Atlas Copco PowerMACS 4000, User Manual

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6.5.4.7 Check Post view Torque
Parameters: TC (Torque check level),
TL (Torque low), AdistL (Low angle distance), AwinL (Low angle window),
NOSL (No samples low)
TH (Torque high), AdistH (High angle distance), AwinH (High angle window),
NOSH (No samples high)
Function: This function checks that the filtered torque in the angle window AwinL is higher than the
torque limit TL. It also checks that the filtered torque in the angle window AwinH is less than
the torque limit TH. Both limits are optional but at least one of them must be specified.
Angle window AwinL is located AdistL before the point where the torque reaches level TC
and AwinH is located AdistH before the torque reaches level TC. The torque level is allowed
to reach level TC several times during a step. The angle windows are measured from the
last point where the torque reached TC.
The torque values used in the check are filtered using a sliding window average algorithm.
The mean torque value is calculated over NOSL for the TL check and over NOSH for the
TH check. The filter can be disabled by leaving the respective number of samples
parameter empty.
The filter starts after the torque spike elimination phase and runs throughout the check. The
check does not start until the filter is full. The filtered torque value is recalculated on every
new sample; that is, normally every millisecond.
The angle used for crossings ove
r the limits is the filter‟s median angle value (angle at
sample NOSL/2 or NOSH/2 in the filter).
This check requires that torque TC is reached after the torque spike elimination phase and
that the angle MAX(AwinL + AdistL; AwinH + AdistH) has been reached at that point. If not,
the steps status is set to
Fatal and the error bit of the respective limit is set.