NI PXI-6255 16-Bit Multifunction DAQ Module

The NI PXI-6255 is a 16-bit multifunction data acquisition module designed for PXI systems. It integrates 40 differential or 80 single-ended analog input channels, 2 analog output channels, 24 digital I/O lines, and 2 counter/timer circuits into a single compact device. Built for high-performance measurement and control applications, the PXI-6255 delivers 1.25 MS/s single-channel sampling on analog inputs with 750 kS/s aggregate multichannel performance. Its 7 programmable input ranges—from ±0.1 V to ±10 V—provide precision across diverse signal scales.

– Technical Specifications

Analog Input
• 40 differential or 80 single-ended channels
• 16-bit resolution
• 1.25 MS/s single-channel maximum; 750 kS/s aggregate multichannel
• Input ranges: ±0.1 V, ±0.2 V, ±0.5 V, ±1 V, ±2 V, ±5 V, ±10 V
• Maximum working voltage: ±11 V referenced to AI GND
• CMRR: 100 dB (DC to 60 Hz)
• Input bias current: ±100 pA
• Small signal bandwidth (−3 dB): 1.7 MHz
• Input FIFO: 4,095 samples
• Scan list memory: 4,095 entries

Analog Output
• 2 channels, 16-bit resolution
• Sampling rate: Up to 2.86 MS/s
• Output impedance: 0.2 Ω
• DC-coupled

Digital I/O
• 24 total lines: 8 in P0 port, 16 in P1/P2 ports
• Individually programmable as input or output
• Correlated digital I/O: 8 channels at 10 MHz maximum
• Pull-down resistor: 50 kΩ typical
• Voltage protection: ±25 V (device on), ±15 V (device off) on up to four AI pins; ±20 V on digital channels

Counters/Timers
• 2 counters, 32-bit resolution
• 80 MHz frequency

Triggering & Synchronization
• 1 analog trigger supporting sample clock, start, pause, convert, and reference modes
• Digital trigger support via PFI, RTSI, PXI_TRIG, and PXI_STAR sources
• Software-selectable polarity

– Key Features

• Dual 68-pin VHDCI connectors for flexible I/O routing
• RTSI trigger bus integration for multi-device synchronization
• Environmental operation: 10% RH to 90% RH non-condensing
• High channel density with flexible input coupling and range selection

– Typical Applications

• Laboratory automation and design verification
• Manufacturing test and measurement systems
• Research data acquisition in demanding environments

– Compatibility & Integration

The PXI-6255 integrates into standard PXI chassis and works with NI signal conditioning platforms. RTSI busing enables deterministic multi-device triggering for coordinated measurements across distributed instrumentation.