The current is ramped from an initial current to an apex 1 current, to an apex 2 current, and back again to a final current. Irupdn objects are normally used for cyclic scans. The object encapsulates information about the initial, apex and final currents, the ramp rates, and the data-acquisition rate.
The current range used for the Irupdn signal generator is selected from the largest absolute current limit (Initial, Final, Apex) in the waveform. The current range is fixed throughout the scan. The program does the best it can to reach lower current limits using the current range in use. Generally the smaller limits are only imprecise if they differ from the first by several orders of magnitude.
Irupdn objects use a staircase waveform. Data are sampled at each level on the staircase.
If the Skip button is "pressed" during the initial or second phase of the run, the Irupdn signal generator advances to the next phase. If the Skip button is pressed during the final phase, the Curve.Run() ends prematurely.