I have used Keysight instruments in general but not that specific one, so I can't be completely sure that it will follow this model. I'm not going to go read its entire manual. I did take a quick peek at its datasheet, which says "The EL30000 Series bench DC electronic loads can continuously log voltage, current, and energy to a datafile. The sample rate is adjustable from 20 microseconds to 60 seconds. Store the data file on the internal
non-volatile RAM or save it externally on a USB memory device as a .CSV file". So I am guessing you want to gather that sort of data, which does have internal logging. You might look for certain keywords from that datasheet quote in your device manual to isolate the parts you need.
First thing to do would be to set up the instrument in general. It sounds like you kind of figured that part already, and can take individual points one by one.
Next, you'll want to find some commands that involve setting up the data collection. Probably ones that set up the frequency or period of collection, what data to collect, and when to stop and start. The stop and start might be something that can be triggered externally, or timed, or it might be something that you start and stop manually, or some combination of all that. Depending on how it's set up, you might need to also clear any previous data.
Then you'll need to send it a signal to start. Depending on how it was all set up, this will either start immediately or start looking for a trigger event.
At this point you'll need to run a command that checks the progress of the measurement so you know when the gathering is done. There is a standard SCPI command for this, "*OPC?", but you may need to check your device manual to see if it applies, as it could be that the device you have either doesn't use it, or doesn't use it in the way that you want it to (it might say it's complete when the trigger occurs, rather than when all the data is collected, for instance). You might need to find an alternate command, such as one that lists how many samples are in memory or the current state of the device (capturing vs. not capturing). Using a "Check to see if done" command instead of a "Get data" command is how you (usually) avoid timeouts.
Whenever it is done, you'll need to download it all. There ought to be a command that will often end in ":DATA?" that you use to get all the data from the RAM or file system of the device.
