It has many code rings with different binary weightings which provides a digital data word representing the absolute position of the encoder within one revolution down to the precision of the least significant bit. Adding more bits will divide one revolution into smaller segments, and the encoder will, therefore, provide higher resolution. Multiple revolutions may be indicated by additional code discs which are gear driven to give count of multiple turns. The Absolute Encoder is unique because it will report the absolute position of the encoder to the electronics. It will do this as soon as it is powered up with no need for indexing.
Incremental Encoders:- It has many code rings with different binary weightings which provides a digital data word representing the absolute position of the encoder within one revolution down to the precision of the least significant bit. Adding more bits will divide one revolution into smaller segments, and the encoder will, therefore, provide higher resolution. Multiple revolutions may be indicated by additional code discs which are gear driven to give count of multiple turns. The Absolute Encoder is unique because it will report the absolute position of the encoder to the electronics. It will do this as soon as it is powered up with no need for indexing.
Incremental Encoders:- These operate by photoelectric scanning of the fine lines on the rotating disk. Incremental Encoders provide A and B pulse outputs. Pulse outputs provide no usable count information in their own right. With an incremental encoder the counting is done by external electronics. The output on lines A, B and Z are checked with an oscilloscope. Accurate count checks are done with pulse counting device.
Typical Tests:
- Check the pulse stream of all wave forms with an oscilloscope
- Check the relationship of the A, A*, B, B* signals with and oscilloscope
- Check the Z, Z* signals with an oscilloscope
- Line level check all lines to verify that none are missing
- Line count with a digital pulse counter
- Run at continual count at operating speed check,
- Measure the offset from signal A to signal B.
- Measure the "on" versus the time "off" of the pulses.