User`s manual

212 • Vacon apfiff09 marine
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6
P2.13.20 FB Actual Speed ID1741
With this it is possible to select which Actual speed is shown on the fieldbus.
0 = Calculated
This selection shows what the ramp generator output is.
Open Loop
In frequency control mode when only the ramp output is shown on the fieldbus and,
therefore, the motor slip or any other changes of speed due to load changes are not
visible in the actual speed value. However, limiting functions are visible in the ramp
output.
Closed Loop
In closed loop control, the limiting functions take place after ramp generator. When
speed is limited by e.g. motoring torque limit the actual shaft speed may be lower even if
FB Actual Speed shows that speed is at reference.
1 = Actual
Open Loop
Motor speed is a calculated value (Monitoring variable Motor Speed) showing the load
affect on the speed and slip compensation.
Closed Loop
Motor speed is taken from the actual encoder signal showing the real speed all the time.