The Racal Instruments 2461-CF-CS247 is a VXIbus-based universal counter-timer module delivering comprehensive signal measurement and analysis capabilities in a modular C-size form factor. This dual-channel instrument performs frequency, period, time interval, rise/fall time, pulse width, phase, and ratio measurements across a 0.01 Hz to 100 MHz range, with optional 1.3 GHz capability. It integrates DVM functions for voltage measurement and supports up to 14,000 readings in onboard memory.
Technical Specifications
• Model: Racal Dana 2461CF (Part Number: 2461-CF-CS247)
• Form Factor: VXIbus C-size module, single slot
• Measurement Functions: Frequency, period, time interval, time interval delay, rise time, fall time, pulse width, frequency ratio, totalize, phase measurement, DVM (max/min/DC voltages)
• Frequency Range: 0.01 Hz to 100 MHz (Option 41: to 1.3 GHz)
• Frequency Resolution: Up to 10 digits per second
• Time Interval Resolution: 1 ns (single shot); 100 ps (average mode)
• Time Interval Measurement Range: 100 ns to 1000 s
• Input Impedance: 1 MΩ // 20 pF
• Maximum Input Voltage: 5 Vrms
• Dynamic Range (x1 Attenuation): < 50 MHz (5 V pk-pk min); < 100 MHz (2.5 V pk-pk min); < 200 MHz (1.5 V pk-pk min)
• Dynamic Range (x10 Attenuation): < 50 MHz (50 V pk-pk min); < 100 MHz (25 V pk-pk min); < 200 MHz (15 V pk-pk min)
• Gate Times: 100 ms, 1 s, 10 s, 100 s, 1 ks, 10 ks, 100 ks
• Timebase Stability: ±1 ppm (TCXO standard with ±1 × 10⁻⁶ per year aging; OCXO option available)
• Measurement Timeout: 1 to 10⁵ s (programmable)
• Memory: Up to 14,000 readings
• Channels: 2 (4-channel configurations available)
• Trigger Modes: Continuous, single, external
• Power Supply: 100-240 VAC, 50/60 Hz
– Key Features
• Selectable timebase: VXI CLK 10 or external 10 MHz input (100 mV min, 1 kΩ nominal impedance, AC coupled)
• Per-channel low-pass filtering with hysteresis
• Automatic pulse characterization (rise time, fall time, pulse width)
• Programmable arming via front panel or VXI TTL Trig 0-7
• Time error correction for high-speed measurements
– Typical Applications
Telecommunications testing, aerospace signal analysis, research laboratory measurements requiring modular VXI integration.
– Compatibility & Integration
VXIbus protocol compliant. Operates within standard VXI chassis environments with configurable external timebase reference.
