The powerful, high speed 4953A Protocol Analyzer with most common protocols standard! Included are BSC, DDCMP, HDLC, SDLC, X.25, X.75 and custom Character Oriented Protocols. Sophisticated tests are quickly and easily composed, softkey guided measurements and full ASCII keyboard. Sixty three triggers allow the 4953A to automatically react to character strings, error conditions, timers, and lead changes. Built-in tape drive allows storage and retrieval of data/set-up information. Other features include 50 bps to 72 Kbps transfer rates (int. clock or ext. clock), Synchronous, Asynchronous, and Synchronous NRZI, 64 Kbytes for storing data, timing, and face lead status, 48 Kbytes for storing application programs, total control of up to 16 remote instruments , timers/counters (5 each), plus a wide range of Data Codes, Error Checking, and Parity selection.