The Aeroflex IFR 2843 Digital Communications Analyzer is a hand-held analyzer for installation and maintenance measurements on digital 2 Mbit/s lines and equipment with data interface testing ability. 2 Mbit/s framing systems with 30 and 31 channels, with and without CRC4, are generated and received to enable a range of tests on framing, alarms and signaling. Individual channels can be tested at 64 kbit/s, assisting in testing and fault location within digital data networks and cross connect switches. n x 64 kbit/s channels can be tested where they are carried within 2 Mbit/s digital signals. 2 Mbit/s and data circuits and equipment can be tested in a fully integrated test instrument, with mixed mode data and 2 Mbit/s testing possible for maximum flexibility. Data test interfaces provided are RS-232, X.21, V.35, RS-449 (V.36), codirectional and contradirectional. Both synchronous and asynchronous modes are possible with a wide range of standard and user programmable data rates. Independent transmitter and receiver enable connection to data and 2 Mbit/s interfaces simultaneously. Dual receiver inputs enable connection of two 2 Mbit/s HDB3 signals for measurement of clock slips. Voice channels within a 2048 kbit/s signal on either receiver can be monitored in-service (A/B Audio) and routed to an internal loudspeaker or a headphone socket for a first level check of analog level and quality. 64 kbit/s data channels can be routed to a V.11 interface for external measurement, for example connection of common channel signaling to a protocol analyzer.