Agilent/Keysight 3787B

The Agilent/Keysight 3787B is a Digital Data Test Set (BERT) engineered for in-service and out-of-service testing of T1 leased lines, Digital Data Systems (DDS), 56 kbit/s switched services, and Packet Switched transmission equipment. It delivers bit error rate measurement, full error analysis, frame slip detection, and signal-level monitoring across multiple digital hierarchies. The instrument integrates transmit and receive capability with built-in multiplexer/demultiplexer functions for inserting or extracting test patterns, control codes, and external data into individual timeslots, subrates, and overhead channels.

Technical Specifications

• Supported Interfaces: DS0 A/B, DS1 (D4, ESF, T1DM, SLC-96), DS1C, DDS/Dataport


• Operating Frequencies: DS0 at 64 kbit/s; DS1 at 1.544 Mbit/s; DS1C at 3.152 Mbit/s


• Framing: DS1, DS1C, and DS0B


• Line Codes: B8ZS, AMI


• Test Patterns: 2^15, 2^20, 2^23 PRBS; QRSS, 3 in 24, 8-bit word, loop, and control codes; TA55 DDS stress patterns; 256-byte user-defined pattern (DS0 only); logic (binary) patterns


• Jitter Measurement: Optional DS1 jitter measurement (Option 001)

Key Features

• Full transmit and receive capability with built-in multiplexer/demultiplexer


• Comprehensive bit error rate measurement and full error analysis


• Error detection and logging on all test patterns


• Availability metrics: % Availability, % Unavailability, % Severely Errored Seconds, % Error Seconds, % Degraded Minutes


• Frame slip measurement and analysis


• Signal level and DS1/DS1C signal voltage measurement


• DS0 bit monitor and signaling bit analysis


• ISDN 'B' or 'D' Channel Protocol Analyzer capability


• External clock input for jitter generation


• Built-in data logging and printer


• Remote control via HP-IB and RS-232

Typical Applications

• T1 leased line characterization and troubleshooting


• DDS and 56 kbit/s switched service validation


• In-service circuit deterioration and intermittent detection


• Out-of-service loopback testing with T1/DDS codes


• Packet-switched network transmission verification

Compatibility & Integration Remote control interfaces include HP-IB and RS-232 for integration into automated test environments and network monitoring systems.