Hello,
I am not sure about the CSV_WRiter error. It implies you have changed something w.r.t the data structures being written to CSV.
If IN GENERAL your goal is to have the 3rd pump on at some rate during an experiment, what I would do is add it to the main runExperiment function. It will need to turn the pump on again every loop (i.e. put this around the line “LightActuation(M,1)”, so that the pumping happens after measurement. Otherwise, the problem may be that you are indeed turning the pump on manually with the GUI but given the automated experiment is running it will turn it OFF again every loop since it wants all pumping to be disabled to do measurements… Hope this makes sense!