Atlas Copco PowerMACS 4000, User Manual

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Tightening
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6.5.4.11 Check Zero Crossing (only available for Gauging)
Parameters: Zero Crossing high, Zero Crossing low, Torque Rate Check, Set null position
Function: This check is not possible to run by itself, it use the data collected by a Check Toque Rate
check. The torque rate check to use is selected with the parameter
Torque Rate Check .
The Zero crossing check use the calculated torque rate line in the torque rate check (
T = TR
* A + m ) to calculate the zero crossing point, i.e. the angle there the toque is zero.
The zero crossing ZC is calculated as:
ZC = -m / TR
The angle used is the cycle angle, so the result will be angle from cycle start and not angle
from step start. The check will use the angle channel selected in the torque rate check.
The calculated
ZC is compared with the limits Zero Crossing High and Zero Crossing
Low . If Set Null position is checked this position will also be stored to make it possible to
return to that point with the step Run to Position