Keysight (Agilent) U2781A USB Modular Product Chassis

The Keysight U2781A is a 4U chassis designed to house up to six Keysight USB modular instruments and data acquisition devices. It integrates a 200 W universal AC power supply with built-in over-current protection, temperature monitoring via dual sensors, and active cooling to maintain optimal operating conditions. The chassis excels in applications requiring precise multi-module synchronization—a capability that reduces test costs and accelerates system integration across R&D, design validation, and manufacturing environments.

– Technical Specifications

Chassis Architecture
• Capacity: Up to six Keysight USB modular products
• Power supply: 200 W universal AC, 100–240 VAC input
• Protection: Over-current protection circuit
• Thermal management: Two temperature sensors and built-in fan

Synchronization & Timing
• Star Trigger Bus: Dedicated trigger lines for external trigger input and synchronized triggering between modules
• Simultaneous Synchronization Interface (SSI): Primary/Secondary module configuration for intra-chassis synchronization
• Internal reference clock: 10 MHz per module slot; external 10 MHz reference input via BNC connector

Connectivity
• USB: High-Speed USB 2.0 and USBTMC-USB488 compliance
• Command interface: SCPI remote control

– Key Features

• Module synchronization reduces test costs and accelerates integration
• Dual temperature sensors with automatic fan control maintain thermal stability
• Star Trigger Bus enables precise external and inter-module triggering
• 10 MHz reference clock distribution ensures coherent multi-module measurements
• Supports external reference clock input for system-level synchronization

– Typical Applications

• Industrial and scientific R&D
• Design validation and characterization
• Manufacturing test and quality assurance
• Multi-channel data acquisition requiring synchronized measurements

– Compatibility & Integration

The chassis supports Keysight U2300 Series (multifunction DAQ), U2500 Series (simultaneous sampling DAQ), U2600 Series (isolated digital I/O), U2701A/U2702A (USB oscilloscopes), U2722A/U2723A (source measure units), and other compatible modular products. Software integration includes Keysight VEE, MATLAB, NI LabVIEW, Microsoft Visual Studio, and Keysight Measurement Manager. Channel expansion is substantial—six U2331A units deliver up to 384 channels for high-density acquisition applications.