TMC423_1 TRINAMIC [TRINAMIC Motion Control GmbH & Co. KG.], TMC423_1 Datasheet - Page 14

• Manufacturer Part Number: TMC423_1
• Description: Serial Triple Incremental Encoder Interface
• Manufacturer: TRINAMIC [TRINAMIC Motion Control GmbH & Co. KG.]

TMC423 Data Sheet – (V1.13 / June 20
6 Incremental Encoder
Incremental Encoders are translating the rotary motion of a shaft into a two-channel digital
quadrature output. The light emitted from a LED is focused onto a reflective code wheel. As the shaft
moves, the code wheel rotates, reflecting light from an alternating bright and dark pattern.
The TMC423 samples the incoming signals ENCx_a and ENCx_B from the incremental encoder. A
internal algorithm block counts the amount of edges generated by the encoder. A prescaler value can
be used to adapt the incremental encoder resolution to the stepper motor resolution.
For high resolution the TMC423 evaluates the encoder signals 4-times during each encoder step. This
has to kept in mind when choosing the prescaler value.
Note: It is possible that the encoder signals ENCx_A, ENCx_B and ENCx_N are polluted with crosstalk
noise. Crosstalk could influence the internal logic, to overcome this problem internal filters are
applied to ensure correct functionality. Furthermore is saves the need for external analog filters.
e.g.: Figure 11: Crosstalk on Encoder Wire shows crosstalk from channel A to channel B.
Copyright © 2004 TRINAMIC Motion Control GmbH & Co. KG
Figure 10: Encoder Output and Evaluation
Figure 11: Crosstalk on Encoder Wire
Channel N
Channel A
Channel B
Evaluation
th
, 2007)
Step
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