APPENDIX A: Interface Pinouts
51
Table A-2 (continued). Sub-channel connectors.
CCITT V.24 EIA RS-232C
RJ-45
Signal
Name
Description
Circuit
Line
Pin
106
CB
8
Clear to Send
A positive level from the stat mux
indicates that the terminal is allowed
to send data. This pin is used for
hardware flow control. Computers
or terminals which do not support
this pin (they send data even if CTS
is negative) must have software
flow-control ability.
109
CF
4
Data Carrier
Positive level from stat mux when
Detect
the local and remote stat mux are
synchronized
108
CD
6
Data Terminal
Used for end-to-end flow control
Ready
Sub-channel connection cables depend on application: a port (straight-through) cable is generally used to
connect the stat mux to a DTE, and a modem (crossover) cable is used to connect the stat mux to a tail-end
modem (see Figure A-1).
Figure A-1. Typical sub-channel cable wiring.
