Yokogawa's DLM2000 and DLM4000 mixed-signal oscilloscopes have been enhanced with longer memory options.
Fundamentally, larger memories offer two advantages. The first obvious point is that more memory allows a longer acquisition time. The second is that, for the same acquisition time, using a larger memory can result in a higher sample rate - which actually means that the effective bandwidth of the measurement is increased.
There is yet a third benefit of a larger memory, which comes into play if the whole memory is not required for a particular measurement. For example, if the oscilloscope is equipped with a one megapoint memory and the instrument is set to use 100k points, theoretically it could capture ten acquisitions before the memory needs to be overwritten. This is the basis of the "history memory" used in Yokogawa oscilloscopes. If the history memory capability is combined with a fast waveform acquisition rate, it becomes possible to capture occasional anomalies and analyse them without having to rearm and retrigger the DSO. The search features can be used to isolate individual waveform acquisitions, which means that not only can the anomaly be analysed on its own channel waveform but the other input channels can also be analysed to help identify the cause of the anomaly. Using this approach, Yokogawa is able to offer MSOs with two, four and eight channels.