The HP/Agilent 4951C Protocol Analyzer is a portable instrument for installation, maintenance, and design of data communication networks. It captures, analyzes, and simulates protocol traffic across multiple serial interfaces, supporting data rates from 50 bps to 19 kbps. Real-time monitoring, post-processing of stored data, bit error rate testing, and device emulation enable rapid network troubleshooting and performance assessment across legacy communication systems.
## Technical Specifications
**Data Rates:** 50 bps to 19 kbps
**Protocols Supported:**
• Asynchronous (Async)
• BSC
• SDLC (NRZI)
• HDLC
• X.25
• SNA
• DDCMP
• User-defined protocols
**Storage:** 3 ½-inch diskette (618 KB capacity) for data, timing, lead status, programs, and configurations; nonvolatile memory for persistent program and configuration storage
**Power Input:** 100 – 240 VAC, 48 to 66 Hz; three-conductor grounded power cord
**Serial Interfaces:** RS-232C/V.24, RS-449/422A/423A, MIL-188C, V.35
**Interface Pods:** HP 18177A, HP 18180A (combination RS-232/V.24 and RS-449/422A/423A), HP 18179A (RS-232C/V.24 with breakout box), HP 18174A (RS-449/422A/423A)
**Video & Printer:** RS-170 video output port; dedicated RS-232/V.24 ASCII printer port
## Key Features
• Auto Configure determines line parameters for immediate monitoring
• Live line or buffer capture with post-processing analysis
• DTE/DCE device emulation for network component testing
• Bit Error Rate Testing (BERT) for line quality assessment
• Data Communications Test Library with pre-written programs
• 3270 cluster emulation (optional HP 18332D software)
• Link-level statistical analysis for SNA and X.25 (optional HP 18333D)
• Full ASCII keyboard with softkey-driven menu interface
• Remote control via PC utilities for distributed analysis
## Typical Applications
Legacy network installation and commissioning; protocol-level troubleshooting of asynchronous, BSC, and SNA systems; line quality validation; device simulation for cluster testing; performance characterization of serial data links.
## Compatibility & Integration
PC utilities enable remote control and protocol data analysis. User-defined programs and configurations load from 3 ½-inch diskette storage.
