Rockwell Automation has added a number of logic functions to its
PowerFlex 40 ac drive range, including step logic, basic logic, timer and
counter functions, which avoids the need for a separate micro-controller.
The step logic facility for repetitive machine cycles allows the drive to
step through eight preset speeds, based on programmed logic (ie
conditions that need to be met before stepping from one to another preset
speed). The additional basic logic, timer and counter functions provide
extra programming options such as initiating an output change following a
set time elapse or number of counts. Programming is via an integral
keypad or from a remote PC over RS485.