Distance-coded reference marks on linear encoders

In some cases this may necessitate machine movement over large parts of the measuring range. To speed and simplify such “reference runs,” many encoders feature distance-coded reference marks—multiple reference marks that are individually spaced according to a mathematical algorithm. The subsequent electronics find the absolute reference after traversing two successive reference marks—only a few millimeters traverse (see table). Encoders with distance-coded reference marks are identified with a “C” behind the model designation (e.g. LS 487C).