Encoders By Function
encoder functions
Linear Measurement
As the encoder generates pulses in response to linear displacement of the material or object to be measured, it is a matter of simple math for the receiving device to convert those pulses into distance.
Motor Feedback
The most common application of rotary encoders is for the control of speed and direction of electric motors, from small frame steppers to large AC induction vector-duty NEMA motors.
Web Tensioning
In industries where materials such as paper, plastic film, aluminum, fiber or wire must be wound on to a reel, web tensioning is a key portion of the manufacturing process that contributes to uniformity, quality and productivity.
Cut-To-Length
A rotary encoder is an ideal feedback device for cut-to-length applications. A fixed number of pulses is generated as the code disc rotates. These pulses can easily be correlated via scaling or simple counting to determine length of travel.
Registration Mark Timing
For registration mark timing, a rotary encoder is used to determine the position of an object relative to a known point, referred to as a registration mark. Encoder feedback is then used to determine the speed of an axis of motion in relation to the registration mark.
Backstop Gauging
A rotary encoder is used to ensure that the unit to be controlled, such as a machine tool, does not exceed a pre-set position or direction of travel. Very often, this encoder function is combined with determining the speed of travel of the table, tool head, or similar component
Filling
In many filling applications, a rotary encoder is used for table positioning. Feedback from the encoder helps ensure that the item to be filled is in the correct position prior to activation of the filling mechanism.
Conveying
Often conveyors are driven by simple constant-speed motors with minimal feedback requirements. Sensors and motion control devices come into play when conveyors are integrated with companion equipment, such as palletizers or labelers.
Spooling - Level Wind
In spooling or level wind applications, material such as cable or flat roll-stock is wound onto a spool. It’s critical to maintain the proper relationship between the speed of the take up spool and the supply spool, since the material on both reels changes diameter as it is winding.
X-Y Positioning
In X-Y positioning applications, such as automated pick-and-place, rotary encoders provide feedback on two axis of motion in order to determine X-Y coordinates. The encoder can be attached to the shaft of a ball screw or the drive motor of an actuator.
Ball Screw Positioning
The principal use of ball screw assemblies is to mechanically convert rotary motion into linear motion. A rotary encoder, when attached to the end of the ball screw shaft or the drive motor, provides feedback used to determine linear speed, direction, rate and position.
