This article describes the Excalibur 1394 card and how it may be used to test a 1394 product. IEEE 1394 is a communication protocol that enables high speed serial communication among multiple devices. The AS5643 standard defines how 1394 may be used to create a datanetwork. This standard is used in some military and aerospace vehicles, and the standard is implemented by the Excalibur 1394 card.