A cable isolator is provided for automatically performing cable breaks for testing of host bus adapters. A workstation includes a host bus adapter, such as a Fibre Channel storage controller, to be tested. The host bus adapter is connected to one or more storage modules through the cable isolator. The cable isolator includes two transceivers, one of which is connected to the host bus adapter and the other being connected to the storage modules. The two transceivers are also connected to each other internally. The cable isolator also includes a programmable logic device or controller that is used to enable and disable the two transceivers at set intervals. When the cable connection is to be broken, the programmable logic device generates one or more output disable signals. The one or more output disable signals are then provided to the transceivers to perform the cable break. An on-time and an off-time may be set using switches or dials.