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ES-257 Ethernet to Serial Device Server (Ethernet 2 Port RS232)


  • 2 port RS232
  • Max baud rate 1,000,000 (1 MegaBaud)
  • 10/100Base TX Ethernet port
  • User friendly interface, simple to use, powerful in operation
  • Web configuration and RFC2217 compliant interface for non-Windows users
  • IP-30 rated enclosure
  • LED status indication
  • Optional DIN rail mounting kit
  • Serial Port Tunneling (individually configurable) allows serial cable
  • replacement over any distance, no software required
  • Power supply included (power input 5-30V DC)
  • Simple operation for each and every operating system


Ethernet to Serial device server providing access to two RS232 serial ports. Data transfer rates up to 1,000,000 baud, coupled with 1Mbit/s
line drivers deliver uncompromising performance. Our ES range provides simple instant networked serial ports. A web interface allows secure configuration and control of the serial ports over a local network or the internet using any browser. For Windows our in-house designed (32 bit and 64 bit) driver gives you local COM ports, retaining existing software applications and allowing you to connect across your network to remote devices just as if they were attached locally. Serial Port Tunneling (individually configurable) allows serial cable replacement over any distance, no software required. You can access the device via TCP/IP sockets from any networked device like an Android tablet, PC or phone. On Windows OS TCP/IP sockets are handled by the Winsock API, this will differ on other OSs.

Windows Users - Our software drivers gives you local COM ports, allowing you to retain your existing software applications and connect to your devices over the network. COM Port can be assigned from COM1 to COM255 and the Brainboxes Ethernet to serial device remembers your COM Port assignment on reboots.

Web Interface Users (Linux/Apple OS/Android)
- Alternatively access the device via TCP/IP socket from any networked device. Configure options via web interface.


LED Information

Status LED Green Device Ready
  Flashing Yellow Changing Settings
  Flashing between Red & Green Querying IP
  Flashing Green/Red User performing Hard Reset
  Flashing between Green & Red/Yellow IP address diagnostic
  Flashing between Green & Yellow Initialization diagnostic
Serial Port LEDs Green light on Port Open
  Flashing Green Data RX / TX
Network LED Green light on Link Established
  Flashing Green Data RX / TX


Ports 2 port RS232  
Connector DB9 Connector - 9 Pin Male  
Power Input 5 - 30V DC input, reverse polarity protected  
Power Consumption 0.92W Typical  

Port Settings - RS232

Baud Rate From 110 - 1,000,000 (1 MegaBaud)  
Data Bits 5,6,7 or 8  
Parity Odd, Even, None, Mark or Space  
Stop Bits 1 or 2  
Tx/Rx Modes Point to Point  

Port Settings - Ethernet

Data Rate 10/100 Mega bits/second  
Cabling Normal / Crossover auto-sensing (Auto-MDIX)  


Operating Temperature 0 to 55oc  
Storage Temperature -20 to 85oc  
Ambient Relative Humidity 5 to 95% (non-condensing)  
Housing IP-30 rated case  


Network Protocols ICMP, IP, TCP, UDP, DHCP, BOOTP, Telnet, HTTP, RFC2217  
Configuration Options Windows Utility, Web Interface  
OS Compatibility Microsoft Windows 7 32 bit & 64 bit Editions / Windows Server 2008 32 bit & 64 bit Editions / Windows
Vista 32 bit & 64 bit Editions /Windows Server 2003 32 bit & 64 bit Editions / Windows XP 32 bit & 64 bit
Editions / Microsoft Windows 2000 / Fully RFC2217 compliant / Interface for other OS’s & Linux
Connection to Network Ethernet 10BaseT / 100BaseTX  


Industry Approvals AEO C-TPAT Microsoft Certified Gold Partner WEEE RoHS EMC: CE TAA  
Microsoft Approvals Microsoft Certified Gold Partner  
Microsoft Signed Drivers Windows 7 32 bit & 64 bit Editions  
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4 Scar Bank, Warwick, CV34 5DB, United Kingdom.

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