The HP Agilent 37721A Digital Transmission Analyzer is a portable, lightweight, rugged test set providing bit and code error testing at the European CEPT rates of 704 kb/s, 2, 8, 34, and 140 Mb/s. It measures error performance to CCITT Recommendation G.821, with interfaces to G.703. A key feature of the 37721A is its ease of use: the autosetup facility automatically configures the test set to the incoming data; nine stored setups ensure that required test parameters are instantly available; graphic display of results shows error counts, error seconds, and alarms at a glance; and a range of logging options to an internal or external printer provides customized hard-copy proof of results.