The NI PCIe-7841/7841R is a multifunction reconfigurable I/O device built around a user-programmable Xilinx Virtex-5 LX30 FPGA for high-speed control and data acquisition. It delivers onboard processing, direct I/O signal control, and flexible system timing synchronization across analog, digital, and clock domains. The device integrates 8 analog input channels, 8 analog output channels, and 96 bidirectional digital I/O lines, making it suitable for advanced research, machine control, and hardware-in-the-loop testing.
Technical Specifications
FPGA & Processing
• Xilinx Virtex-5 LX30
• 40 MHz clock rate
• 3 DMA channels
• 64 MB onboard memory
Analog Input
• 8 single-ended channels (DIFF, RSE, NRSE software-selectable)
• ±10 V input range
• 200 kS/s maximum sample rate
• 16-bit resolution
• 10 GΩ input impedance
• Dedicated ADC per channel for independent timing and triggering
• Overvoltage protection to +42 V
Analog Output
• 8 single-ended channels
• 1 MS/s maximum update rate
• 16-bit resolution
• 0.5 Ω output impedance
• 4 µs output conversion time
• 1 µs update time
• 10 V/µs slew rate
• Short-circuit protection to ground
Digital I/O
• 96 bidirectional channels
• TTL compatible; 3.3 V and 5 V logic levels
• 4.0 mA output current
• ±20 V input protection
• 25 ns minimum input pulse width
• 12.5 ns minimum output pulse width
• 5 ns minimum sampling period
• Programmable power-on state per line
• Overvoltage protection to +20 V
Interfaces & Physical
• PCI Express bus
• 3 × 68-pin female high-density VHDCI connectors
• 6.7 × 4.3 inches
• 0.28 lb
Environmental
• Operating: 0 °C to 40 °C, 10% to 90% RH non-condensing
• Storage: −20 °C to 70 °C, 5% to 95% RH non-condensing
– Key Features
• Independent ADC per analog input channel
• Programmable FPGA enables custom timing and synchronization logic
• High digital I/O channel count with nanosecond-precision pulse capability
• Configurable input/output protection thresholds
• Direct PCIe connectivity for high-throughput data transfer
– Typical Applications
• Custom control systems requiring deterministic timing
• High-speed data acquisition with onboard processing
• Hardware-in-the-loop simulation and testing
• Real-time signal processing and synchronization
– Compatibility & Integration
Programmable via LabVIEW FPGA Module. PCIe interface integrates into standard desktop and embedded computing systems.
