Multitech MT5600BA - Manual (Page 59)

Appendix F - Pin Descriptions
RDL 21 RDL Remote Digital Loop Input to modem to enable RDL test.
RI 22 Ring Indicator RI output high indicates the presence of
a ring signal on the telephone line.
23 NC
XCLK 24 XCLK External Clock Input to modem used in special
synchronous applications.
TM 25 TM Test Mode Output from modem to indicate modem is in
one of the test modes.
R R R R RS S S S S-----232 Cab 232 Cab 232 Cab 232 Cab 232 Cable P le P le P le P le Pinouts inouts inouts inouts inouts
20 DTR
22 RI
8 CD
7 GND
6 DSR
5 CTS
4 RTS
3 RD
2 TD
DTE DB-25
connector
DCE DB-25
connector
DTR 20
RI 22
CD 8
GND 7
DSR 6
CTS 5
RTS 4
RD 3
TD 2
Fig. F-1. 25-pin to 25-pin RS-232 cable.
20 DTR
22 RI
8 CD
7 GND
6 DSR
5 CTS
4 RTS
3 RD
2 TD
DCE DB-25
connector
DTE DB-9
connector
DTR 4
RI 9
CD 1
GND 5
DSR 6
CTS 8
RTS 7
RD 2
TD 3
Fig. F-2. 9-pin to 25-pin RS-232 cable.
Label Pin I/O type Signal name/description