There are three parameters in the S300, S600, and S700 drives that define the acceleration limits, or maximum acceleration ramp and deceleration ramp. ACC and DEC are the acceleration and deceleration limits in the velocity loop. They are labeled in DriveGUI software as "Acc. Ramp" and "Dec. Ramp". In the Drive.exe software for the S600, the labels are "Setp. Ramp +" and "Setp. Ramp -". When the drive is in velocity mode, these are the only acceleration limits that apply. They are user defined and specific to each individual application.