ABB has developed optional crane control software for its drives rated from 0.55kW to 5.6MW. The dedicated software incorporates all of the functions commonly required for hoist, trolley and long-travel motions in industrial, harbour and tower cranes.

The software uses the company’s DTC (direct torque control) technology to enhance safety and provide accurate low-speed control with high levels of torque, with or without encoder feedback from the motor shaft. A library of 15 easy-to-program function blocks eliminates the need for an external PLC. The software can accommodate different start torque methods, and includes a brake monitoring function for start, stop or running sequences.

Integrated brake control logic uses torque memory and pre-magnetising to open and close mechanical brakes reliably. In master/follower applications, the drives for up to five motors can be interlinked by fibre optics. Other facilities include: a function for checking electrical and mechanical systems; a load speed control that maximises the hoist speed for a given load and ensures that there is sufficient torque in the field-weakening area; a “slow down” function that limits the speed to a safe level in critical zones; and a speed monitor function to ensure that the crane motor speed stays within safe limits.