ThingSpeak

You have a lot of options. Much of how you choose to plot it depends on your timestamps. In this example for temperature for three different days , I had to do some extra work to play the different time stamps on the same x axis. If all the time stamps are the same or at least in a similar range, you can more easily plot them all by calling hold; after the first plot command, and then call successive plot commands for each plot you want to add. You can also use the tiled layout to stack plots, but for 50 machines, the plots would be come very tiny. Since MATLAB has a lot of computational power built in, I would recommend you develop a custom plot type. Perhaps calculate the mean of all 50 machines and then only plot a machine if it is within some standard deviations of the mean, for example. Good luck, please share your final plot if you can.