The Istep object encapsulates information about the initial and final currents, the elapsed times at each current, and the data-acquisition rate. Most of the activity associated with the Istep happens in the background while a Ciiv.Run() is being executed.
The current range used for the ISTEP signal-generator is selected from the larger absolute current in the waveform. The current range is fixed throughout the scan. The program does the best it can to reach the lower current using the current range in use. Generally the smaller current is only imprecise if it differs from the first by several orders of magnitude.
If the Skip button is "pressed" during the initial phase of the run, the Istep signal generator advances to the final phase. If the Skip button is pressed during the final phase, the Ciiv.Run() is prematurely ended.