User`s guide

Pin Assignments
134
DB-9 Port Pin
Assignments
Connection from
Switch’s Serial
Port to 9-Pin
COM Port on PC
EIA
Circuit
CCITT
Signal
Description
Switch’s
DB9 DTE
Pin #
PC DB9
DTE
Pin #
Modem
DB25
DCE Pin
#
Signal
Direction
DTE-DCE
CF 109 DCD (Data Carrier Detected) 1 1 8
BB 104 RxD (Received Data) 2 2 3
BA 103 TxD (Transmitted Data) 3 3 2
CD 108.2 DTR (Data Terminal Ready) 4 4 20
AB 102 SG (Signal Ground) 5 5 7
CC 107 DSR (Data Set Ready) 6 6 6
CA 105 RTS (Request-to-Send) 7 7 4
CB 106 CTS (Clear-to-Send) 8 8 5
CE 125 RI (Ring Indicator) 9 9 22
Switch’s 9-Pin Serial
Port
CCITT Signal PC’s 9-Pin COM Port
1 DCD DCD 1
2 RXD TXD 3
3 TXD RXD 2
4 DTR DSR 6
5 SGND SGND 5
6 DSR DTR 4
7 RTS CTS 8
8 CTS RTS 7
9 RI RI 9