ADLINK PXI-2020/2022 Synchronous Acquisition Card Configuration and Synchronization Guide

ADLINK PXI-2020/2022 Multi Channel Synchronous Data Acquisition Card Application and Configuration Guide

In applications such as vibration analysis, multiphase power measurement, acoustic testing, and transient capture, the phase relationship between multi-channel signals is often equally important as the amplitude. Traditional DAQ cards that use multiplexer polling sampling introduce time skew between channels, resulting in phase information distortion. The ADLINK PXI-2020/2022 series synchronous sampling data acquisition card is designed for this purpose - the series provides 8-channel (PXI-2020) or 16 channel (PXI-2022) fully differential analog inputs, and all channels are sampled simultaneously by independent ADCs to ensure no phase delay between channels. Each channel has a resolution of 16 bits, a sampling rate of 250 kS/s, and is equipped with programmable gain (x 1/x 4), flexible digital triggering, 4 digital I/O channels, and 2 32-bit general-purpose timers/counters. It is suitable for scenarios such as automotive testing, transient measurement, ATE, and laboratory automation. The onboard 16K sample FIFO, combined with Scatter/Gather bus main control DMA, supports continuous high-speed data stream transmission. The PXI trigger bus and star trigger interface can achieve precise synchronization of multiple modules, while the onboard high-precision reference source (5.000V, temperature drift ± 3ppm/° C), combined with automatic calibration function, ensures long-term stability and measurement accuracy.

Product series positioning and key selection indicators

The PXI-2020/2022 series is positioned as a medium speed high-precision multi-channel synchronous sampling platform. Its core value lies in the fact that all channels share the same sampling clock, and each channel is equipped with an independent ADC and signal conditioning path, fundamentally eliminating the inherent inter channel crosstalk and sampling delay of the multiplexing architecture.

Model Differential Input Channel Number Resolution Maximum Sampling Rate (per channel) Gain Options Typical Applications

PXI-2020 8-channel 16 bit 250 kS/s x 1, x 4 medium channel number vibration/acoustics

PXI-2022 16 channel 16 bit 250 kS/s x 1, x 4 high channel number power/structure monitoring

The two models are completely identical in terms of PCB layout and electrical characteristics, except for the number of channels. PXI-2022 achieves 16 channel input through on-board analog switch multiplexing, but all channels still maintain synchronous sampling characteristics.

Performance core indicators (typical values at 25 ° C ± 5 ° C):

Offset error (gain x 1): ± 0.6 mV

Gain error (gain x 1): ± 0.02%

-3dB small signal bandwidth: 1 MHz at x 1, 700 kHz at x 4

System noise: 0.5 mVrms at x 1, 0.2 mVrms at x 4

CMRR（DC）：80 dB

SINAD: 82 dB, ENOB: 13.3 bits

SFDR：87 dB，THD：-85 dB

These indicators indicate that the series performs well in low noise and high dynamic range, making it suitable for high fidelity acquisition of weak signals (such as sensor outputs).

Key points for hardware installation and signal connection

2.1 Anti static and unboxing inspection

The board is a static sensitive device and must be operated on a grounded anti-static pad, wearing an anti-static wristband. The packaging contains board cards ADLINK All-in-One DVD、 Software installation guide and user manual. If damage is found, do not turn on the power.

2.2 PXI Plug and Play Configuration

The board complies with PXI specification Rev2.2 and supports 3.3V and 5V PCI signals. The system automatically assigns IRQ and I/O addresses without the need for manual jumper settings. If the system starts abnormally or experiences unstable operation, it is often due to interrupt conflicts. You can check the BIOS settings or replace the PXI slot.

2.3 Front panel SMA connector

The front panel of PXI-2020/2022 is equipped with 4 SMA coaxial connectors:

TRG IO: Bidirectional external digital trigger input/output port (3.3V LVTTL, 5V withstand voltage), minimum pulse width of 12.5 ns, polarity and edge software programmable.

CLK IN: External time base input (50 Ω AC coupling), input range 1-2 Vpp (sine or square wave), frequency 1-20 MHz, overvoltage protection 2.5 Vpp.

CLK OUT0/OUT1: Time base output (3.3V TTL, 50 Ω output impedance, driving capability 24mA), two outputs of the same source, used to synchronize other devices.

2.4 68 pin VHDCI connector and analog input connection strategy

All analog inputs, digital I/O, timers/counters, and auxiliary function signals are connected through a 68 pin VHDCI female socket. PXI-2020/2022 only supports differential input mode (no single ended option), with AIHx (positive terminal) and AILx (negative terminal) pins provided for each channel.

Grounding reference signal source (such as non isolated instrument output): The positive terminal is connected to AIHx, the negative terminal is connected to AILx, and the signal source ground can be connected to AGND (optional), using the common mode rejection capability of differential input to eliminate ground loop noise.

Floating signal source (such as thermocouple, transformer output): A bias resistor (approximately 100 times the source impedance) needs to be added between the negative input terminal (AILx) and AGND to provide a DC bias circuit for the instrument amplifier. If the source impedance is below 100 Ω, AILx can be directly short circuited to AGND.