Table 5.29:Modem Connections; Table 5.30:Terminal Without Handshake - Advantech PCI-COMM Series User Manual

Table 5.29: Modem Connections
DB-25 Male
Pin Signal
2 TxD
3 RxD
4 RTS
5 CTS
6 DSR
7 GND
20 DTR
8 DCD
For DTE to DCE connections, use a straight through cable (i.e., you don't
have to reverse lines 2 and 3, lines 4 and 5, and lines 6 and 20 since, in
general, the DCE RS-232 interfaces are reversed themselves).
Table 5.30: Terminal without Handshake
DB-25 Male
Pin
2 TxD
3 RxD
4 RTS —
5 CTS —
7 GND
6 DSR —
20 DTR —
8 DCD —
Therefore, if you are not using CTS, RTS, DSR ,DTR and DCD signals,
please short pins 4 and 5 together, and please short pins 6, 8,and 20
together.
Modem (DCE)
2
3
4
5
6
7
20
8
Signal
93
Pin
RxD
TxD
CTS
RTS
DTR
GND
DSR
DCD
Terminal, PC (DTE)
Pin
3
2
7
Signal
Signal
RxD
TxD
GND
Chapter 5