The CMS Regional Calorimeter Trigger (RCT) receives eight-bit energies and a data quality bit from the HCAL and ECAL Trigger Primitive Generators (TPGs). The RCT uses these trigger primitives to find e/γ candidates and calculate regional calorimeter sums that are sent to the Global Calorimeter Trigger (GCT) for sorting and further processing. The RCT hardware consists of one clock distribution crate and 18 double-sided crates containing custom boards, ASICs, and backplanes. The RCT electronics have been completely installed since 2007. The RCT has been integrated into the CMS Level-1 Trigger chain. Regular runs, triggering on cosmic rays, prepare the CMS detector for the restart of the LHC. During this running, the RCT control is handled centrally by CMS Run Control and Monitor System communicating with the Trigger Supervisor. Online Data Quality Monitoring (DQM) evaluates the performance of the RCT during these runs. Offline DQM allows more detailed studies, including trigger efficiencies. These and other results from cosmicray data taking with the RCT will be presented
