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TB280 Rev1 รข Quadrature and Differential Encoder Errors
Differential and Quadrature Errors are typically caused by noise or the use of encoders
that do not meet Centroid signal level specifications To eliminate/reduce noise always
use shielded twisted pair cabling Also do not route encoder cables next to cabling for
high power 3 phase or inductive loads
1 Confirm that you encoders meet Centroid signal specifications Centroid requires
quadrature differential line driver encoders that meet the RS422/423 specifications In
addition the รขlowรข signal level must be < 5VDC and the รขhighรข must be >= 3 5VDC
2 A Differential Error is issued when the signal levels for รขHighรข and รขLowรข do not meet
Centroid specifications Centroid hardware will issue a Differential Error if either the รขLowรข
signal is > 0 5VDC or the รขHighรข is < 3 6VDC While not recommended it is possible to disable
Differential error faults for encoders 1 8 by setting parameter 332 to 255 To disable Differential
error messages for encoders 1 8 setting parameter 333 to 255 Additional information on
parameters 332 & 333 can be found in the Operators Manual
3 A Quadrature Error is issued when the bit pattern for the encoder signal is
not valid and/or does not match the expected pattern Quadrature errors are nearly always
caused by noise Because Quadrature errors can and often do effect machine position it is
imperative that the problem noise be corrected Because these errors often effect machine
position it is not recommended that theses errors be disabled While not recommended it is
possible to disable Quadrature error faults for encoders 1 8 by setting parameter 334 to 255
To disable Quadrature error messages for encoders 1 8 by setting parameter 335 to 255
Additional information on parameters 334 & 335 can be found in the Operators Manual
To enter the parameter screen from the Main screen press
F1 Setup >F3 Config pw=137 press enter >F3 Parms