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PC/104 Digital Quadrature Encoder Input Board


  • 4, 6, or 8 channels of quadrature encoder inputs and channel index inputs
  • Counts outputs from eight quadrature encoders
  • Three differential channels per encoder, including dual axis and index
  • Input ranges: ±25V and ±7V common mode
  • 4.3MHz maximum clock rate
  • Individual software reset for each channel
  • Standard counting and alarm functions
  • Programmable for counting, speed, and direction; limit setting with with interrupts
  • Factory flexible interrupt options
  • RoHS Available. Please contact us for ordering information


  • Automatic Test Systems
  • Laboratory Automation
  • Robotics
  • Machine Control
  • Security Systems, Energy Management

The 104-QUAD-8 card is a general purpose Quadrature Encoder Counter/Interface board. It is provided in the popular 104 format and conditions and monitors the outputs of 8 encoders.

These functions include anything that can be programmed into the versatile LSI/CSI LS7266R1 integrated circuit. These functions include speed, direction and total count. By providing these functions, it frees the computer for higher level applications.

The ability to provide an interrupt for a parameter, such as total count, further frees the computer from the necessity of constantly reading the position of an encoder.

Interrupts are directed to levels #2 through #7, #10 through #12, and #15 by jumper installation.

The 104-QUAD-8 card is designed for industrial applications. Each input line is buffered and capable of utilizing inputs up to 25 volts. A 5 Volt source is available for appropriate encoders.

The conditioned inputs are connected to appropriate LSI/CSI LS7266R1 integrated circuits. These circuits are the heart of the card's operation. They may be programmed for a variety of functions.

The 104-QUAD-8 occupies 32 bytes of I/O address space. The base address is selectable via jumpers anywhere within the range of 100-3E0 hex. An illustrated setup program is provided with the 104-QUAD-8 card. Interactive displays show locations and proper settings of jumpers to set up board address and interrupt levels.


The one language not recommended for programming interrupt service routines is any version of Visual BASIC. The recommended programming languages for IRQ based applications are Delphi and C Builder.


Power Consumption

  • 5 Volts: 260mA


  • Receiver Type: AM26LS32
  • Configuration: Each encoder consists of Phase A Input, Phase B Input and Index Input, differential conditioning provided
  • Number of Channels: 8
  • Common mode input range: ±7 V maximum
  • Differential Input Range: ±25 V maximum
  • Input Sensitivity: ±200 mV
  • Input Hysteresis: 50 mV Typical
  • Absolute maximum input differential: ±25 V


  • Counter Type: LS7266R1 24 bit Dual Axis Quadrature Counter
  • Clock Frequency: 4.3 MHz maximum
  • Separation: 57 ns min
  • Clock Pulse width: 115 ns min
  • Index Pulse width: 85 ns min
  • Clock Frequency: 30 MHz maximum
  • Clock A: high pulse width 16 ns min
  • Clock B: high pulse width 16 ns min
  • Filter Clock (FCK): Bus Clock (normally 8.33 MHz), Optional Crystal available
  • Digital Filter rate: Same as FCK

Interrupt Controller

  • Controller Type: CPLD
  • Interrupts: Jumper Selectable (2-7, 10-12, 15)
  • Interrupt Sources: All Carry/Borrow outputs from LS7266R1s
    All Index Inputs
  • Addressing: ISA bus address is set by jumpers


  • Operating Temperature: 0°C to 70°C (Optional -40°C to 85°C)
  • Storage Temperature: -50°C to 120°C
  • Humidity: up to 95% RH, non-condensing

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

When ordering RoHS products, please identify this need by using a unique model number suffix, "-RoHS" on all orders. For pricing and lead times, please contact your sales representative.
Part NumberPrice(USD)
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Acquisition Control Communications Engineering / Systems
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