Null Modem Cable
Get the null modem cable you need for your network.
One of the most prominent communication methods for connecting 2 DTEs such as terminal, computer, or printer is a RS-232 serial cable or null modem cable. This cable allows the transmit line and the receive line as well as some handshake lines to crosslink. On the other hand, a standard does not cover null modem connection; as such some wiring layouts are used.
A null modem cable was originally developed in order to be used for teletype machines that are able to communicate with each other through phone lines. In older days, each teletype is connected physically to the modem through RS-232 connections. The modem would communicate with each other to build a remote connection between all teletypes. More so, if a user prefers to connect a couple of teletypes without modems, they would need to crosslink the connections. Thus, null modem cable has also been referred to as an adaptor, cable, or a connection method.
As mentioned earlier, a null modem has been established to connect 2 teletypes without using modems. As years pass, the RS-232 standard has been applied to other types of equipment as designers were prompted to decide over having DCE-like or DTE-like interfaces. The null modem has been necessary for establishing communication between 2 DTEs or DCEs as the application requires.
Today, null modems are being used for transferring files between computers. Based on the Microsoft Windows operating system, a null modem can be used with a direct cable connection. On the other hand, some versions of MS-DOS were shipped together with the InterLnk program. Both software pieces allow hard disk mapping on a computer, making it a network drive on another computer. Consequently, this type of application does not need any Ethernet hardware such as a modem or network interface card. As the Ethernet was able to gain its popularity for use in transferring files or faster information exchanges, the use of null modems has become uncommon.
Today, null modems are mostly used by kernel hackers because it enables a user or a hacker to debug a kernel remotely under minimum device drivers and code. The code is usually a serial driver that includes an interrupt service routine as well as 2 FIFO buffers. Null modems are also being used in the administration of headless devices. These null modems provide a serial administration console such as rack-mount server units, different embedded systems, and managed switches among others.
One of the most popular null modem is the Tripp Lite P454-006 Null Modem Gold Cable DB9M/F. This null modem allows 2 serial devices to connect with each other. It is a 6-feet cable that comprises a DB9 female connector and a DB9 male connector on each end. The Tripp Lite P454-006 Null Modem Gold Cable DB9M/F is molded with high quality foil shielding. This high quality foil shielding provides optimized and superlative EMI and RFI protection. The Tripp Lite P454-006 Null Modem Gold Cable DB9M/F has gold-plated contacts and connectors, which offer superior and efficient conductivity.