Rigol DS1102E trigger offset irregularity on single sweep

[AussieBruce]

Hi,  I’m trying to catch isolated events on my Rigol DSO with triggering set to Single sweep, when an event occurs there is no sign of it in the trace, even when I use the horizontal scroll knob to search from end to end. The events are around 1mS in duration, with a voltage of about 3 volts, so nothing extreme. When I adjust things so there is a continuous stream of the events, and with triggering on auto everything works fine.

My suspicion is on a field at bottom RHS of the screen in orange, “T -> 51.64mS”. I’ve hunted through the manuals, and can’t find a clear description of what this is, but I guess it might the ‘trigger offset’ briefly mentioned in the doco, if so then a delay like this could force my single shot view off the screen. Despite lots of messing with the menus I can’t see any way of changing this value. Can anyone assist? In general, the Rigol doco seems a bit patchy.

[Romualds]

1. What kind of events have to be caught? You write about 1ms duration and 3V but is it a pulse, edge (rising, falling, both), slow ramp or anything else you are looking for?
2. What are the current trigger settings?