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APPENDIX A: Interface Pinouts
A.2 Sub-Channel Interface
The MiniStat-Four’s sub-channel interfaces are configured as asynchronous RS-232
interfaces, pinned as DCE, with female DB25 connectors. The pinout (“pin
allocation”) of these interfaces is listed in Table A-2.
What type of sub-channel connection cables you use depends on what type of
devices you’re attaching: use a port (“straight-through”) cable to connect the
MiniStat-Four to a DTE; use a modem (“crossover”) cable to connect the MiniStat-
Four to a tail-end modem. See Figure A-1.
Table A-2. Sub-channel connectors.
CCITT V.24 TIA
PIN
SIGNAL
DESCRIPTION
CIRCUIT
RS-232C
NAME
NUMBER
LINE
101
AA
1
Protective Chassis
ground
Ground
(may be isolated from
signal ground or connected
to it.
102
AB
7
Signal
Common ground for signal
Ground
leads and DC power supply.
103
BA
2
Transmit
Serial digital transmit data
Data
from the attached device.
104
BB
3
Receive
Receive data provided by
Data
MiniStat-Four receiver.
