CommunityForumWikiBlogLearn
Modules
IO Expansion Shields & HATs

RS485 Connector Expansion Shield for LattePanda Alpha&Delta

SKU: DFR0779

This article introduces the RS485 Connector Expansion Shield designed for LattePanda Alpha, Delta, and 3 Delta models. It offers two parallel RS485 ports with high reliability using FTDI USB to serial port chip and industrial-grade isolated transceiver module. Key features include signal isolation, power isolation, lightning and surge protection, transient impulse voltage resistance, and bus protection, ensuring reliable data transmission and protecting your LattePanda mainboard. The stackable connection allows easy installation without obstructing heat dissipation, making it ideal for industrial scenarios.

Front of RS485 connector expansion shield for LattePanda, featuring COM port and female RS485 connector.-DFRobot product sku:DFR0779 image.

Downloadable Resources

  • Docs
  • Tech Specs
    • 1. Getting Started

    This paper serves as a detailed guide for first-time installation and usage of FTDI chip drivers on Windows, highlighting necessary precautions and steps for a successful setup.
    2. Example Code for Host Computer-RS485 Relay Control

    This article offers a comprehensive guide for controlling RS485 relays using host computer software, detailing hardware requirements, software preparations, wiring instructions, and operational steps to efficiently manage relay modules with LattePanda Alpha & Delta systems.
    3. Example Code for Serial Port Assistant-RS485 Relay Control

    This article guides users through controlling an RS485 relay using Serial Port Assistant, covering hardware setup with LattePanda boards, software preparation, wiring diagrams, and sending correct commands for relay control.
    4. Example Code for Modbus Assistant-RS485 Relay Control

    The article offers step-by-step guidance and example code for utilizing Modbus Assistant to control RS485 relays, detailing hardware and software preparations, wiring connections, and Modbus protocol instructions for effective relay module management.
    5. Example Code for Python-RS485 Relay Control

    The article demonstrates the use of Python's ModBus library to control a DFR0290 8-channel relay, providing step-by-step guidance and example code for effective relay management through the RS485 protocol.
    Reference

    The article provides an overview of RS485 and ModBus communication protocols, detailing RS485's resistance to noise interference and long-distance transmission capabilities, and explaining ModBus's master/slave architecture and its variants like RTU, ASCII, and TCP/IP.

    Specification

    Parameter Value
    Module operating power +5V
    Compliance EIA/TIA-232-F standard
    Communication baud rate up to 1M bps
    Maximum power output 12V
    Isolation voltage 3000 VDC
    Bus load capacity 1/8 unit load, up to 256 nodes
    Protection features Bus fail-safe and bus drive short circuit protection
    Operating temperature range -40℃ to +105℃

    Pinout

    Board OverView

    LattePanda Alpha&Delta pin function description (recommended to refer to LattePanda Alpha official wiki & LattePanda Delta official wiki)

    FAQ

    • Hello, in the product wiki, the following is mentioned: "RS485 requires 2 terminal resistors, and its resistance value must be equal to the characteristic impedance of the transmission cable (usually 120Ω). In short-distance transmission, there is no need for terminal resistors." Please could you quantify the cable length which is considered as short-distance?

      Due to the quality of the wires used by users, we cannot give a very precise number.
      But generally in transmission below 300m, you do not need to use terminal resistors

    Explore More Related Questions >

    Was this article helpful?

    TOP