Danfoss MCO 305 Design Manual page 9

MCO 305 Design Guide
__ How to Read this MCO 305 Design Guide __
Master Units [MU]
A factor (fraction) is used for the conversion into qc, as with the user unit:
par. 33 − 10 Synchroniz ation Factor Master
1 Master Unit MU =
par. 33 − 11 Synchroniz ation Factor Slave
par. 33-10 Synchronization Factor Master SYNCFACTM
par. 33-11 Synchronization Factor Slave SYNCFACTS
Open Loop vs. Closed Loop
Open loop is control without feedback. Closed loop control compares velocity or position feedback with the
commanded velocity or position and generates a modified command to make the error smaller. The error is
the difference between the required speed and the actual speed.
Open loop can be used on systems where motor velocity is not critical, and where accurate positioning is
not necessary. Applications such as fan and blower control, pump control, and some low-end home
appliances are examples.
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