Serial to Ethernet converters - extended tutorial for technicians

There are certain operational scenarios that may require you to convert back and forth between Ethernet IP/TCP packets and serial transmissions from devices using the RS232/RS422/RS485 protocols. To accomplish this feat you will often use a piece of hardware called a serial to Ethernet converter. This small device is also known as a serial device server and models are available in various sizes.

In this article, we will try to figure out how remote RS232 and other serial ports work and talk about the methods to use RS232 to Ethernet technology, or in fact, convert any serial port over the network.

Contents

1. Serial to Ethernet Connector
   1.1. Serial to Ethernet Converter software tutorial
2. Hardware solutions to convert RS232 to Ethernet
   2.1. Types of Serial to Ethernet devices
   2.2. How to set up
3. Best Serial to Ethernet Hardware list
   3.1. NetBurner RS232 to Ethernet adapter
   3.2. Perle serial over IP solution
   3.4. SerialLynx COM to Ethernet adapter
   3.4. Lantronix RS232/485 to IP converter
4. Serial to Ethernet converter - who is it for?
   Conclusions

When it's not possible to physically connect a COM port peripheral to a hardware RS232 to Ethernet converter, you can share the device using a serial to Ethernet software.

Serial to Ethernet Converter software

Serial to Ethernet Connector, is not limited by the distance. It lets you connect to any number of remote COM ports from your computer regardless of their physical location. To share a serial device to Ethernet, you only need to install the program on the server and client sides, and configure connections.

With its help you get access to serial ports supporting various protocols, no matter where they are actually located. Now you can forget your worries about the length of the cable connecting your serial device and computer. Serial to Ethernet Converter allows you to display and access serial ports converted to Ethernet, as if they were on your local machine.

That’s it, now you have full access to the functionality of the remote devices.

Hardware solutions to convert RS232 to Ethernet

Hardware converters with RS232/485 to Ethernet technology are actually compact servers that connect autonomous devices with serial interface to Ethernet.

If you are going to work with serial ports over network protocols, there’s a good chance that you’ll need a special tool called RS485 to Ethernet converter (known alternatively as serial to Ethernet adapter). This solution is designed to convert data received from a RS232/485 port into TCP/IP data. The tool provides users with the ability to fully interact with remote COM ports without having them physically present on their local machines. Any remote serial port can be shared and accessed over the network with the help of RS232 over Ethernet solution.

Types of serial to Ethernet Connectors:

The device can in fact be called a serial to Ethernet converter, adapter, console, or device server and come in various models, depending on the number of fitted serial ports. Here are some examples of serial to Ethernet hardware:

1-port model, multiport model, wireless model

NetPort by L-com is one of the most popular implementations of a single port serial server. This RS232-to-Ethernet cable connector with a built-in web server lets any peripheral inserted into it be shared over the TCP/IP protocol stack. The solution is designed to connect an RS-232 serial port to an Ethernet IP network and costs $143.25.

Serial to Ethernet connectors usually fit from 1 to 48 COM ports. However, the number of ports can vary depending on the manufacturer. Serial servers that have from 1 to 8 COM ports are known as multi-port models.

8-port Serial Device Server ESE-400D by B&B Electronics is a good example of such multi-port device. The server supports RS-232, RS-422 and 485 standard on all serial ports. Featured with a built-in web server the device can be easily configured through a web browser. The solution supports serial tunneling, IP multicast, surge suppression, and +5V Out option. The server can be purchased for $875.00.

In case you need to connect your serial or Ethernet devices to a wireless LAN, a good idea will be to try a wireless device server like NPort W2000A Series by MOXA. This 2-port RS-232/422/485 tool is able to link a serial device to an IEEE 802.11a/b/g network. The solution features a built-in WLAN site survey tool and supports off-line port buffering and serial data log. What’s more, the server provides secure data access with WEP, WPA, WPA2. The price for this hardware device starts from $305.

The problem here is that just like any hardware solution, it has certain restrictions:

• The number of converted devices is strictly limited by the converter’s specification. Manufacturers typically make converters with 1, 2, 4, 8, 16, or 32 ports.
• Also note that not all converters provide simultaneous support to RS422/232/485 protocols. More often you have to choose one type of serial port protocol.
• To display a serial device on your computer, you will need additional software to emulate virtual serial port.

How to set up RS232 to Ethernet adapter:

1. First, assign a static IP address to your computer.
2. Prior to using a Serial to Ethernet hardware solution, you will be required to install a software driver on your computer. This driver software, which is often referred to as virtual COM software, is commonly included with your converter purchase. The software creates a virtual serial port that is visible in Device Manager when the converter is connected to the machine.
3. Connect RS232 to Ethernet converter to your computer using either a standard Ethernet cable or crossover or straight-through cable. Connect it to the power supply.
   To check the connection, enter the converter’s IP address in your browser and press Enter. This should take you to Admin’s page, and if you do not see it, redo the setup procedure for the converter.
4. Launch the software and click ‘Search’. Once your RS232 to Ethernet converter is found, click ‘Create COM port’ button to create a virtual port.

Now go to Device Manager on your computer – the newly created port should be displayed there. If it is nowhere to be seen, go back to the setup procedure.

Best Serial to Etherent Converters - tested hardware

Choosing a decent network converter from a wide variety of brands and configurations available today can be rather challenging, so we prepared a list of five most popular serial to Ethernet converters which stand out for their efficiency and ease of use.