[USB-503-RJ45] USB to RS485 Converter (RJ45 type) HuMANDATA LTD.

[USB-503-RJ45] USB to RS485 Converter (RJ45 type)

RoHS10 RS485 RJ45 Isolated SurgeProtection.gif dmx512
NonChemi-Con Flame-retardant-ABS.gif

Compact isolated USB RS-485 Converter
Available LAN cable

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USB-503-RJ45 is a converter that converts from USB to RS485. It is an isolated type that can be used safely even for use in the factory environment.
It is a general specification and can be used for a wide range of applications.
RS485 is equipped with RJ45 connectors used for LANs, and commercially available LAN cable can be used as communication cables, so the work of wiring steps can be reduced.



  • Supports RS485 (Half Duplex)
  • 2000VDC bus isolation
    USB side and RS-485 side are isolated
  • Baud rate up to 250Kbps
    High-speed type USB-010 (MAX 12Mbps) is also available
  • Supports custom baud rate
  • Auto transmit data control
    Built-in USB-serial chip has auto transmit controller and the driver is activated when it transmit the data
  • Built-in fail-safe bias resisters
  • Termination resistance setting switch
  • RJ45 connector
  • No external power supply is required
    USB-503-RJ45 is powered through a USB port (Bus-powered)
  • Reliable industrial grade design
  • ESD and surge protection
    CE-certified USB-003 is also available
  • Housing material: Plastic
  • DIN rail, magnet, and screw mountable (Attachment is required)
  • Includes a USB cable (1.8m)
  • Non-use of 10 Restricted substances of RoHS directive


Item Description Remarks
Model USB-503-RJ45  
Input Power 5VDC
Supplied through a USB port (Bus-powered)
No external power supply required
Current Consumption Less than 80 mA  
I/O Interface RS485 ESD protection ESD_15kV
HOST Interface USB 2.0 compliant
Support Full Speed
USB 1.1 compatible
ESD protection
Baud Rate 300 bps to 250 Kbps Support custom baud rate
Data Bits 7 or 8 bit  
Stop Bits 1 or 2 bit  
Parity Even, Odd, No-parity  
FIFO RX Buffer Size 384 bytes  
FIFO TX Buffer Size 128 bytes  
Isolation Method Bus Isolation  
Isolation Protection 2000VDC Designed value
Processor FT232BL FTDI
USB Driver Virtual COM port driver  
Support OS Windows 10/8.1/8/7  
LED PWR: USB bus power
RX: Receive data
TX: Transmit data
USB Connector Standard Type B Female  
RS485 Connector RJ45 connector Available LAN cable
Operating Ambient Temperature -10 to 60℃ (14 to 140 [°F]) No condensation permitted
Operating Ambient Humidity 10 to 85%RH No condensation permitted
Storage Ambient Temperature -20 to 55℃ (-4 to 131 [°F]) No condensation permitted
Storage Ambient Humidity 10 to 85%RH No condensation permitted
Weight Approx. 70 [g] Only main body
Dimensions 67 x 43.5 x 27 [mm]
(2.638" x 1.713" x 1.063")
Without projections

* Power saving function (suspend, standby, sleep and others) is not supported

RJ45 pinouts

Pin No Name Notes
RJ45  1  B Transmit/Receive data +
2 A Transmit/Receive data -
3 GND Signal ground
4 GND Signal ground
5 GND Signal ground
6 GND Signal ground
7 GND Signal ground
8 GND Signal ground

LAN Twisted Pair Cable Color Codes


  • 1-2 are a twisted pair
  • Make sure to use 8-core cable
  • The color codes might be different in the straight and cross cable

Package Contents

  • USB-503-RJ45
  • USB cable 1.8m
  • Driver & Application CD

Price and Optional Accessories

Description MODEL Image List Price (JPY) Stock Status
USB to RS485 Converter
(RJ45 type)
USB-503-RJ45 USB-503-RJ45
Attachment with clamping screw
PEN-003 PEN-003
Attachment for 35mm DIN rail
Attachment with neodymium magnet
PEN-003-MG PEN-003-MG
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© HuMANDATA LTD. - Altera & Xilinx FPGA Boards manufacturer in Japan - 2016