About Auto-Trigger and other triggers, just to beat that (dead) Pony again.
I made a few tests on the frequency of the sweeps in Auto-Trigger mode depending on Memory depth and time base. So here is the first table, Trig frequency in relation to Mem depth and Window size. The column Sweep Time/period tells, how much of the "real" time id covered by the traces.
Mem depth Window size Trig frequency Sweep time/period
@ 100µs/div
20k 20k 805 80,5%
200k 200k 642 64,2%
2M 2M 215 21,5%
20M 2M 215 21,5%
200M 2M 215 21,5%
Next table: Trigger frequency depending on the time base setting both for standard acquisition modes and sequence mode, taken with 20k memory depth.
20k Aquiring dept
Timebase sec/div Trig freq sweep time/period Trig freq sweep time/period
Standard Acq Sequenc Acq
10E-09 22222 0,2% 303000 3,0%
100E-09 21790 2,2% 333000 33,3%
1E-06 8900 8,9% 82000 82,0%
10E-06 4329 43,3% 8700 87,0%
100E-06 805 80,5% 889 88,9%
1E-03 30,6 30,6% 89 89,0%
10E-03 8,7 87,0% 8,9 89,0%
100E-03 0,88 88,0% 0,89 89,0%
The trigger frequency was taken from the Trig Out signal and determined with a counter and PC logic analyzer. Interesting is, that the real time coverage gets pretty low for small time/div values.
What was also kind of unexpected to see was, that for low time/div rates the sweeps come in bursts with a period of about 30 ms. See the attached picture,