Program features 45Special acceleration/deceleration rampsThe acceleration/deceleration times for the jogging function can be definedseparately; see section Jogging (page 57).The change rate of the motor potentiometer function (page 70) is adjustable. Thesame rate applies in both directions.A deceleration ramp can be defined for emergency stop (“Off3” mode).Settings• Speed reference ramping: Parameters 23.11…23.19 and 46.01(pages 213 and 316).• Torque reference ramping: Parameters 01.30, 26.18 and 26.19(pages 117 and 236).• Frequency reference ramping: Parameters 28.71…28.75 and 46.02(pages 245 and 316).• Jogging: Parameters 23.20 and 23.21 (page 216).• Motor potentiometer: Parameter 22.75 (page 211).• Emergency stop (“Off3” mode): Parameter 23.23 Emergency stop time(page 216). Constant speeds/frequenciesConstant speeds and frequencies are predefined references that can be quicklyactivated, for example, through digital inputs. It is possible to define up to 7 constantspeeds for speed control and 7 constant frequencies for frequency control.WARNING: Constant speeds and frequencies override the normal referenceirrespective of where the reference is coming from.SettingsParameter groups 22 Speed reference selection (page 205) and 28 Frequencyreference chain (page 239). Critical speeds/frequenciesCritical speeds (sometimes called “skip speeds”) can be predefined for applicationswhere it is necessary to avoid certain motor speeds or speed ranges because of, forexample, mechanical resonance problems.The critical speeds function prevents the reference from dwelling within a critical bandfor extended times. When a changing reference (22.87 Speed reference act 7) entersa critical range, the output of the function (22.01 Speed ref unlimited) freezes until thereference exits the range. Any instant change in the output is smoothed out by theramping function further in the reference chain.
