It has segmented mode that records a number of triggered waveforms. It also has a history mode that is always running. Meaning it will remember last xxx captures automatically without need to enable anything.
From his other thread, I think his application is a 'single-shot' case (quite literally) and he wants a completely foolproof way of starting his capture.
OP: There will be a reasonable way to do what you need with any of these scopes. For example, you can set the SDS1104X-E (and presumably the SDS1202X-E) to 1s/div, trigger to 'LINE' and then press the 'SINGLE' button. The scope will start to record at 1MSa/s (one million samples per second) for 14 seconds. Once captured, you can save the waveform, zoom in on it, download it to a PC and analyze it and so forth. You can adjust all the parameters I mentioned as needed.