Advantech PCL-849, User Manual

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32 PCL-849 User's Manual
Modem connections
DB-25 Male: PCL-849 Modem (DCE)
Pin Signal Pin Signal
2 TxD 2 RxD
3 RxD 3 TxD
4 RTS 4 CTS
5 CTS 5 RTS
6 DSR 6 DTR
7 GND 7 GND
20 DTR 20 DSR
8 DCD 8 DCD
For DTE to DCE connection, use straight through cable, i.e. you don't
have to reverse lines 2 and 3, lines 4 and 5, and lines 6 and 20.
Because in general the DCE RS-232 interfaces are reversed them-
selves.
Terminal without handshake
DB-25 Male: PCL-849 Terminal, PC (DTE)
Pin Signal Pin Signal
2 TxD 3 RxD
3 RxD 2 TxD
4 RTS —
5 CTS —
7 GND 7 GND
6 DSR —
20 DTR —
8 DCD —
If not using CTS, RTS, DSR ,DTR signals, please loop back for the
PC-ComLIB software to function correctly, because PC-ComLIB will
always check for handshake signals.