SGMAH-01AAF41 Yaskawa Electric 100w Servo Motor Closed Loop Servo

Open Loop Operation
One of the most significant advantages of a stepper motor is its ability to be accurately controlled in an open loop system. Open loop control means no feedback information about position is needed. This type of control eliminates the need for expensive sensing and feedback devices such as optical encoders. Your position is known simply by keeping track of the input step pulses.
Stepper Motor Types
There are three basic stepper motor types. They are :
• Variable-reluctance
• Permanent-magnet
• Hybrid

Rotation occurs when the rotor teeth are attracted to the energized stator poles.
Permanent Magnet (PM) Often referred to as a “tin can” or “canstock” motor the permanent magnet step motor is a low cost and low resolution type motor with typical step angles of 7.5° to 15°. (48 – 24 steps/revolution) PM motors as the name implies have permanent magnets added to the motor structure.
The rotor no longer has teeth as with the VR motor. Instead the rotor is magnetized with alternating north and south poles situated in a straight line parallel to the rotor shaft. These magnetized rotor poles provide an increased magnetic flux intensity and because of this the PM motor exhibits improved torque characteristics when compared