• es 257 ethernet 2 port rs232
  • ES 257 RS 232 Pinout
  • ES 257 back
  • ES 257 front
  • ES 257 side
es 257 ethernet 2 port rs232
  • 2 Port RS-232
  • Ethernet to Serial Device Server
  • Data rate from 110 to 1,000,000 baud
  • Install Virtual Com ports or use the Software APIs for Visual Basic, C# and more
  • Serial Port Tunnelling allows serial cable replacement over any distance, no software required
  • Power supply included (power input 5-30V DC)
  • ES-257-datasheet (0.80 MB)
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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 Tunnelling (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.

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Tech Spec

Serial Port
ConnectorDB9 Connector - 9 Pin Male
Tx FIFO Size256
Rx FIFO Size32
Operating DistanceEIA - RS232 Standard
CableNo Cable; Integrated Connector
Serial Port Settings
Max Baud Rate1,000,000 (1 MegaBaud)
Data Bits5,6,7 or 8
ParityOdd, Even, None, Mark or Space
Stop Bits1 or 2
Tx/Rx ModesPoint to Point
Power Input5 - 30V DC input, reverse polarity protected
Power Over EthernetNo - this product does not have PoE capability
Power Supply 1 DescriptionGlobal Power Supply - PW-800
Power Supply 2 Description
Mounting Accessories 1 DescriptionDIN-Rail Mounting Kit - MK-048
Mounting Accessories 2 Description
PCB Layers4
Operating Temperature Range0 °C to +60 °C / 32 °F to +140 °F
Device Dims with ears96.3x101x25
Device Dims without ears91.6x77x25
Power Consumption0.92W Typical
Product Weight0.126 kg, 4.44 ounces
Product Dimensions106x105x28 mm, 4.2x4.1x1.1 inches
Packaged Weight0.379 kg, 13.37 ounces
Packaged Dimensions200x135x80 mm, 7.9x5.3x3.1 inches
GTIN (barcode)837324001778
Operating System Compatibility
Operating Systems
  • Microsoft Windows 10
  • Microsoft Windows 7 32 bit & 64 bit Editions
  • Windows Server 2008 32 bit & 64 bit Editions
  • Windows Vista 32 bit & 64 bit Editions
  • Windows XP 32 bit & 64 bit Editions
  • Microsoft Windows 2000
EthernetEthernet Interface takes advantage of a companies pre-existing infrastructure, allowing you to connect to your Brainboxes device over the local network, or from across the world.


Microsoft Signed Drivers

Microsoft Hardware



Typical Product Applications

  • To remotely run service tills at a restaurant
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  • Undergoing Virtualisation project and need Fax Modems to send receive orders in between two sites of their Retail stores
  • Connecting enterprise telemetry SCADA system to banks of modems
  • Connect to DO Meters WTW - Measures Dissolved Oxygen