When you connect any device to a PC (including other PCs or just simple input devices) through any of the available "ports" (i.e. a serial port, parallel port, game port, etc.), you are essentially "networking" the PC with the device. It really does not matter what job the device does, the most important thing is that the two devices are connected to each other with the goal of transferring some sort of data back and forth.

The first PC networks used the serial port and special networking software to link PCs together, however it was soon discovered that the serial port was just too slow to handle large volumes of data. Also, serial data can only be sent over short distances making it difficult to connect computers located far away from each other. In response to the need for faster and longer distance data transfer, special "Network Adapters" were developed that would allow data to be transferred at extremely high speeds over great distances. The network adapters themselves were simply designed as high speed data ports and it was left up to the networking software companies to develop software "protocols" that used the network adapters to transfer data between all the computers (and devices) in a network. The "network protocol wars" soon followed with many different companies developing their own network standards with each trying to corner the market by having their protocol become the standard.

While all of this was going on, a group of researchers working on the development of the Internet came up with a protocol called TCP/IP and released it to the public domain allowing anyone to use it. TCP/IP stands for "Transmission Control Protocol / Internet Protocol". TCP/IP rapidly became the standard that everyone was looking for because nobody owned it or had exclusive control over it and it was also required for connection to the Internet. It is also an extremely well designed protocol that is both cheap and easy to implement. While the popularity of TCP/IP was going up, the cost for network adapters was going down. High quality network adapters are now available for under $20.00.

The TCP/IP protocol is designed such that each PC or device on a network has a unique "IP Address" (Internet Protocol Address) and each IP address can open and communicate over up to 65535 different "ports" for sending and receiving data to or from any other network device. The IP Address identifies the PC or device and a "Port Number" identifies a specific connection between one PC or device and another. A TCP/IP "port" can be thought of as a private communications line where the port number is used to uniquely identify each unique connection between two devices. The concept is very similar to any other type of port on your PC (serial, parallel, etc) except that instead of having a physical connection, the TCP/IP protocol creates a "virtual port" and the network software is responsible for routing the data in and out of each virtual port. Most computer operating systems that support networking are now shipped with complete support for the TCP/IP protocol as well as tools for performing simple TCP/IP I/O operations. For example Windows 95, 98 and NT come with a program called "Telnet" that is similar to a traditional "Terminal" program except that it is designed for TCP/IP communications instead of serial I/O. The HyperTerminal program that is shipped with Windows also supports TCP/IP communications. (Look in your "Accessories" program group under "Communications" for the HyperTerminal program.)

All of this means that it is extremely easy and cheap to create devices that can connect directly to any network that uses the TCP/IP protocol (including the Internet!) and communicate with any other device or computer on the same network.

At the time of this writing, there are not a great number of instruments that are equipped with network adapters but, because of all the benefits of TCP/IP and the low price of network adapter hardware, it is expected that more and more instrument manufacturers will add TCP/IP network interfaces to their devices.

Currently there are however a great number of "network converters" available that will convert RS232 serial data (and other protocols) to TCP/IP network data. These protocol converters make it possible to connect practically any device directly to any network without requiring a PC between the device and the network. For example you could connect an electronic balance that has an RS232 port to a RS232 to TCP/IP converter and then connect the converter directly to a TCP/IP network and make it possible for any computer on the entire network to receive data from the balance. Another option, if a PC is available, is to use TCP-Com software. This allows any of the serial (RS232) ports on your PC to interface directly to a TCP/IP network. It is a software-based RS232 to TCP/IP converter.

The final piece of the puzzle is a software product that can be used to provide the interface between the device that is connected to the network and a standard application program like Excel, Access or any other program. This is exactly the role that TCP-Wedge was designed to fill.

TCP-Wedge
TCP-Com
WinWedge (Software Wedge for Windows)
Links to Hardware Vendors