ADLINK PCI-9114 (A) Data Acquisition Card Selection and Configuration Guide

ADLINK PCI-9114 (A) Data Acquisition Card Selection and Configuration Guide

Introduction: The core position of high-precision data acquisition in testing and measurement

High resolution, multi-channel synchronous data acquisition is the cornerstone of accurate measurement in applications such as industrial process monitoring, medical instruments, vibration analysis, and power monitoring. The ADLINK PCI-9114 (A) series is a 16 bit multifunctional data acquisition card based on a 32-bit PCI bus, providing up to 250kHz sampling rate, 32 single ended/16 differential inputs, programmable gain amplification, 1K word FIFO buffer, and 16 isolated digital I/O. With flexible interrupt and trigger mechanisms, it can handle various scenarios from slow temperature acquisition to high-speed dynamic signal analysis. This article will systematically review the differences between PCI-9114 and PCI-9114A, the selection of gain versions (DG/HG), analog input configuration, triggering and data transmission modes, isolation DIO characteristics, and calibration methods, providing engineers with a complete engineering deployment reference.

Model comparison and selection criteria

The PCI-9114 series includes two speed versions and two gain versions, with the following key differences:

Model highest sampling rate gain option (DG) gain option (HG) pre triggered independent counter

PCI-9114 Rev.B1 100kHz 1/2/4/8 1/10/100/1000 None None

PCI-9114 Rev.C2 100kHz 1/2/4/8 1/10/100/1000 available

PCI-9114A 250kHz 1/2/4/8 1/10/100/1000 available

Key selection points:

Speed priority: PCI-9114A provides a 250kHz single channel sampling rate, suitable for high-speed signals such as vibration analysis and acoustic measurement.

Weak signal detection: The HG version provides a maximum gain of 1000 times and can fully utilize a 16 bit resolution (theoretical resolution of about 0.3 μ V) for ± 10mV signals, making it suitable for low-level sensors such as thermocouples and strain gauges.

Pre trigger function: PCI-9114A and Rev.C2 support Pre Trigger, which can collect specified points before and after external trigger signals, suitable for impact testing or fault recording.

Independent Counter: The new version provides a user configurable 8254 Counter # 0, which can be used for frequency measurement or pulse generation.

Analog input configuration and signal connection

3.1 Single ended and differential input selection (JP1)

PCI-9114 (A) supports 32 single ended (SE) or 16 differential (DI) inputs, selected through JP1 jumper:

Single ended mode: All signals are relative to analog ground (AGND), suitable for floating signal sources or short distance transmission (<3m). The maximum number of channels (32), but the ability to resist common mode interference is weak.

Differential mode: Each channel uses a pair of signal lines (AIxH/AIxL) to measure the difference between the two. It can effectively counteract common mode noise and is suitable for long-distance transmission or scenarios with ground potential differences. Reduce the number of channels by half (16 channels).

Engineering suggestion: If the signal source is grounded or there is significant common mode noise (such as in a frequency converter environment), differential mode should be prioritized; If it is a floating signal (such as a thermocouple), single ended mode can be used with cold end compensation.

3.2 Gain and Input Range

The analog input of PCI-9114 (A) is bipolar and does not support unipolar. Corresponding relationship between gain and range:

DG version: 1 →± 10V, 2 →± 5V, 4 →± 2.5V, 8 →± 1.25V

HG version: 1 →± 10V, 10 →± 1V, 100 →± 100mV, 1000 →± 10mV

When selecting gain, it is necessary to ensure that the signal peak does not exceed the range, otherwise saturation clipping may occur. At the same time, try to make the signal occupy more than 80% of the full range to fully utilize the 16 bit resolution.

3.3 Cold end compensation (JP2)

When directly connected using a thermocouple, the onboard cold junction compensation sensor (C.J. Sensor) can be enabled through JP2 and routed to AD channel # 0 or # 16 (depending on single ended/differential mode). The conversion relationship for the calibrated cold junction voltage is: V (mV)=T (K) × 10 (mV/K). After activation, the temperature values measured by the software already include cold end compensation and do not require external reference.

Trigger source and data collection mode

PCI-9114 (A) provides three types of A/D trigger sources:

4.1 Software Trigger (TSSEL=0)

Writing any value to the software trigger register initiates a single conversion. Suitable for low-speed, non periodic data collection (such as manual recording). The completion of the conversion can be determined by polling the AD_SUSY or FF_SF flag.

4.2 Timer Trigger (TSSEL=1)

Using onboard 8254 counters # 1 and # 2 cascaded to generate precise timing pulses, driving A/D conversion. The maximum triggering frequency is limited by the sampling rate (250kHz for PCI-9114A and 100kHz for PCI-9114). By setting the frequency division coefficient through _9114A_Timer (c1, c2), the actual frequency is 2MHz/(c1 × c2).

Engineering note: When the sampling rate of PCI-9114 is 100kHz, it is recommended that c1 × c2 ≥ 20 (2MHz/100kHz); If the trigger frequency is set too high (>maximum sampling rate), the FIFO will overflow and data will be lost.