Evaluation of distance coded measurement marker fields of incremental - for length and angle measurement using condition and reference markers for increased reliability, noise immunity

摘要

Evaluating distance coded measurement marker fields of incremental scale carriers involves sensing reference markers with a sensing head contg. a counter grid and photoelectric receiver. The reference markers have a fixed electrical and geometric relationship to a measurement scale. When condition markers (4, 5) either side of the scale (2) are sensed during scale carrier scanning a trigger clock pulse is sent to a collection register (9). The pulse is clocked through a gate (11) by two independent control signals and the register set into data collection or transmission mode. USE/ADVANTAGE - The reliability and noise immunity of incremental length and angle measurement systems are increased.