Racal Instruments 1261-S / 70-0050-000

The Racal Instruments 1261-S (70-0050-000) is a VXI mainframe chassis engineered for precision signal generation and analysis in demanding test environments. This unit delivers high dynamic current capability and low-ripple power to support crisp waveforms and accurate measurements across modular instrument configurations. The 1261-S combines fault-tolerant cooling, advanced power distribution, and optional system monitoring to ensure reliable operation in rack and benchtop deployments.

– Technical Specifications

Chassis Architecture
• VXI Mainframe with 13-slot configuration
• Available in 7U and 9U form factors
• Independent power supply assembly (non-slot consuming)

Power Delivery
• Total usable power: 500W to 1000W depending on model variant
• Direct backplane integration for optimal power distribution
• High dynamic current capability
• All voltage rails protected against over-voltage, under-voltage, over-current, under-current, over-temperature, short to ground, and inter-rail shorts
• Minimal ripple and noise on all outputs

Cooling System
• Fault-tolerant design with three rear-pluggable fans
• Operation maintained if single fan fails
• Pressurized plenum system for uniform airflow distribution
• Molded card guides direct airflow through installed modules
• HI/LO cooling switch on standard units for noise/performance trade-off
• Variable-speed cooling available with Enhanced Monitoring System (EMS) — fan speed adjusts based on highest slot temperature rise

Monitoring and Diagnostics
• Standard Monitoring System (SMS): VXIbus voltage, current, airflow, and temperature monitoring with bi-color LED status annunciators; independent power rail
• Enhanced Monitoring System (EMS): Microcontroller-based VXIbus-compliant interface with front panel alphanumeric display and soft front panel reporting via backplane commands

– Key Features

• Fault-tolerant cooling maintains operation during single-fan failure
• Advanced power supply minimizes ripple and noise for signal integrity
• Comprehensive protection on all voltage rails
• Flexible deployment options: rack mount and benchtop configurations
• Optional system monitoring provides real-time mainframe diagnostics

– Typical Applications

• Multi-module test instrument systems
• Signal generation and analysis platforms
• High-reliability automated test equipment (ATE)
• Precision measurement systems requiring low-noise power delivery

– Compatibility & Integration

VXI-compliant modular architecture accepts industry-standard VXI instruments. Optional EMS supports VXIbus message-based status reporting and soft front panel integration.