Cyclades AlterPath ACS, Справочник по командам

Страница: 395 / 420

Connectors
| 379
C.2 Connectors
The connector traditionally used with RS-232 is the 25-pin D-shaped connector (DB-
25). Most analog modems and most older computers and serial equipment use this
connector. The RS-232 interface on DB-25 connector always uses the same standard pin
assignment.
The 9-pin D-shaped connector (DB-9) saves some space and is also used for RS-232.
Most new PC COM ports and serial equipment (specially when compact size is
important) uses this connector. RS-232 interfaces on DB-9 connectors always use the
same standard pin assignment.
The telephone-type modular RJ-45 plug and jack are very compact, inexpensive and
compatible with the phone and Ethernet wiring systems present in most buildings and
data centers. Most networking equipment and new servers use RJ-45 connectors for
serial communication. Unfortunately there is no standard RS-232 pin assignment for RJ-
45 connectors. Every equipment vendor has its own pin assignment.
Most connectors have two versions. The ones with pins are said to be “male” and the
ones with holes are said to be “female.”
RS-232
Signal
Name/Function
(Input/Output)
DB-25 pins
(Standard)
DB-9 pins
(Standard)
RJ-45 pins
(Cyclades)
Chassis Safety Ground 1 Shell Shell
TxD Transmit Data (O) 2 3 3
RxD Receive Data (I) 3 2 6
DTR Data Terminal Ready (O) 20 4 2
DSR Data Set Ready (I) 6 6 8
DCD Data Carrier Detect (I) 8 1 7
RTS Request To Send (O) 4 7 1
CTS Clear To Send (I) 5 8 5
GnD Signal Ground 7 5 4
Table C.5: Cables and their pin specifications