Table Of Contents

USB-485/4 Pinout

Version:
    Last Modified: March 20, 2017

    Table 1. Signal Descriptions
    Signal Description
    GND Ground.
    CTS+, CTS- Clear To Send Positive Reference, Clear To Send Negative Reference. Also known as Hand Shake In Positive (HSI+) and Hand Shake In Negative (HSI-).
    RTS+, RTS- Request To Send Positive Reference, Request To Send Negative Reference. Also known as Hand Shake Out Positive (HSO+) and Hand Shake Out Negative (HSO-).
    RXD+, RXD- Received Data Positive Reference, Received Data Negative Reference.
    TXD+, TXD- Transmitted Data Positive Reference, Transmitted Data Negative Reference.
    Table 2. LED State/Device Status
    LED LED Color LED State Device Status
    READY Red Dimly lit Powered, but not connected to USB (self-powered USB only).
    Lit Powered and connected to USB, but not fully configured.
    Yellow Lit Device is ready (normal operation).
    Red or Red/Yellow Blinking Device error. Contact NI.
    PORT x Red Blinking Port error (framing error, FIFO overrun, or parity error).
    Green Lit Port is open.
    Blinking Port is receiving.
    Yellow Blinking Port is transmitting.
    Green/Yellow Blinking Port is transmitting and receiving.

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