A motor drive for controlling three-phase controlled frequency AC power for driving a motor, the motor drive comprising: converter circuitry to convert incoming three-phase power to DC power; inverter circuitry to convert the DC power to the three-phase controlled frequency AC power to drive the motor ; a plurality of functional circuits each configured to carry out a control, monitoring, or feedback operation with respect to a driven motor or load; control circuitry coupled to the inverter circuitry and configured to: receive feedback signals, apply control signals to the inverter circuitry for conversion of the DC power to the three-phase controlled frequency AC power, and supply variable control events and/or system events to the functional circuits ; an option bus configured to manage communications to and from the functional circuits via one or more physical backplanes ; and the one or more physical backplanes providing data communication between the control circuitry and the functional circuits ; wherein the one or more physical backplanes have separate and independent conductive data lines for each functional circuit , thus allowing data transfer between the control circuitry and each functional circuit at different data transfer rates, wherein the one or more physical backplanes comprise one or more dedicated functional circuit support boards configured for data transmission only, characterized in that the control circuitry employs different control event intervals and/or system event intervals with each functional circuit , wherein the different control event intervals and/or system event intervals are triggered by the option bus or the control circuitry , and wherein the control circuitry chooses clock rates, and thus data transfer rates, for each respective functional circuit based on the optimal performance for each respective functional circuit. converter circuitry to convert incoming three-phase power to DC power; inverter circuitry to convert the DC power to the three-phase controlled frequency AC power to drive the motor ; a plurality of functional circuits each configured to carry out a control, monitoring, or feedback operation with respect to a driven motor or load; control circuitry coupled to the inverter circuitry and configured to: receive feedback signals, apply control signals to the inverter circuitry for conversion of the DC power to the three-phase controlled frequency AC power, and supply variable control events and/or system events to the functional circuits ; receive feedback signals, apply control signals to the inverter circuitry for conversion of the DC power to the three-phase controlled frequency AC power, and supply variable control events and/or system events to the functional circuits ; an option bus configured to manage communications to and from the functional circuits via one or more physical backplanes ; and the one or more physical backplanes providing data communication between the control circuitry and the functional circuits ; wherein the one or more physical backplanes have separate and independent conductive data lines for each functional circuit , thus allowing data transfer between the control circuitry and each functional circuit at different data transfer rates, wherein the one or more physical backplanes comprise one or more dedicated functional circuit support boards configured for data transmission only, characterized in that the control circuitry employs different control event intervals and/or system event intervals with each functional circuit , wherein the different control event intervals and/or system event intervals are triggered by the option bus or the control circuitry , and wherein the control circuitry chooses clock rates, and thus data transfer rates, for each respective functional circuit based on the optimal performance for each respective functional circuit. <EOS>