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Program features 43
The change rate of the motor potentiometer function (page
) 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
and
(pages
and
• Torque reference ramping: Parameters
(pages
and
).
• Frequency reference ramping: Parameters
and
(pages
and
and
• Motor potentiometer: Parameter
(page
• Emergency stop (“Off3” mode): Parameter
(page
).
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
(page
) and
(page
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 (
) enters
a critical range, the output of the function (
) freezes until the
reference exits the range. Any instant change in the output is smoothed out by the
ramping function further in the reference chain.
Summary of Contents for ACS880-x04
Page 1: ... ABB INDUSTRIAL DRIVES ACS880 primary control program Firmware manual ...
Page 4: ......
Page 18: ...18 Using the control panel ...
Page 24: ...24 Control locations and operating modes ...
Page 112: ...112 Application macros ...
Page 496: ...496 Additional parameter data ...
Page 544: ...544 Fault tracing ...
Page 602: ...602 Control chain diagrams ...