Table Of Contents

Digital I/O Specifications

Version:
    Last Modified: May 14, 2018

    Number of DIO channels

    40

    Direction control

    Individually programmable as input or output

    Logic level

    5 V compatible LVTTL input; 3.3 V LVTTL output

    Pull-up/down

    40.2 kΩ pull-up to 3.3 V[1]

    Protection

    ±30 V

    Input logic levels
    Input low voltage, VIL

    Minimum

    0 V

    Maximum

    0.8 V

    Input high voltage, VIH

    Minimum

    2.0 V

    Maximum

    5.25 V

    Output logic levels
    Output low voltage, VOL sinking 4 mA

    Minimum

    0 V

    Maximum

    0.4 V

    Output high voltage, VOH sourcing 4 mA

    Minimum

    2.4 V

    Maximum

    3.465 V

    Minimum output pulse width

    20 ns

    Maximum frequencies for secondary digital functions

    SPI

    4 MHz

    PWM

    100 kHz

    Quadrature encoder input

    100 kHz

    I2C

    400 kHz[2]

    UART lines

    Maximum baud rate

    230,400 bps

    Data bits

    5, 6, 7, 8

    Stop bits

    1, 2

    Parity

    Odd, Even, Mark, Space

    Flow control

    XON/XOFF

    • 1 The NI ELVIS III enables a 40.2 kΩ pull-up to 3.3 V on the DIO lines by default. If the NI ELVIS III detects an application board designed for the NI ELVIS II/II+, it enables a 40.2 kΩ pull-down to Ground on the DIO lines instead.
    • 2 I2C requires an additional pull-up resistor on I2C_SCL and I2C_SDA for correct operation. Some I2C devices already include suitable pull-up resistors, others require that the resistors be added explicitly on the application board. Typical resistor values range from 1 kΩ to 10 kΩ.

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