Wiring; Signal Wiring; Table 5.28:Terminal Or Pc (Dte) Connections - Advantech PCI-COMM Series User Manual

5.2 Wiring

5.2.1 RS-232 Signal Wiring
Since the RS-232 interface is not strictly defined, many devices have their
own connection methods which may ignore some signal lines or define
reserved lines for other functions. It is best to refer to the user's manual
for your device for installation instructions. You may find the following
helpful.
In general, DTE (Data Terminal Equipment) refers to the device that is
leading the communication. Examples include PC's, terminals and some
printers. DCE refers to the device being communicated with or con-
trolled. Examples include modems, DSU's (digital service units), printers
and lab/factory equipment.
In some situations you may be able to get by with just three lines: data on
TXD, a signal ground and a handshaking line. Examples are printer or
plotter connections, troubleshooting and situations where you require
only one-wire communication.
Table 5.28: Terminal or PC (DTE) Connections
DB-25 Male
Pin
2
3
4
5
6
7
20
8
PCI-COMMUNICATION User Manual 92
Signal
TxD
RxD
RTS
CTS
DSR
GND
DTR
DCD
DB-25 Male or Female: Terminal
Pin Signal
3 RxD
2 TxD
5 CTS
4 RTS
20 DTR
7 GND
6 DSR
8 DCD