| 摘要 |
<p>For rendering the signals developed by a shaft encoder less susceptible to corruption by transmission noise the invention provides a signal processor within the shaft encoder which processes the raw signals from the shaft encoder transducers into a condition more suitable for transmission over relatively long distances. In one embodiment, a shaft encoder produces three discrete output pulse trains providing frequency and phase information representative of speed and direction of rotation and instantaneous position of a shaft, and the invention provides a signal processor which detects unique logical states existing across the three pulse trains and outputs a correspondingly pulse width modulated signal for transmission, advantageously via an optical fibre transmission line, to a receiver decoder. In another embodiment, the output pulse trains of the shaft encoder are processed under microprocessor control by a signal processor provided in the shaft encoder and an output data signal is developed in a format which is adapted for remote transmission and includes error checking and correcting facilities.</p> |
