During the data taking, monitoring the stability of the trigegr is essential. Go4-based programs as well as QA plots are illustrated and described.

To investigate and characterize the functionality of this trigger, all hardware components have been emulated with software. Methods for the analysis of the functionality of each trigger board are presented.

The most selective algorithm of the second level trigger is the identification of Cherenkov rings from electrons traversing the RICH, which alone can provide the highest event reduction factor.
Therefore the behavior of the online ring recognition has been studied in more details with the help of real and simulated data, and by comparing it to the offline analysis algorithm, providing that a good rejection of misidentified rings, which have is guaranteed with the selection of a lepton candidate sample.