Abstract: An elevator controller/solid state drive interface allows an existing relay logic passenger elevator controller to be retrofitted with either a DC or AC solid state drive replacing the motor generator set for DC hoist motors or the two-speed starter in AC systems. This interface can also allow systems utilizing a motor generator set and DC hoist motor to be retrofitted with an AC solid state drive and AC hoist motor while retaining the existing controller. The controller/solid state drive interface includes selectable dropping resistors to adapt to various control VDC from an existing elevator controller to a 24 VDC relay bank. An electrical circuit coupled to the relay bank (containing additional relays and timers) provides control signals to the solid state drive, which in turn provides the drive power to the hoist motor. Sequencing of specific control signals and creation of the functions necessary for proper operation of the solid state drive are provided within the controller/solid state drive interface.