Solution
When going through load startup from 0 A when the PXIe-4051 load is off, there can be additional delay prior to the current ramping up. This behavior is expected due to the analog control loop needing time to ramp up to prevent current overshoot, voltage overshoot, or voltage undershoot. This behavior is most pronounced when using small current setpoints or the Gain Bandwidth is low. To work around the startup delay, it is recommended to test with higher initial current setpoints, increase the Current Gain Bandwidth value, or use a higher than 0 A initial sinking step prior to configuring the load to the desired current setpoint.