ABB ACS880-01 Series, Firmware Instructions

Page: 80 / 664

80 Program features
Special acceleration/deceleration ramps
The acceleration/deceleration times for the jogging function can be defined
separately; see section
Jogging (page 92 ) .
The change rate of the motor potentiometer function (page 106 ) is adjustable. The
same 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 257 and 364 ).
• Torque reference ramping: Parameters 01.30 , 26.18 and 26.19
(pages 154 and 282 ).
• Frequency reference ramping: Parameters 28.71 … 28.75 and 46.02
(pages 291 and 364 ).
• Jogging: Parameters 23.20 and 23.21 (page 260 ).
• Motor potentiometer: Parameter 22.75 (page 255 ).
• Emergency stop (“Off3” mode): Parameter 23.23 Emergency stop time
(page 260 ).
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Constant speeds/frequencies
Constant speeds and frequencies are predefined references that can be quickly
activated, for example, through digital inputs. It is possible to define up to 7 constant
speeds for speed control and 7 constant frequencies for frequency control.
WARNING: Constant speeds and frequencies override the normal reference
irrespective of where the reference is coming from.
The constant speeds/frequencies function operates on a 2 ms time level.
Settings
Parameter groups 22 Speed reference selection (page 249 ) and 28 Frequency
reference chain (page 285 ).

Critical speeds/frequencies
Critical speeds (sometimes called “skip speeds”) can be predefined for applications
where it is necessary to avoid certain motor speeds or speed ranges because of, for
example, mechanical resonance problems.
The critical speeds function prevents the reference from dwelling within a critical band
for extended times. When a changing reference (
22.87 Speed reference act 7 ) enters
a critical range, the output of the function ( 22.01 Speed ref unlimited ) freezes until the