Technical information

182
230V FX Series Positioning Drive Reference Manual
Duty Cycle
For a repetitive cycle, the ratio of on time to total cycle time;
Duty Cycle = On Time / (On Time + Off Time) * 100%
Dynamic Braking
A passive technique for stopping a permanent magnet brush or brushless motor. The motor windings are
shorted together through a resistor which results in motor braking with an effectiveness of velocity/resistor
value.
Efficiency
The ratio of output power to input power.
Electrical Time Constant
The ratio of stator inductance to stator resistance.
Electronic Gearing
A technique used to electrically simulate mechanical gearing. Causes one closed loop axis to be slaved CW
and CCW to another open or closed loop axis at a programmable ratio.
EMI - Electro-Magnetic Interference
EMI is noise which, when coupled into sensitive electronic circuits, may cause problems.
Enable
An input which, when true, allows the circuit to function.
Encoder
A type of feedback device which converts mechanical motion into electrical signals to indicate actuator
position. Rotary encoders are typically designed with a transparent disk imprinted with opaque lines
radically oriented from the center of the encoder and a light source. As the disc turns with the actuator shaft,
the light source shines through the printed pattern onto a sensor.
The light transmission is interrupted by the patterns on the disc. These interruptions are sensed and
converted to electrical pulses. By counting these pulses, actuator shaft position is determined. Linear
encoders operate similarly except the printed lines cross the travel direction to directly indicate linear
position.
Encoders are generally one of the most accurate feedback devices - approximately 10 times the accuracy of
a resolver feedback system. Encoders are generously considered to be incremental devices unless
specifically designated as absolute encoders. Rotary encoders generally have resolutions of 250 to 5000
lines per revolution. Linear encoders generally have resolutions of 500 to 1000 lines per inch of travel. Units
are typically expressed in lines per revolution.
Encoder, Absolute
A digital position transducer in which the output is representative of the absolute position of the input shaft
within one (or more) revolutions. Output is usually a parallel digital word. Absolute encoders are generally
5 to 10 times the cost of incremental encoders.
Encoder, Incremental
A position encoding device in which the output represents incremental changes in position. (see Encoder)