Retronetworking

h1. RS232 vs ITU-T V.24 Signal Names

There are unfortunately a lot of different terms/names used for serial interfaces, depending on which context/spec you are looking at.  

This table provides a mapping of the most common signals between different specs:

|_.Common Name|_.RS232|_.ITU-T V.24|_.Direction|_.Description|

|GND|AB|102|-|Signal/System Ground|

|TXD|BA|103|DTE->DCE|Transmitted data|

|RXD|BB|104|DTE<-DCE|Received data|

|RTS|CA|105|DTE->DCE|Request to Send|

|CTS|CB|106|DTE<-DCE|Clear to Send|

|DSR|CC|107|DTE<-DCE|Data Set Ready|

|DTR|CD|108/2|DTE->DCE|Data Terminal Ready|

|DCD|CF|109|DTE<-DCE|Data Carrier detect|

|-|-|113|DTE->DCE|Transmitter signal element timing (DTE source)|

|-|-|114|DTE<-DCE|Transmitter signal element timing (DCE source)|

|-|-|115|DTE<-DCE|Receiver signal element timing (DCE source)|

|RI|CE|125|DTE<-DCE|Ring Indicator|

|-|-|133|DTE->DCE|Ready for receiving|

* *DTE*: Data Terminal Equipment (Computer/Terminal)

* *DCE*: Data Communications Equipment (Modem/TA)

h2. Full ITU V.24 table

!v24.png!