CH9121 Based 2-CH UART To Ethernet Converter, Serial Port Transparent Transmission Module


  • Operating voltage:3.3V/5V
  • Operating current: 140mA
  • Operating mode: TCP/UDP
  • UART baud rate: 300bps !921.6Kbps
  • UART TTL level: 3.3V/5V compatible
  • Storage temperature: -55°C ~ 125°C
  • Operating temperature: -40°C ~ 85°C
  • Dimensions: 53.00 x 22.00mm
SKU: 39380

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  • Delivery Charges: Tamil Nadu

₹75 for parcels below 1 Kg and ₹100 for parcels weighing between 1 Kg to 2 Kg.

2-3 Days


  • Delivery Charges: Other South India

₹125 for parcels below 1 Kg and ₹175 for parcels weighing between 1 Kg to 2 Kg.

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  • Delivery Charges: North India

₹250 for parcels below 1 Kg and ₹325 for parcels weighing between 1 Kg to 2 Kg.

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Our courier will deliver to the specified address

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Rs. 99

  • Warranty 1 year
  • Free Returns Policy

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  • Embedded Ethernet MAC and PHY layersFeatures

    • Bi-direction transparent data transmission between UART and Ethernet
    • 10/100M, full-duplex/half-duplex auto-negotiation Ethernet interface, 802.3-compliant
    • Auto-MDI/MDIX, detect and switch cable type automatically
    • Supports DHCP auto-obtained IP and DNS domain access
    • Network parameter configuration like chip operating mode, port, IP, via host computer software or UART command
    • Four operating modes: TCP CLIENT, TCP SERVER, UDP CLIENT, UDP SERVER
    • 2-CH UART concurrent operation, standalone transparent transmission for each channel
    • Full-duplex or half-duplex UART communication supports RS485 RX/TX auto switch
    • Supports virtual serial port software (provided)
    • KEEPALIVE mechanism support


2 CH UART TO ETH details 7
5V/3V3power positive, use any pin of 5V/3.3V pins for power supply
RST1external reset input, low active
RESETrestore to factory setting, detected when chip power on, low active
TXD1asynchronous UART 1 data output (enabled by default)
TXD2asynchronous UART 2 data output (disabled by default)
RXD1asynchronous UART 1 data input (enabled by default)
RXD2asynchronous UART 2 data input (disabled by default)
CFG0UART config mode, low level to enter configuration, high level to exit configuration
RUNOperating status indicating pin
DIR1UART 1 RS485 RX/TX switch (connects to external RS485 controller)
DIR2UART 2 RS485 RX/TX switch (connects to external RS485 controller)


CH9121 is a network serial port transparent transmission chip, which can realize the two-way transparent transmission of serial data and network data. It supports 4 working modes of TCP CLIENT/SERVER, UDP CLIENT/SERVER, and the serial port baud rate support range is 300bps~921600bps, which needs to be configured before use. The host computer software NetModuleConfig.exe or serial command configures the network parameters and serial parameters of the chip. After the configuration is completed, CH9121 will saves the configuration parameters to the internal storage space. After the chip is reset, CH9121 will work according to the saved configuration values.

Default configuration

The UART2 is disabled, UART1 works in TCP CLIENT mode by default. The default setting of ETH is as below:

  • Device IP:
  • Subnet Mask:
  • Gateway:
  • Device Port: 2000
  • Target IP:
  • Target port: 1000

The default setting of the UART1 is as below:

  • Baud rate: 9600
  • Timeout: 0
  • data bit: 8
  • Stop bit: 1
  • Parity: None
  • Clearing buffer: Never

2 CH UART TO ETH details 3

2 CH UART TO ETH details 5 1

2 CH UART TO ETH details 5 2

2 CH UART TO ETH details 5 3

2 CH UART TO ETH details 5 4

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