RS-232C

connectors

What is RS-232C?

Short for recommended standard-232C, a standard interface approved by the Electronic Industries Alliance (EIA) for connecting serial devices. In 1987, the EIA released a new version of the standard and changed the name to EIA-232-D. And in 1991, the EIA teamed up with Telecommunications Industry association (TIA) and issued a new version of the standard called EIA/TIA-232-E. Many people, however, still refer to the standard as RS-232C, or just RS-232.

Almost all modems conform to the EIA-232 standard and most personal computers have an EIA-232 port for connecting a modem or other device. In addition to modems, many display screens, mice, and serial printers are designed to connect to a EIA-232 port. In EIA-232 parlance, the device that connects to the interface is called a Data Communications Equipment (DCE) and the device to which it connects (e.g., the computer) is called a Data Terminal Equipment (DTE).

The EIA-232 standard supports two types of connectors — a 25-pin D-type connector (DB-25) and a 9-pin D-type connector (DB-9). The type of serial communications used by PCs requires only 9 pins so either type of connector will work equally well.

Although EIA-232 is still the most common standard for serial communication, the EIA has recently defined successors to EIA-232 called RS-422 and RS-423. The new standards are backward compatible so that RS-232 devices can connect to an RS-422 port.

Vangie Beal
Vangie Beal
Vangie Beal is a freelance business and technology writer covering Internet technologies and online business since the late '90s.

Related Articles

Software Environment

A software environment is a collection of programs, libraries, and utilities that allow users to perform specific tasks. Software environments are often used by...

ClickUp

ClickUp is a cloud-based work and project management platform that enables teams to manage tasks, collaborate in real-time, gain insights via reporting, and more....

Chunk (Data Chunk)

A chunk, also called a data chunk, by RFC2960 SCTP (Stream Control Transmission Protocol) standards, is the term used to describe a unit of...

Blog Search Engine

A blog search engine is specifically focused on finding content in the blogosphere. Blog search engines only index and provide search results from blogs...

Agile Project Management

Agile project management enables business teams to approach their projects and tasks with...

Private 5G Network

A private 5G network is a private local area network (LAN) that utilizes...

Rich Communication Services (RCS)

Rich communication services (RCS) is a mobile messaging approach in which session initiation...