The RS 232 – USB adapter cable with test access is an adapter manufactured by Gossen Metrawatt and designed to allow connection between a computer via USB and an RS232 device such as a printer or modem. The adapter is designated the GM-K852A, GM-K853A, GM-K854A, and GM-K855A, depending on the type of cable that is needed for connection.The adapter is equipped with test access, allowing technicians to measure current, voltage and resistance on the RS232 side of the connection. In addition, the adapter facilitates communication between the USB-side of the connection and the RS232 side, allowing for data transfers between both sides. The adapter also has an indication LED that illuminates when power is detected and indicates whether the adapter is transferring data or not.