Detailed Specifications of NI PXI-6602 Timing and Counter Module
The NI PXI-6602 is a high-precision timing and counter/timer module engineered for PXI hybrid bus architectures. Distinguished by its 8 independent 32-bit counters and 32-channel digital I/O, it specializes in deterministic timing tasks such as encoder position tracking, high-frequency measurement, and synchronized pulse generation. Equipped with RTSI synchronization bus support and digital debouncing filters, it is ideal for industrial automation, aerospace testing, and high-speed control systems requiring sub-microsecond timing accuracy.
1. Basic Information
- Module Series: PXI Timing and I/O Module, optimized for hybrid PXI systems
- Part Number: 777941-01 (standard model)
- Physical Dimensions: 1-slot 3U PXI form factor, 10cm × 16cm (width × length)
- Weight: Approximately 5.3 ounces (0.15kg)
- Interface Type: 68-pin male SCSI-II connector, supporting compact signal routing
- Operating Temperature Range: 0°C ~ 55°C (commercial grade)
- Shock Resistance: 50g peak (11ms duration)
- Vibration Resistance: 2g RMS (10Hz ~ 500Hz)
- Isolation Type: Non-isolated (signal paths share common ground)
- Compliance: RoHS non-compliant; meets FCC Part 15 Class A and CE EN 61326-1 standards
2. Core Technical Specifications
2.1 Counter/Timer Subsystem
- Configuration: 8 independent 32-bit up/down counters, supporting simultaneous multi-task execution
- Internal: 100kHz, 20MHz, 80MHz (base frequency)
- External: Up to 80MHz (via front-panel input)
- Extended Range: 125MHz (with software prescaling)
- Timebase Stability: ±50 ppm (typical), ensuring long-term timing consistency
- Event Counting: Rising/falling edge detection, up to 80MHz input frequency
- Frequency Measurement: 0.1Hz ~ 10MHz, resolution down to 1mHz
- Period/Pulse Width Measurement: Minimum 100ns resolution
- Pulse Generation: Custom duty cycle (0.1% ~ 99.9%), frequency up to 40MHz
- Encoder Decoding: Supports quadrature (A/B) and index pulse decoding for position tracking
- Buffered Operations: Hardware FIFO buffer (4096 samples) per counter, enabling burst-mode data capture without CPU intervention
- Debouncing Filters: Programmable digital glitch removal (10ns ~ 1ms), eliminating noise from mechanical switches
2.2 Digital I/O Interface
- Channel Configuration: 32 bidirectional TTL/CMOS-compatible lines
- 8 dedicated digital I/O lines
- 24 lines shared with counter/timer signals (configurable via software)
- Input: -0.3V ~ 5V (TTL-compatible)
- Output: 0V ~ 5V (TTL-compatible)
- Drive Capability: 4mA source/sink current per channel, sufficient for logic-level signaling
- Input Filters: Programmable debouncing (10ns ~ 1ms) to suppress electrical noise
- Configuration Flexibility: Software-defined input/output direction per channel; no programmable power-up states
2.3 Synchronization and Triggering
- Synchronization Bus: Integrated RTSI bus interface, enabling clock/trigger sharing with other PXI modules (e.g., DAQ, oscilloscope modules)
- Digital Edge Trigger: Rising/falling edge on any digital I/O or counter output
- Software Trigger: API-initiated trigger for automated test sequences
- External Trigger: TTL-compatible signal via front-panel connector
- Multi-Module Sync: Distributes 80MHz timebase via RTSI bus for phase-coherent operation across multiple PXI-6602 units
- DMA Support: 3 independent high-speed DMA channels for simultaneous counter and digital I/O data transfer, reducing latency to <10μs
3. Software and Driver Support
- Recommended Drivers: NI-DAQmx 8.0 and above; NI-DAQmx Base compatible for cross-platform use
- Programming Compatibility:
- NI Ecosystem: LabVIEW (8.0+), LabWindows/CVI (8.0+), Measurement Studio (7.1+)
- Third-Party Languages: C/C++, C#, Python (via pyDAQmx), MATLAB (via Data Acquisition Toolbox)
- Real-Time Support: Compatible with NI VeriStand and LabVIEW Real-Time for deterministic control
- Configuration Tools: NI Measurement & Automation Explorer (MAX) for graphical counter routing and I/O channel mapping
- Diagnostic Features: Counter overflow detection, DMA transfer verification, and digital line status monitoring via driver APIs
4. Typical Application Scenarios
The NI PXI-6602 excels in timing-critical applications requiring multi-channel synchronization:
- Industrial Automation: Quadrature encoder position tracking for robotic arms; pulse-width modulation (PWM) control of motor drives
- Aerospace Testing: Synchronized trigger generation for 6+ PXI-5112 oscilloscope modules in explosive event testing ; rocket engine valve timing verification
- Power Electronics: Frequency measurement of grid signals; inrush current pulse counting for circuit breaker testing
- Automotive Validation: ABS sensor signal decoding; ignition timing pulse generation for engine test benches
- Laboratory Research: Precision time-interval measurement for particle detectors; multi-channel event counting in physics experiments
5. Selection and Compatibility Notes
- Ideal Use Cases: Applications requiring 8+ independent counters, TTL digital I/O, and RTSI synchronization (e.g., multi-sensor data acquisition systems)
- Chassis Compatibility: Works with all NI 3U PXI chassis (e.g., PXIe-1075, PXI-1042) and third-party PXI hybrid chassis
- Sync with DAQ Modules: PXI-6259 (analog I/O) and PXI-5112 (oscilloscope) via RTSI bus
- Signal Conditioning: Pair with SCXI-1162 for high-voltage digital input protection (up to 30V)
- Limitations: Non-isolated design (avoid use in high-voltage environments >5V); limited to TTL logic levels
- Higher Isolation: NI PXI-6614 (250Vrms isolated counters)
- More Channels: NI PXI-6682 (16 counters, 100MHz timebase)
- PCI Form Factor: NI PCI-6602 (identical functionality for desktop systems)
