Rs-232 Serial Port Pin Assignments - 3Com CS/2500 Installation Manual

A-2 A A: P
PPENDIX IN
A
SSIGNMENTS
The table also lists pins assigned for RS-422 functions, when the port is
configured for RS-422 in the firmware. You can use the table as a
reference for cables supplied by 3Com.
CAUTION: A chassis ground connection between the communications
server and customer equipment is strongly recommended. This
connection minimizes the potential for equipment damage caused by
electrostatic discharges. On models CS/2500 and CS/2600, the chassis
ground connection on serial ports can be made only through the
connector headshells. Do not use pin 1 for this connection, since it is not
connected to the chassis.
Table A-1 RS-232 Serial Port Pin Assignments
RS-232-
Pin D Name
1 —
2 BA
3 BB
4 CA
5 CB
6 CC
7 AB
8 CF
9–10 —
11 * DTE
DSR
12 —
13 —
14 —
15 DB
16 —
17 DD
18 —
19 —
20 CD
3Com
Name Direction
— —
TXD In
RXD Out
RTS In
CTS Out
DSR Out
GND —
DCD Out
— —
DCE In
DSR
— —
TXD-B In
TXD-A In
TXC Out
RXD-A Out
RXC Out
— —
RXD-B Out
DTR In
Failsafe
State Function
— Not used
Break Transmit Data
— Receive Data
True Request to Send
— Clear to Send
— Data Set Ready
— Signal Ground
Received Line Signal
Detector (Data Carrier
Detect)
— Not used
— DCE Data Set Ready
— Not used
Break RS-422 Transmit Data
Break RS-422 Transmit Data
— Transmit Clock
— RS-422 Receive Data
— Receive Clock
— Not used
— RS-422 Receive Data
False Data Terminal Ready