Atlas Copco PowerMACS 4000, User Manual

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Tightening
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6.5.6.1 Ramps & Other
– Ramps
The Speed ramp up parameter controls the ramp of the step start and is important to tune to the process
in order to avoid unecessary damage and wear of equipment.
The speed ramps defined on a step can be smooth or straight. Straight ramps are defined by a linear
equation while smooth follows an S-function. The type of ramp to use is selected in the parameter
Ramps .
If needed, you can control every aspect of a step‟s speed curve by use of
Ramp data parameters.
Time
Speed
Speed
ramp up
Target
speed
New
Target
speed
Down
ramp
Down ramp start point
Smoothened ramps
Straight ramps
Up to five speed changes can be made during a step. These are defined as Ramp data entries.
When to change speed can be triggered by one of the following conditions:

Angle reaches a specified value

Torque reaches a specified value

Current reaches a specified value

A specified time from step start
Chose type by selecting the wanted type in the Start column and specify the trig value in the Level
property. Enter the new target speed in Speed and the acceleration/deceleration to use in Ramp [rpm/s].
Only one of the start conditions is monitored at the time. The second condition will not be checked until the
first condition has been met, and so on. However, there is no check done that the speed has reached the
final value of the first condition before the second is activated.