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DigiBoard Intelligent Serial Communications Boards
Connecting Peripherals
Connecting to a Modem
DB-9 Equipped Boards
To connect a DB-9 equipped board to a modem, use standard PC modem cables,
available from most electronics stores and computer dealers. The wiring dia-
gram for a 9-pin to 25-pin modem cable is shown in Figure 17.
Figure 17
DB-9 to DB-25 Modem Cable
DB-9 Female
DB-25 Male
8
3
2
20
7
6
4
5
22
1
Pin
Pin
DCD
RxD
TxD
DTR
SG
DSR
RTS
CTS
RI
GND
DCD
RxD
TxD
DTR
SG
DSR
RTS
CTS
RI
GND
Signal
1
2
3
4
5
6
7
8
9
Shell
Signal
( Cable Shield)
Shielded cable must be used to remain in compliance with
Part 15 of FCC rules.