User`s guide

Installation
2-4 Modem 3600
Table 2-1. Pin Signal Description s
Pin
EIA-
232D
CCITT
V.24 Signal Description
1 101 Shield No connection
2 BA 103 Trans-
mitted
Data
Serial digital data (to be
modulated) from a data terminal or
other digital data source:
Synchronous data must be
accompanied by the modem
transmit clock (pin 15) or by an
external data rate clock (pin 24).
Data transitions should occur on
positive-going clock transitions;
asynchronous data does not
require a transmit clock.
3 BB 104 Receive
d Data
Serial digital data output to the
DTE interface: Sync data is
accompanied by an internal data
rate (receive) clock (pin 17) that
has positive-going transitions on
the data transition. Async data
does not require a receive clock.
4 CA 105 Request
to Send
A positive level to the modem
when data transmission is desired
5 CB 106 Clear to
Send
A positive level from the modem
in response to Request to Send and
when the modem is ready to
transmit. *
6 CC 107 Data Set
Ready
A positive level from the modem
when power is on and ready to
operate: In dial-up operation, the
modem must be off hook to give a
high DSR signal.*
*
* Modem options may force these signals on or cause them to be ignored.
*
** Refer to Appendix C, Hardware Options.
*
† This function can be disabled or its logic sense reversed by hardware straps.