CTS
DCD
DCE
DSR
DSRS
DTE
DTR
FG
NC
RCk
RI
RTS
RxD
SG
SCTS
SDCD
SRTS
SRxD
STxD
TxD
Clear To Send [DCE --> DTE]
Data Carrier Detected (Tone from a modem) [DCE --> DTE]
Data Communications Equipment eg. modem
Data Set Ready [DCE --> DTE]
Data Signal Rate Selector [DCE --> DTE] (Not commonly used)
Data Terminal Equipment eg. computer, printer
Data Terminal Ready [DTE --> DCE]
Frame Ground (screen or chassis)
No Connection
Receiver (external) Clock input
Ring Indicator (ringing tone detected)
Ready To Send [DTE --> DCE]
Received Data [DCE --> DTE]
Signal Ground
Secondary Clear To Send [DCE --> DTE]
Secondary Data Carrier Detected (Tone from a modem) [DCE --> DTE]
Secondary Ready To Send [DTE --> DCE]
Secondary Received Data [DCE --> DTE]
Secondary Transmitted Data [DTE --> DTE]
Transmitted Data [DTE --> DTE]
Description
Function
Shield Ground
Also known as protective ground. This is the chassis ground connection between DTE
and DCE.
Signal Ground
The reference ground between a DTE and a DCE. Has the value 0 Vdc.
Transmitted Data
Data send by the DTE.
Received Data
Data received by the DTE.
Request To Send
Originated by the DTE to initiate transmission by the DCE.
Clear To Send
Send by the DCE as a reply on the RTS after a delay in ms, which gives the DCEs enough
time to energize their circuits and synchronize on basic modulation patterns.
DCE Ready
Known as DSR. Originated by the DCE indicating that it is basically operating (power
on, and in functional mode).
DTE Ready
Known as DTR. Originated by the DTE to instruct the DCE to setup a connection.
Actually it means that the DTE is up and running and ready to communicate.
Ring Indicator
A signal from the DCE to the DTE that there is an incomming call (telephone is ringing).
Only used on switched circuit connections.
Received Line Signal Detector
Known as DCD. A signal send from DCE to its DTE to indicate that it has received a
basic carrier signal from a (remote) DCE.
Data Signal Rate Select
(DTE/DCE Source>
A control signal that can be used to change the transmission speed.
Transmit Signal Element Timing
(DTE Source)
Timing signals used by the DTE for transmission, where the clock is originated by the
DTE and the DCE is the slave.
Transmitter Signal Element Timing Timing signals used by the DTE for transmission.
(DCE Source)
Receiver Signal Element Timing
(DCE Source)
Timing signals used by the DTE when receiving data.
Local Loopback / Quality Detector
Remote Loopback
Test Mode
Reserved for Testing
Originated by the DCE that changes state when the analog signal received from the
(remote) DCE becomes marginal.