chart recorder instead of xy recorder: monitoring instruments in experiments w/o preset duration?

[nfortune]

I would like to use QCODES to monitor cool downs of probes inserted into cryostats--- more specifically, a series of simultaneous measurements of resistances of multiple sensors from a set of instruments --- but I am unsure how to run an experiment that has an unknown end time. I understand that measurements can be made as a function of time instead of a function of magnetic field (as in measurement of resistance while sweeping an applied magnetic field) or temperature but in a cool down, it doesn't always take the same amount of time to reach base temperature, and the temperature isn't actually a variable under my control (until cold). I would like to have QCODES collect data until I tell it to stop --- or even better , click pause, then pause till I click resume, then continue till I click stop --- using a keyboard interrupt. Is there a reasonable way to do this besides specify a 48 hour collection time and then use a keyboard interrupt to halt collection? Or is that the reasonable way? I worry there will there be an inordinate number of empty values in an overly large data set if it only takes 14 hours for some probes and 36 for others (if cryostat starts warm)? Can the data collection be paused and resumed? Essentially I am looking to see if QCODES can be used as an old fashioned chart recorder or never ending seismograph rather than an an old fashioned x-y recorder with a well defined start and stop parameter. Alternatively, I am looking for a way to say, "collect data until you reach a certain temperature" even if I don't have a way to control the temperature sweep rate.