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Serial Ethernet Converter (RS232, RS485, RS422)
Industrial Panel Mount, 4 Ports

  • Model: USC540
  • In Stock


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This 4-port panel mount Serial to Ethernet Converter with RS232, RS485 and RS422 interfaces is identical to part USC520 except that it has 4 serial ports instead of only 2 ports.
Each serial port can be used simultaneously or individually for either RS232, RS485 or RS422.
The serial ports are DB9 connectors which make it easy to connect standard RS232 cables; included are four DB9 / screw terminal headers which makes it easy to connect single wires for RS485 or RS422.
This converter is a strong industrial grade converter with several advanced features. It is ideal for most applications and environments including commercial, industrial applications such as factory automation, warehouse installations and also consumer, office and laboratory applications.

ARM® Cortex™-M4 Processor

This serial to Ethernet converter is designed around the ARM Cortex-M4 processor from Texas Instruments which makes this it a very reliable and high performance converter with several advanced functions. The Cortex-M4 processor incorporates multiple fail-safe and error detection features which ultimately results in less problems and more uptime.

Advanced Features

As mentioned earlier this converter has several advanced features usually not seen in this range of converter, here are some of the features (please refer to the datasheet for all details):

  • Modbus compatible.
    Industrial applications often use the Modbus protocol to communicate with serial devices. This converter is fully compatible with the ModBus TCP and RTU protocols.

  • Both serial ports can be used individually at the same time.
    Both serial ports can be used wither as RS232, RS485 or RS422. The ports can be used as individual COM ports and transfer two separate data streams at the same time. After installing the included Virtual COM Software two separate COM ports will be created in your computer's Device Manager.

  • Multiple Clients Support.
    Each serial port supports up to 8 simultaneous clients in TCP mode, meaning that 8 computers can connect to the converter at the same time. This is a nice feature to have if you have a large network with many clients.

  • Web to Serial Mode.
    You can login to the converter with a web browser over a network and read the serial data processed by the converter.

  • Remote Reboot over TCP.
    If the converter for some reason should require a reboot because of a lock-up, for example due to a power outage or similar, it can be rebooted remotely over TCP by sending a HEX code to the converter. This is a very convenient feature if the converter is located far away.

  • Other Special Functions:
    Just to mention a few of the minor features:
    • Non-standard custom baud rates from 600 to 230.400bps
    • Two TCP sockets can receive data from serial port simultaneously
    • Hardware flow control RTS/CTS
    • Software flow control XON/XOFF
    • User defined MAC address
    • UART and Ethernet Heartbeat packet function
    • Two Ethernet sockets available

    Please see the datasheet and user manual for more details.

Besides the features mentioned above this converter is also fully capable of handling more complex setups such as Serial Tunneling mode, communication without virtual COM software, access over Internet and more.

serial rs232 Ethernet setup

Overall features
  • Very reliable ARM Cortex-M4 processor
  • Industrial strength
  • RS232, RS485 and RSR422 ports
  • Serial ports can be used simultaneously
  • Advanced functions and features
  • Virtual COM port software included
  • Modbus support
  • Configurable via web-browser and software
  • Power supply included

Useful optional accessories
(not included)

Null modem adapter
Null modem adapter

DB9 to RJ45 adapter
DB9 - RJ45 adapter

DB9 gender changer
Gender Changer

Model number USC540
Operating system
Virtual COM software included for:
Windows 11 32/64-bit, Windows 10 32/64-bit, Windows 8 32/64-bit, Windows 7 32/64-bit, Vista, XP
Processor Texas Instruments ARM® Cortex™-M4
Frequency 120MHz
Flash memory 512K
No. of serial ports 4 ports (Combined RS232, RS485 and RS422 in each port)
Port connector type DB9 and screw terminal headers
RS-232 Signals TX, RX, RTS, CTS, GND
RS-485 Signals Data+ , Data-, GND
RS-422 signals TX-, TX+, RX-, RX+
Parity None, Odd, Even, Mark, Space
Data bits 5, 6, 7, 8
Stop bits 1, 2
Flow Control RS232: Hardware (RTS/CTS), Software (XON/XOFF), None
RS485: Automatic Flow Control
Baud rates RS-232: 600 bps - 230.4K bps
RS-485/422: 600 bps - 1024K bps
Non-standard baud rates supported
Buffer size Send and receive 2k bytes respectively
Protection 2KV ESD, lightning protection
Bias resistor Yes, pull-up/down 2.2Kohm
LAN port RJ45, Auto-MDI/MIDX, 2KV isolation
Protocols TCP Server, TCP Client, UDP, UDP Server, HTTPD Client, DHCP, Web to serial, ModBus TCP/RTU
Parameter management Web-browser (over WiFi), by AT commands or by software utility
Modbus Yes (TCP and RTU)
Max number of clients. This is how many computers that can access the converter simultaneously 8 clients for each port in TCP mode.
Power DC 5 ~ 36V adapter or terminal pin
Working current draw 90mA @5V
Watt 1W
Operating Temp. -40°F to 185°F (-40°C to 85°C)
Dimensions 150 x 79 x 30 mm
Weight 804g
Approvals CE, FCC, ROHS
Warranty 1 year Limited Warranty

For alternative serial to Ethernet solutions please see our full selection of serial Ethernet converters.


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