Amplicon's own Model 232i is a self powered DB9 opto-isolator suitable for most RS232 applications. The electrical isolation of the port also provides a degree of protection against detrimental voltages. Supplied in a robust plastic case and dipped in metallic paint for the best EMC performance, the Amplicon Model 232i is an ideal industrial unit. A special feature is the ability to jumper-select isolation for any pair of handshaking lines. If handshaking is required for fully specified RS232, please call sales for details of an alternative unit. In accordance with good cabling practise, it may be necessary to disconnect the earth shield at one end. This is application dependent.