A PC with Sealevel PCI RS-422 Serial Adapter (Part# 7201, 7204, or 7205) or USB SeaLINK RS-422 Serial Adapter (Part# 2202, 2203, 2402, or 2403), connected to Studio Gear with a Sealevel CA190 cable. The CA190 cable is available for use with any Sealevel DB9 RS-422 serial adapter.