What are the types of Speed Feedback for the 590+?

The Speed feedback modes are Encoder, Analog Tachometer and Armature Voltage.

• Armature Voltage is considered "Open Loop" as it relies solely on the armature voltage being read out to the motor and no additional option. You can not use this feedback mode to enter field weakening or control the current.
• Encoder and Analog Tachometer are considered "Closed Loop" and can be used to enter field weakening and control the current. Both require an additional option card to be purchased with the 590+ and are mutually exclusive. The encoder does provide a better feedback signal than the tachometer, and thus can achieve a higher degree of accuracy/precision.

[QuickLink for the 590+ on Parker.com] - Manual, QuickStarts, Product Support, etc