ADLINK PCI-9112 Multi functional Data Acquisition Card

Deep technical analysis and engineering application of ADLINK PCI-9112/cPCI-9112 multifunctional data acquisition card

Introduction: The enduring value of classic multifunctional DAQ in testing and measurement

In the field of testing and measurement, multifunctional data acquisition with high integration can meet various needs such as analog input, analog output, digital I/O, and counting/timing with a single board solution, thereby reducing system complexity and cost. The Linghua PCI-9112 series is a model of such products, widely used in laboratory automation, production line testing, environmental monitoring, and teaching experiments since its launch.

The core competitiveness of this card lies in its flexible signal conditioning capability: 16 single ended or 8 differential analog inputs, combined with 4 levels of programmable gains (× 0.5, × 1, × 2, × 4, × 8), can cover a wide dynamic range from ± 10V to ± 0.625V (bipolar) and from 0~10V to 0~1.25V (unipolar). Although the sampling rate of 110 kS/s is not top-notch, it is more than sufficient for most sensor signals (temperature, pressure, vibration, displacement, etc.). In addition, it supports bus master DMA, ensuring efficient data transfer on Windows or Linux systems and reducing CPU burden.

This article will analyze the hardware design, interface definition, software support, and system integration points of the card layer by layer, providing engineers with a complete technical reference manual.

Analog input front-end: channel configuration and gain programming

2.1 Channel Mode

Single ended mode (SE): Provides 16 analog input channels (AI0~AI15), each measuring relative to the common ground (AGND). Suitable for scenarios where the signal source and acquisition card are grounded together without severe common mode noise.

Differential Mode (DIFF): Provides 8 differential channels (AIH0/AIL0~AIH7/AIL7), each pair of differential inputs can effectively suppress common mode interference, suitable for long-distance transmission or sensors with ground potential difference (such as thermocouples and strain gauges).

Mode selection is controlled through software configuration (register control), without the need for hardware jumpers, providing high flexibility.

2.2 Input Range and Gain

The combination of gain and range is shown in the following table (excerpted from the manual):

Gain bipolar range unipolar range

0.5 ±10V —

1 ±5V 0~10V

2 ±2.5V 0~5V

4 ±1.25V 0~2.5V

8 ±0.625V 0~1.25V

The gain of each channel can be independently programmed (through a channel gain queue), allowing signals of different ranges to be mixed in the same scanning sequence. For example, channel 0 measures ± 10V pressure sensor, channel 1 measures ± 1.25V thermocouple, and channel 2 measures 0-5V flowmeter, all of which can be collected simultaneously.

2.3 Accuracy indicators

Gain 0.5, 1: Accuracy of ± 0.01% FSR ± 1 LSB.

Gain 2 and 4: Accuracy of ± 0.02% FSR ± 1 LSB.

Gain 8: Accuracy of ± 0.04% FSR ± 1 LSB.

The minimum voltage resolution corresponding to a 12 bit resolution in the ± 10V range is about 4.88mV; in the ± 0.625V range, it is about 0.305mV. The small signal measurement accuracy is effectively improved through gain amplification.

2.4 Input Characteristics

Input impedance: 1 G Ω (high impedance), with minimal load on the signal source.

Overvoltage protection: Continuous ± 35V, can prevent accidental connection of high voltage and damage to equipment.

Coupling method: DC coupling, suitable for all low-frequency to mid frequency signals.

2.5 Data collection triggering and transmission

Trigger mode: software triggered (only supports software triggering, no external hardware triggering).

Data transmission: Supports programmable I/O, interrupts, and bus master DMA. In DMA mode, data is directly written from the board to the system memory through the PCI bus, without the need for CPU intervention, significantly improving throughput and reducing CPU usage.

Analog output: dual channel waveform generation capability

PCI-9112 provides two 12 bit analog output channels (DA0, DA1), suitable for generating excitation signals, controlling actuators, or serving as voltage references.

3.1 Output Range (Software Programmable)

Monopolar: 0~10V, 0~5V, 0~EXTREF (external reference voltage).

Bipolar: Not explicitly listed, but depending on the model suffix (PCI-9112 calibrated at 5V, PCI-9112A calibrated at 10V), it may support ± 5V or ± 10V (please refer to the detailed manual). This data manual only lists the range of unipolar polarity, and bipolar polarity needs to be combined with external references or set through jumper wires.

3.2 Performance Parameters

Resolution: 12 bits.

Establishment time: 30 μ s to ± 0.5 LSB.

Drive capability: ± 5 mA (maximum), can directly drive simple loads.

Data transmission: Programmable I/O (writing to output registers).

3.3 Calibration Options

PCI-9112: Analog output calibrated in 5V range.

PCI-9112A: Analog output calibrated in 10V range.

Users can choose the appropriate model based on the application to avoid accuracy loss caused by mismatched calibration ranges.

Digital I/O and Timer/Counter

4.1 Digital I/O

16 digital inputs+16 digital outputs, TTL level (5V compatible).