The HP 37701B T1/Datacom Tester offers you a complete measurement solution for the installation and maintenance of T1, fractional T1 and datacom circuits and services in a single, portable box. In addition to the telecom measurements of the HP 37701B, you can add datacom capability to the tester by attaching the datacom module (HP 15901A Option 002). This module includes interfaces for RS-232-C, RS-449 and V.35 for rates up to 1.544 Mb/s, using its built-in synthesizer. An RS-232-C break-out box and control-circuit timing analysis help you identify interface faults.