104-AIO12-8 Multifunction Analog I/O Board

PC/104 Analog I/O Board


  • Eight true differential inputs, or eight single-ended inputs optional
  • Programmable input ranges of: 0-5V, 0-10V, ±5V, ±10V
  • 100KHz sampling rate
  • On-board pacer clock and counter timers
  • Four double-buffered analog outputs
  • Jumper selectable output ranges of: 0-5V, 0-10V, ±5V, ±10V
  • 24 digital I/O lines, type 82C55 with change of state detect on port C, buffers on ports A & B
  • Flexible configurations to suit your needs

Factory Options: (call for pricing and availability)

  • 4-20mA inputs with offset
  • Channel by channel pre-amplifier gains of 1-100
  • +5VDC only operation
  • 0 to +70°C and -40 to +85°C versions available
  • RoHS Available. Please contact us for ordering information
Last updated on November 2, 2023, 6:22 pm


In Stock



The following functions are available in many configurations giving the user the ability to specify exactly what’s needed. Interrupts are individually or globally enabled or disabled via software. A status register is provided to determine the interrupt source.


The Analog Inputs feature software programmable gain with ranges of 0-5V, 0-10V, ±5V, and ±10V. The configuration employs an instrumentation pre-amplifier per channel which allows for differential inputs, 200V Common Mode Rejection, high input impedance, and optional factory channel by channel pre-settable gain (1-200) to accommodate low-level inputs from sensors. Inputs 4-20mA are available as a factory-installable option.


Output ranges of 0-5V, 0-10V, ±5V and ±10V, are field selectable with jumpers. Note that four conversions may take place at once and that, since the D/As are double buffered, data for the next conversion may be loaded simultaneously.


The circuit uses an 82C54 (3 sixteen bit counter/timers). The user has access to each counter/timer’s gate, clock, and output signals. The output of counter two can be used to generate an interrupt. The software package supports counting events, frequency output, pulse and frequency measurement.


The circuit uses an 82C55A PPI with mode 0 supported. Ports A and B (16 lines) are buffered and pulled up to 5V. Port C features Change of State detection.


The package includes a graphical Windows setup program detailing all jumper settings. Also included are drivers, samples and utilities for DOS, Windows operating systems (XP -> 10, both 32 & 64 bit), and Linux. Full register-level support for use in custom real-time or embedded operating systems.


Data Sheets



Drivers and Downloads

Full list of available Downloads: Software Packages, Drivers, Manuals, and other documents

Information about our Free Software packages:

ACCES is proud to provide a full suite of software support with every Data Acquisition product. We are committed to supporting the most popular operating systems and platforms for our customers. Currently we are actively supporting XP -> 10, both 32 & 64 bit, including “Server 2008,” “Embedded,” and “Compact” flavors for all plug-and-play products including PCI, PCI Express, USB, and more. Many products continue to ship with support for additional operating systems such as DOS, Windows 95, 98, Me, NT4, and 2000.


Among the software we deliver with our products are sample programs in a wide variety of programming languages. These samples are used to demonstrate the software interfaces to our products — and many can be used as-is in your production environments, or to test functionality of the devices out-of-the-box. We’re currently actively supporting sample programs in Microsoft Visual C#, Visual Basic, Delphi, and Visual C/C++, with many devices including samples in Borland C/C++ 3.1 for DOS. Additionally we provide National Instruments LabVIEW compatible DLLs and many demonstration VIs for our devices.


Drivers for various operating systems are also provided, including active support for Windows XP -> 10 — all in both 32-bit and 64-bit flavors, and including consumer, server, and embedded varieties — as well as the 2.6 and newer Linux kernels and recent OSX / macOS versions. Many products continue to ship with driver support for Windows 95, 98, Me, NT4, and Windows 2000, but support for these operating systems is considered deprecated.

Setup Programs and Utilites

Our Data Acquisition devices also include a graphical setup utility that walks you through the process of configuring any option jumpers or switches on the device, as well as explaining a little about the various connectors present.

Many devices also include utility programs – little tools to make your use of the device easier, such as EWriter, a program that allows you to read and write data in the user-accessible EEPROM locations on all our USB data acquisitition products; or WinRISC, a “Really Incredibly Simple Communications” terminal program that lets you get started instantly with serial devices.

“Register Level” Documentation

Besides all this software in all these languages and operating systems ACCES has a policy of open and transparent development: none of our lowest-level “register” interfaces are hidden from you — we document every register in every bus card, every command in every serial board, and every usb control transfer in every USB Data Acquisition board. These lowest-level interfaces allow you to develop for our products in ANY operating system or language, regardless of our actively supporting it or having a driver for it. We have customers actively developing in ADA, Android, Python, Java, MATLAB, Solaris, and more, just by referring to our complete low-level interface documentation! And we provide the full source code to all of our drivers, regardless of operating system, to give you an even bigger head start in your own development tasks.

No Fees or Royalties

All of this software is provided at no additional charge, and is licensed under any of a variety of flexible — and royalty free — options. Check out our software license explanation if you’d like more information.

non-plug-and-play driver install guide for Windows

Please refer to the Non-PnP Install Guide for instructions to get your PC/104 and ISA bus devices installed in modern Windows.

Custom Software

ACCES also offers Custom Software Services for our products. Our prices are unbelievably low, often as inexpensive as free! If you need something tweaked to support your needs, or an entire enterprise application developed from scratch, it is definitely worth your time to inquire with us, first.

Further information about available ACCES Software:

Redistributing Windows Drivers
A list of ACCES drivers and the files that compose them under different versions of Windows, so you can easily redistribute ACCES cards and drivers.

Analog Inputs

  • No. of Channels: Eight true differential inputs, or eight single-ended inputs optional
  • Programmable Ranges: 0-5V, 0-10V, ±5V, ±10V, (4-20mA as a factory option)
  • Conversion Frequency: 100K Samples per Second
  • Resolution: 12-Bit
  • Differential Input Impedance: 2Meg Ohms w/pre-amp
  • Preamplifier gain: 1 standard, Optional gains up to 200 upon request
  • Reference Output Voltage: 4.096V ±0.02V
  • Common Mode Voltage: ±200V
  • Common Mode Rejection Ratio: 86dB typical
  • Integral Nonlinearity: 1 LSB maximum, Monotonic
  • Full Power-Down Mode: 1µA maximum
  • Standby Power-Down Mode: 400µA maximum
  • Accuracy: 0.2% of full scale
  • Gain Temperature Coefficient: 6 ppm / °C typical, bipolar; 8ppm/ °C typical, unipolar
  • Noise levels: ±1 LSB typical
  • A/D triggering method: Software selectable: programmable timer, program command

Analog Outputs

  • Channels: 4
  • Voltage Ranges: 0-5V, 0-10V, ±5V, ±10V
  • Conversion Frequency: 100K Conversions per second
  • Resolution 12-Bit
  • Output Drive Capability: 3 mA per channel
  • Power-Down Mode Current Draw: 1µA, maximum
  • Relative Accuracy: ±2 LSB, typical
  • Trigger Source(s): Software selectable: programmable timer, program command

Digital Inputs/Outputs

  • Programmable Peripheral Int.: 82C55A
  • Channels: 24, pulled up to 5V via 10K (or pulled down to ground factory option)
  • Buffered Channels: 16 (ports A & B)
  • Input Voltage: Logic low: -0.03V min, 0.8V max;
  • Logic High: 2.2V min, 5.8V max
  • Input Current: ±1uA Max
  • Output Voltage:
    • Logic low: 0.0V min, 0.4V max
    • Logic High: 3.7V min, 5.0V max
  • Output Current:
    • Ports A and B
      • Logic low: 64mA Sink
      • Logic High: 32mA Source
    • Port C
      • Logic low: 2.5mA Sink
      • Logic High: 2.5mA Source
  • Modes supported: Mode 0 (1 and 2 are factory options)
  • Change of State Detection 8 inputs (port C)


  • Peripheral Interface Timer: Type 82C54
  • Counters 3 x 16-Bit down counters
  • Clock Frequency Output: 1Mhz
  • Inputs/Outputs Fully Buffered
  • Native Modes: Pulse on terminal count, retriggerable one-shot, rate generator, square wave, software triggered strobe, hardware triggered strobe.
  • Software Support: Event Counter, Frequency Output, Frequency and Pulse Measurement


  • Power Required (using ±12V and +5V):
    • +12VDC: 30 mA typical
    • -12VDC: 30 mA typical
    • +5VDC: 40 mA typical
  • Power Required (using only +5V, with the optional DC/DC Converter):
    • +5VDC: 240 mA
  • Environmental: 0°C to +70°C standard, optional -40°C to +85°C
  • Interrupt Requests: Eleven channels, IRQ 3-7, 9-12, 14, 15
  • Interrupt Status Register: Indicates source(s) of interrupt
  • Interrupt Enable/Disable: Software Controlled

CE testing & approval must be done at the system level, in the designed enclosure, and is not done on individual boards.

ModelDescriptionPrice (USD)

PC/104 Multifunction 12-Bit, 8-Channel Analog Input Board


PC/104 Multifunction 12-Bit, 8-Channel Analog Input, 4 Analog Output Board

C104-34F-12 Cable, Ribbon, F-F Headers, 34 pin, 12″ $12
C104-50F-12 Cable, Ribbon, F-F Headers, 50pin, 12″ $15
Terminal Boards
STB-34 34-pin screw terminal board $44
STB-50 50-pin screw terminal board $44
Model Options (call for pricing)
-DC DC/DC Converter to operate on 5V only
-I 4-20mA inputs
-T Extended operating temperature (-40°C to +85°C)