The present invention relates to maintaining bioactive molecules in their native or substantially near-native form and preventing or reduce aggregation. In one embodiment, the method comprises detecting a miscabling defect at the node; setting a state of a miscabling parameter to true in a protection state machine of the node; and responsive to the setting, notifying a neighboring node of a signal failure. The controller separates the PWM signal into a high-side signal and a low-side signal.