4-port, RS-232/422/485 serial communications board

United Electronic Industries is a leader in the PC/Ethernet data acquisition and control, Data Logger/Recorder and Programmable Automation Controller (PAC) and Modbus TCP markets.

UEI guarantees the availability of all RACKtangle®, Cube, and FLATRACK™ series products (including DNA, DNR, UEIPAC, UEISIM, UEILogger and UEIModbus chassis and compatible I/O boards, manufactured by UEI) for a minimum of 10 years.3 year warranty standard on UEI products

4-port, RS-232/422/485 serial communications board
Availability: Typically in stock for 1-2 week delivery.


  • 4 independent ports
  • Each port is software-configurable as RS-232 or RS-485
  • Compatible with Half- and full-duplex support
  • Max speed of 256Kbit/s for RS-232 and 2 Mbit/s for RS-485
  • Completely independent bit rate settings for every port
  • 350V isolation between ports, ports and circuitry
  • Compatible with RS-422 networks when used in RS-485 mode
  • Half- and Full-duplex support for RS-485
  • Includes UEI-RSS Remote Serial Server application, Windows and Linux versions

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Product Description

The DNx-SL-501 is a 4-port serial communications board (layer) for PowerDNA distributed automation and control system. This board (layer) offers isolated serial interfaces software-configurable as RS-232 or RS-485. DNx-SL-501 supports up to 2 Mbit/s transfer speed in RS-485 mode or up to 256Kbit/s in RS-232 mode. DNx-SL-501 uses 16550 UART controller on each port (FIFO mode only) and supports half- and full-duplex mode for RS-485.

The DNx-SL-501 includes the UEI-RSS Remote Serial Server application, Windows and Linux versions. This server allows a Windows or Linux host PC to configure the DNx-SL-501 ports as standard serial ports within the host OS (e.g. as COM1: to COM255: ports in Window or standard POSIX functions in Linux). The UEI-RSS supports up to 255 unique serial ports per Ethernet port on the host.