Ask the Expert

What is a null modem and why is it needed?

What is a null modem and why is it needed?

    Requires Free Membership to View

A null modem is a device that basically turns communications into two way communications through a straight wired connection. This is for half-duplex environments where you cannot send and receive on the same cable pairs at the same time (full-duplex). Basically, it swaps the send and receive pairs on one end so that the communication travels on one send pair, gets looped and travels back on the receive pairs.

This was first published in January 2005

There are Comments. Add yours.

TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to: