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.
