Control circuitry of a motor drive provides commands for operation of power circuitry in cooperation with peripheral circuits and devices, such as converters, inverters, feedback precharge circuits, feedback devices, interfaces, and so forth. The communications with the devices is handled by fiber optic communications circuitry that implements a flexible scheme of dynamic interval communication depending upon the capabilities and design of the peripheral circuit or device. The communication may be in accordance with a plurality of predetermined schemes, each having different data transfer rates, data allocations, and so forth. The schemes may each set communications protocols (e.g., timing) over a high speed interface between the fiber optic communications circuitry on one side and over fiber optic cables to the peripherals on another side.