Data link isolater

A module which isolates the common-mode signals between input and output was developed. The isolation is required because the zero level in two separated systems which are situated at a distance from each other is never the same. The module consists of two parts connected by optocouplers; one part is fully isolated from the Earth; both parts consist of a line receiver, a line driver, and a power supply. The maximum voltage between input and output of the optocouplers is 1000 V. The maximum bit rate of the module is 5 MB/s. The link via this module fulfils the RS422 standard and is fully duplex.