New features for Impact AC drive

Rockwell Automation has announced the addition of three new features to its Allen-Bradley 1336 Impact AC drive. The inclusion of speed profiling, encoder/encoderless switchover and an encoderless-with-deadband option broadens the applications for the drive, says the company.

The new embedded speed profiling features gives users the flexibility to run applications at a specified speed. This can be based on time, encoder counts or hardware inputs through the L-option card, saving panel space and costs associated with an external controller.

For applications requiring repeatable speed-step changes, such as turntables, gantries, run-out tables, transfer shuttles, palletisers and station gates, the 1336 Impact with speed profiling can be programmed for a series of up to 16 speed-step changes. These are based on either an encoder pulse count, a specific time interval or by toggling a digital input in the drive.

The sequence of the profile can be a single cycle with a return-to-home or a continuous loop with a return-to-step-one routine. For added application flexibility, each speed step has three parameters for configuration, including the step RPM speed, units of travel and the type of index or move needed to perform.

The drive also features Force Technology, a patented, field orientated control technology developed by Rockwell Automation. This permits the independent control of speed and torque, providing high performance control of standard AC induction motors. Speed profiling brings the added flexibility of defining speed-step changes to demanding motor control applications.

The encoder/encoderless switchover function automatically switches from encoder feedback to encoderless operation without disrupting the drive. This is achieved by running the drive in encoderless mode and using the process trim loop as an outer speed trim loop. This feature is intended for continuous casters and similar applications.

The encoderless-with-deadband option is effective when the drive is operating below one hertz in encoderless mode. For low speed applications, such as extruders, this eliminates cogging at low speeds by generating a zero-speed command while operating below one hertz.