The Emerson PACSystems Railbus Isolator Carrier is used, together with the 8922-RB-IS Railbus Isolator, to isolate the 2/2 modules from the 2/1 modules. The carrier can be used with either 32- or 64-module addressing. It can be mounted on T or G section DIN-rail or directly to a flat surface, and may be joined end to end with I/O Module Carriers.