Agilent/Keysight 3235A

The Agilent/Keysight 3235A is a modular Switch/Test Unit (STU) mainframe designed to house plug-in modules for signal switching, measurement, and signal sourcing functions within automated test systems. The 3235A itself is not a standalone instrument but is the core chassis that accepts various plug-in modules and integrates them into a cohesive test platform. Its primary role is to provide high-integrity signal switching and act as the interface between test instrumentation and the device-under-test.

Technical Specifications

The 3235A mainframe is equipped with a 10-slot plug-in cage. System expandability is achieved through connection of up to seven HP 3235E extender frames, yielding a total of 80 slots across the entire system. Four backplane analog buses support isolated signal routing between modules and frames. Two trigger buses carry digital trigger signals. HP-IB interface support enables direct programming and control from external computers.

Key Features

• 10-slot plug-in module cage in mainframe


• Expandable architecture: supports up to seven HP 3235E extender frames


• Four isolated backplane analog buses for signal routing


• Two digital trigger buses for synchronization


• Quick Interconnect Fixture (QIF) for rapid reconfiguration of internal cabling


• HP-IB compatibility for remote instrument control


• Modular design allows configuration tailored to specific test requirements

Typical Applications The 3235A is the core platform for automated test systems requiring flexible signal switching, device characterization, and multi-parameter measurement. Its modular architecture supports applications ranging from component-level testing to complex system-level validation where reconfigurable signal routing is essential.

Compatibility & Integration The 3235A interfaces with HP-IB-compatible controllers and accepts industry-standard plug-in modules. Connection of multiple HP 3235E extender frames allows seamless scaling of system capacity without replacing the mainframe.