Abstract: A system and method for monitoring messages containing command, status, and data words transmitted on a high speed, serial, asynchronous AS1773 fiber-optic data bus employing Manchester encoding includes a fiber-optical receiver connected to the data bus and adapted to receive and convert optical signals into message words containing either a command, a status, or a data word. The system also preferably includes a memory device having a number of storage locations adapted to receive and store the message words, which is organized in an optimal fashion to allow the system to monitor high speed data buses. Preferably, a logic device is operationally coupled to the fiber-optical receiver and adapted to serially receive and process each message word. The logic device controls the transfer of each message word into one of the memory locations of the message buffer.