The Agilent/Keysight 3784A is a portable Digital Transmission Analyzer for error performance and jitter testing in manufacturing, commissioning, and maintenance of network equipment. It supports CEPT telecom interface rates from 704 kb/s to 34 Mb/s, optional codirectional interfaces at 64 kb/s, V.11 interfaces for X.21 leased circuits, and binary TTL/ECL interfaces up to 50 Mb/s using an internal clock synthesizer. The instrument delivers G.821 error analysis, automated jitter tolerance and transfer function measurements, and in-service error performance monitoring via line code error detection.
Technical Specifications
Supported Interface Rates:
• Standard telecom interfaces: 704 kb/s, 2 Mb/s, 8 Mb/s, 34 Mb/s
• Optional codirectional interfaces: 64 kb/s
• Optional V.11 interfaces for X.21 leased circuits
• Binary TTL/ECL interfaces: 1 kb/s to 50 Mb/s (internal clock synthesizer)
• Optional measurements at DS1, DS1C, DS2, and DS3 rates
• Optional measurements at 140 Mb/s
Measurement Parameters:
• G.821 error analysis
• Error count, error ratio, error and error-free intervals (seconds and deciseconds)
• Percent unavailability, percent errored seconds, percent severely-errored seconds, percent degraded minutes
• Peak-to-peak jitter amplitude
• Jitter-hit count and hit-free intervals (seconds or deciseconds)
• Jitter generation and measurement (optional)
• Jitter tolerance and transfer function measurements (fully automated)
• In-service error performance monitoring using line code error detection
• Through-data mode for injecting jitter into structured signals
– Key Features
• Measurement presets and automatic receiver setup
• Configurable error performance pass/fail thresholds
• Automated jitter tolerance and transfer function plotting routines
• Long-term unattended measurements with data logging to internal or external printer
• Through-data mode enables jitter tolerance testing of demultiplexers
– Typical Applications
• Error and jitter characterization in telecom network equipment
• Demultiplexer jitter tolerance qualification
• G.821 compliance verification
• Manufacturing test and commissioning of DS1/DS3 systems
– Compatibility & Integration
The 3784A can be paired with other analyzers such as the Keysight 3764A for comprehensive error and jitter test capabilities.

















