Specifications include, but are not limited to: Modernize TMS50 MRLs Controller A new microprocessor-based control system shall be provided to perform the functions of safe elevator motion. Included shall be all of the hardware required to connect, transfer and interrupt power, and to protect the motor against overloading. The control for the hoist motor will be by means of a solid-state drive system. The system will be a controlled pulse-width modulated AC vector drive. The variable voltage variable frequency drive will convert the AC power supply using a two-step process to a variable voltage variable frequency power supply for use by the hoist motor. Varying the frequency and voltage of the motor will automatically and continuously control the speed, acceleration and deceleration. The system will be closed loop. Each controller cabinet containing memory equipment shall be properly shielded from line pollution. The microcomputer system shall be designed to accept reprogramming with minimum system down time.