5.1.3
Explain the position sensors
c.
encoders
• Absolute
position encoders
– a pattern of light and dark strips is printed on to a
strip and is detected
by a sensor that moves along it
• the pattern takes the form of a series of lines as
shown below
• it is arranged so that the combination is unique at
each point
• sensor is an array of photodiodes
• Incremental
position encoder
– uses
a single line that alternates black/white
• two
slightly offset sensors produce outputs as shown below
• detects
motion in either direction, pulses are counted to determine absolute position
(which must be initially reset)
ENCODER COMMUNICATIONS :
ReplyDelete- The output of an incremental encoder is a stream of pulses on one or two channels,
while the output of an absolute encoder is a multi-bit word.
- . This can be transmitted
in either parallel or serial form.
source : https://www.dynapar.com/uploadedFiles/_Site_Root/Service_and_Support/Danaher_Encoder_Handbook.pdf