The Keysight/Agilent/HP 3235 Switch/Test Unit is a rack-mountable instrument for automated signal routing and testing. It delivers high-integrity switching across DC to 26.5 GHz with current handling to 10 Amps, serving as the control interface between test instrumentation and the device under test. The modular architecture accommodates up to 80 slots across a mainframe and seven extender frames, each with a 10-slot plug-in cage for switching and instrument modules. HP-IB compatibility enables computer control from multiple platforms. Four backplane analog buses isolate signal paths between modules and frames, while two trigger buses route digital control signals. Optional multimeter modules support signal measurement, and built-in self-test routines (DTEST, FTEST, FTEST SYS) verify switching path integrity and trigger bus operation. Quick Interconnect Fixtures streamline reconfiguration.
## Technical Specifications
• Frequency range: DC to 26.5 GHz
• Switching current: up to 10 Amps
• Mainframe slot count: 10 slots per mainframe (HP 3235)
• Extender frame slot count: 10 slots per extender (HP 3235E)
• Maximum expandable slots: 80 (one mainframe + seven extenders)
• Backplane analog buses: 4 isolated buses
• Trigger buses: 2 for digital signal routing
• Interface standard: HP-IB compatible
## Key Features
• Plug-in modular architecture for custom configurations
• High-integrity signal switching with path resistance measurement
• Fixtured self-test (DTEST) measures switching path resistance in ohms
• FTEST executes module self-tests and calibration via HP 34520 Multimeter
• FTEST SYS validates trigger bus system integrity
• Command-based programming with flexible syntax (space or comma separation)
• “3235 Ready” query confirms readiness for new commands
• Quick Interconnect Fixture for rapid cable management
## Typical Applications
• Automated test systems requiring multi-channel signal routing
• RF and microwave component characterization
• Multi-point analog and digital measurement networks
• Production test environments with expandable capacity
## Compatibility & Integration
HP-IB programming interface. Supports optional multimeter modules for integrated measurement. Compatible with HP 34520 Multimeter for module calibration.
