-D and DCCs Dave C – correct In consequence I propose that for monitoring triggers the EE DCCs reads all channels (supercrystals). In other words, in the endcaps there is no equivalent of half-SM readout. The consequence is that the TTC DTT of endcap monitoring triggers must have the half-SM bits at 11 (all channels). Regards, Joao