Hi A-Rod, you are right: we usually need a loop in this situation. A cumulative sum is usually done with a "memory" block like this:
I am using the 8 values you provided as an example.
I have seen other solutions such as using a "unit delay" block, integrator blocks, and the dedicated "Cumulative sum" block from the DSP System Toolbox.
I recommend paying attention to the time. When should the cumulative sum be performed? I changed my solver settings to take discrete steps at 1 second. Be careful to not run into issues where you are summing the same value more than once.
