Astronics / EADS / Racal 2461-Cf Universal Counter Timer VXI Card

The Astronics / EADS / Racal 2461-CF is a C-size VXIbus Universal Counter Timer card engineered for precision timing and frequency measurements in automated test equipment and data acquisition systems. This module delivers comprehensive measurement capabilities including frequency, period, time interval, pulse width, rise/fall time, and phase analysis. The CF designation denotes an Oven Controlled Crystal Oscillator (OCXO) timebase, providing exceptional stability for demanding metrology applications.

Technical Specifications Measurement Performance

Frequency range: 0.01 Hz to 200 MHz with 9-digit resolution

Time interval resolution: 1 ns (single shot), 100 ps (averaged mode)

Time interval range: 100 ns to 1000 s

Trigger resolution: 2.5 mV

Input impedance: 1 MΩ // 20 pF (AC/DC coupled, selectable)

Maximum input voltage: 5 Vrms

Selectable 50 kHz low-pass filter per channel Timebase Stability (OCXO)

Aging: ±1 ppm/day, ±1 × 10⁻⁷/yr

Temperature stability: ±1 × 10⁻⁷ (0°C to 50°C)

Adjustment range: ±2 × 10⁻⁶

Warm-up: ±1 × 10⁻⁶ in 45 s, ±1 × 10⁻⁷ in 3 minutes Physical & Environmental

Form factor: C-size VXI module (8.75″ W × 2.625″ H × 12.5″ D)

Weight: 8.5 lbs

Operating temperature: 0°C to 50°C

Storage temperature: -40°C to 70°C

Key Features

Dual-channel configuration (standard)

Frequency, period, time interval delay, and totalize measurements

Rise time, fall time, positive/negative pulse width analysis

Frequency ratio and phase measurements (channel-to-channel)

Peak detection (positive, negative, mid-range)

DC voltage measurement capability (MAX, MIN, DC values)

Nine arming modes via external input and VXI TTL trigger lines

Continuous, single-shot, and external trigger modes

Typical Applications

Frequency and timing validation in production test systems

Precision phase measurement in communications test

Pulse characterization and waveform analysis

Time-interval and jitter measurement in digital systems

Multi-channel synchronized measurement in automated test environments

Compatibility & Integration Designed for integration into C-size VXIbus chassis systems. Compatible with VXIbus standard interfaces and modular test architectures supporting up to 3 function cards per C-size slot configuration.