serial To Fiber Optic Convertersstandards Can Be Mixed And Matched So Rs-232 Devices Can Be Connected To Rs-422/485 Devices, Replacing A Converter And Isolator. When Working With Rs-485 Signals, B&b Electronics'' Automatic Send Data Control Eliminates The Need For Driver Software. Serial Connections Are On Terminal Blocks; Multimode Fiber Side Has Two St Connectors. Requires External Power Supply Not Included.