A measurement device including a measurement unit, a signal processing unit having a serial interface and connected to the measurement unit for processing signals obtained at the measurement unit, and a photocoupler connected to the serial interface of the signal processing unit for converting processed...http://www.google.com.au/patents/US6108618?utm_source=gb-gplus-sharePatent US6108618 - Method for optically transmitting signals in measurement units and measurement system employing the optical transmission method
