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Programming Your Application
1-21
690+ Series Frequency Inverter
Functional Description
The FIXED INERTIA is the inertia of the motor, gearbox and core. The VARIABLE INERTIA
is the inertia of the roll. A WIDTH input is available for setting the web width.
The total inertia (INERTIA COMP) is multiplied by the scaled acceleration rate to produce the
torque demand. The polarity is set by the unwind/re-wind selection.
Accelerating a rewind requires additional torque in the same direction as the tension producing
torque, whereas an unwind will require accelerating torque in the opposite direction to the
tension torque. The acceleration rate comes from the line speed demand input. The line speed
demand input is differentiated to produce a rate.
DIAMETER
VARIABLE INERTIA
MINIMUM DIAMETER
FIXED INERTIA
WIDTH
-
+
COMPENSATIONS
LINE SPEED RATE
INERTIA COMP
SCALED RATE
LINE SPD DEMAND
RATE CAL
chs
u
1
x1
X3
REWIND
MOD WINDER SPEED
DYNAMIC COMP
STATIC COMP
+
chs
+
MINIMUM DIAMETER
DIAMETER
Varible Inertia
Fixed Inertia
Static & Dynamic
REVERSE
chs
Derivitive Calc
x
1
dx
dt
1
u
u
1
x1
X3
Parameter Descriptions
INERTIA COMP
Range: —.00 %
Unscaled inertia compensation diagnostic.
SCALED RATE
Range: —.00 %
Scaled rate diagnostic.
LINE SPEED RATE
Range: —.00 %
Differential of line speed.