Editing RS-232 (section)

==Limitations of the standard==
Because RS-232 is used beyond the original purpose of interconnecting a terminal with a modem, successor standards have been developed to address the limitations. Issues with the RS-232 standard include:<ref>{{cite book |author-last1=Horowitz |author-first1=Paul |author-link1=Paul Horowitz |title=The Art of Electronics |year=1989 |publisher=[[Cambridge University Press]] |location=Cambridge, England |edition=2nd |author-first2=Winfield |author-last2=Hill |author-link2=Winfield Hill |isbn=0-521-37095-7 |pages=[https://archive.org/details/artofelectronics00horo/page/723 723–726] |title-link=The Art of Electronics }}</ref>
* The large voltage swings and requirement for positive and negative supplies increases power consumption of the interface and complicates power supply design. The voltage swing requirement also limits the upper speed of a compatible interface.
* Single-ended signaling referred to a common signal ground limits the noise immunity and transmission distance.
* Multi-drop connection among more than two devices is not defined. While multi-drop "work-arounds" have been devised, they have limitations in speed and compatibility.
* The standard does not address the possibility of connecting a DTE directly to a DTE, or a DCE to a DCE. [[Null modem]] cables can be used to achieve these connections, but these are not defined by the standard, and some such cables use different connections than others.
* The definitions of the two ends of the link are asymmetric. This makes the assignment of the role of a newly developed device problematic; the designer must decide on either a DTE-like or DCE-like interface and which connector pin assignments to use.
* The [[handshake (computing)|handshaking]] and control lines of the interface are intended for the setup and teardown of a [[modem#Dial-up|dial-up]] communication circuit; in particular, the use of handshake lines for [[flow control (data)|flow control]] is not reliably implemented in many devices.
* No method is specified for sending power to a device. While a small amount of current can be extracted from the DTR and RTS lines, this is only suitable for low-power devices such as [[computer mouse|mice]].
* The [[D-subminiature|DB-25 connector]] recommended in the standard is large compared to current practice.