The time resolution for the system is 30.512 
sec for event
characterization (SEC, ESM, WCM), and 12.21 sec for time
interval (TIM) spectra. The maximum continuous count rate is
5000-10000 cts/s, which limit is determined by the capacity of the
DPUs with the actual load by various software tasks. The upper limit
is close to 2 Crabs (one Crab is about 3500 cts/s with SIXA).
The analog electronics part of the system can separate events with a much higher time resolution than indicated above, which property is used by hardware for coincidence and pile-up rejection. X-ray bursts caused by, for example, cosmic radiation hitting the satellite will thus be filtered out effectively before they enter the digital counters. Direct hits of high energy cosmic rays will also be rejected because they exceed the energy range of SIXA.
The dead time correction for SIXA countrates can be estimated from the total countrates in the 3 subgroups of detector pixels (see Figure 57), using a time constant of 12.21 microsec for the TIM mode, and 30.512 microsec for all the other modes. For a 300 cps/group source the dead time correction would be about 1%, and for a 3000 cps/group source about 10%. The pile-up effect (signal of two or more events combined into one detected event) is significant only for very large countrates (about 10000 cps or more).