NI PXI-6608 High-Precision Counter / Timer with Digital I/O

The NI PXI-6608 is a high-precision counter/timer module for PXI systems that delivers advanced timing, counting, and digital I/O capabilities in a single card. It combines eight 32-bit counters with a 10 MHz oven-controlled crystal oscillator, 32 lines of TTL/CMOS digital I/O, and three simultaneous DMA channels to support demanding measurement and control tasks across aerospace, automotive, industrial, and manufacturing test environments.

– Technical Specifications

Counter/Timer Channels
• Eight 32-bit up/down counters/timers
• Maximum source frequency: 80 MHz, or 125 MHz with prescalers
• Debouncing and glitch removal
• Duplicate count prevention and synchronous counting modes

Timebase
• 10 MHz oven-controlled crystal oscillator (OCXO)
• Oscillator stability: 75 ppb
• Five-minute warm-up time recommended for optimal specifications
• OCXO usable as counter GATE, SOURCE, or PXI backplane clock reference

Digital I/O
• 32 lines total: 8 dedicated + 24 shared with counter/timers
• TTL/CMOS compatible
• Input impedance: 25 kΩ to 500 kΩ
• Output impedance: 75 Ω
• Schmitt trigger hysteresis: 300 mV
• Digital debouncing filters
• Power-on state: input (high-Z) with pull-downs (10 μA to 200 μA)
• External supply at I/O connector: +4.65 V to +5.25 V, 1 A maximum

DMA
• Three simultaneous high-speed DMA channels

Power
• 5 VDC ±5%
• 1 A to 2.5 A (varies with application and OCXO warm-up)

– Key Features

• Encoder position measurement, event counting, period and pulse-width measurement
• Pulse generation and pulse-train generation
• Frequency measurement to 80 MHz (125 MHz with prescalers)
• Industrial ruggedness for harsh environments

– Typical Applications

Automotive and aerospace test, industrial motion control, manufacturing test, and synchronized multi-module PXI measurements.

– Compatibility & Integration

PXI bus interface with CompactPCI compatibility (PICMG 2.0 R3.0 core). Software: NI-DAQmx driver with LabVIEW, LabWindows/CVI, and Measurement Studio support.

Environmental
Operating: 0 °C to 55 °C, 0% to 90% non-condensing humidity. Storage: –20 °C to 70 °C, 5% to 95% non-condensing humidity.

Physical
16.0 × 10.0 cm form factor.