ATLAS
Level-1
Trigger:
CTP and TTC
ATLAS Home Page
CTP and TTC
The Central Trigger Processor (CTP) receives trigger information from the calorimeter and muon trigger processors, as well as from other sources of trigger. It generates the Level-1 Accept (L1A) based on a trigger menu.
The Local Trigger Processor (LTP) receives timing and trigger signals from the CTP and provides them to the TTC system. Alternatively, it can generate timing and trigger signals from a pattern generator or from local inputs.
The Timing, Trigger and Control (TTC) system distributes the Level-1 Accept together with the LHC clock, other trigger information, and control commands to the detector frontend electronics.
The Readout Driver Busy Tree (BUSY) is a hierarchically-structured fast-feedback network which receives the BUSY signal from the detector's RODs and sends it to the CTP.
The LTP, TTC and BUSY of the ATLAS experiment can be partitioned. Each TTC Partiton consists of:
- one LTP,
- a TTC system (one TTCvi, and TTCex/TTCtx/TTCvx, TTCoc, TTCrx, etc.),
- a BUSY tree (one or more ROD_BUSY modules).
The TTC partition is controlled by the LTP and the TTCvi, and can be run with the common timing and trigger signals from the CTP, or stand-alone with local timing and trigger signals.
Configuration, Control and Monitoring of the CTP is provided by the CTP Controller which reads the trigger menu from the configuration database, see [ref.]. The LTPs, TTCvis and ROD_BUSY modules of the TTC partitions are configured, controlled and monitored by partition controllers whose skeletons and low-level libraries are provided with ROD Crate DAQ, see [ref.].
A list of people involved in the Level-1 CTP, LTP and TTC can be found here.
Back to level-1 home page
Last updated 11 April 2006 by Ralf Spiwoks