:
UART Universal Asyncronous Receiver Transiver
CRC Cyclical Redundancy Check
LCD Luquid Cristal Display -
LED Light Emitting Diode -
DTE Data Terminal Equipment - ,
DCE Data Communication Equipment -
: () - DTE DCE (Host-)
-() - DTE DTE (Host-Host)
PC RS-232C:
COM1 - 9 pin , COM2 - 25 pin . -
25 . -
:
Host/DTE(9) >---> /DCE(25)
Host/DTE(25) >---> /DCE(25)
123..5 DB-9 DB-25
67.9 54.321 123...13
9876 14..25
DTE(Host) DCE()
DB9 DB25 | DB-25 Signal
---------+------------------------------------------
1 8 <--- 8 CD Carrier Detect ": "
2 3 <--- 3 RxD Receive Data
3 2 ---> 2 TxD Transmit Data
4 20 ---> 20 DTR D Ready "Host: "
5 7 7 Signal ground
6 6 <--- 6 DSR Data Set Ready ": "
7 4 ---> 4 RTS Request To Send "Host: "
8 5 <--- 5 CTS Clear To Send ": "
9 22 <--- 22 RI Ring Indicator ": "
25 25 :
- .
1 7
2 20
3 2
4 3
5 8
6 22
7 5
8 4
9 6
Host/DTE(25) >---< /DCE(25)
Host/DTE(9) >---< /DCE(25)
1: "" -.
TXD-RXD, DTR-(DSR,CD), CTS-RTS, GND-GND
2: / , .
, 3 .
( ),
4 - 2
, . ,
, Hard-
ware Flow Control (DTR/DSR), Software
(XON/XOFF).
: 2 TxD RxD, - .
, RTS-CTS, DSR-DTR
DCD/DTR.
Host
Signal DB9 DB25 | | DB25 DB9 Signal
-----+----+-----+----------+-----+-------------------
CD 1 8 <-+- - - - 20* 4 DTR
DSR 6 6 <-+ +-- 6 6 DSR
DTR 4 20 - - - -+-> 8 1 CD
GND 5 7 ========== 7 5 GND
RxD 2 3 <========= 2 3 TxD
TxD 3 2 =========> 3 2 RxD
RTS 7 4 ---------> 5 8 CTS
CTS 8 5 <--------- 4 7 RTS
RI 9* 22* 22* 9 RI
: * ;
---
Hardware Flow Control;
- - .
-
CD -<-+ +->- CD
DSR -<-* *->- DSR
DTR ->-+ +-<- DTR
GND ------------ GND
RXD ------<----- TXD
TXD ------>----- RXD
RTS ->-+ +-<- RTS
CTS -<-+ +->- CTS
RJ-11 4pin 2- ;
RJ-8 8pin 2- 4- ;
RJ-45 8pin (Ethernet twisted pair) RS-232;
PLIP ,
pc-pc MSDOS, -
"Laplink". 25 <---> 25
Pin Name Connect pin - pin
--------- -------------------------------
GROUND 25 - 25
D0 ->ERROR 2 - 15
ERROR ->D0 15 - 2
D1 ->SLCT 3 - 13
SLCT ->D1 13 - 3
D2 ->PAPOUT 4 - 12
PAPOUT ->D2 12 - 4
D3 ->ACK 5 - 10
ACK ->D3 10 - 5
D4 ->BUSY 6 - 11
BUSY ->D4 11 - 6
D5 7*
D6 8*
D7 9*
STROBE ? 1*
FEED ? 14*
INIT ? 16*
SLCTIN ? 17*
: , "*" .
Etxra grounds are 18,19,20,21,22,23, and 24.
If the cable you are using has a metallic shield, it should be
connected to the metallic DB-25 shell at one end only.
: , "Laplink"
"" ,
-. .
TTL CMOS /, .
.
RS232:
mark = logical 1 = negative voltage between -3 and -12V
space = logical 0 = positive voltage between +3 and +12V
"" "mark".
:
Start bit (space)
7 or 8 data bits (marks or spaces)
an optional parity bit
1, 1.5 or 2 stop bits (mark)
BREAK (space)
. ( 125ms to
500ms).
/ DTE, /
, BREAK
boot- ,
BREAK ( vt220 BREAK -
F5).
- Sun-
- BREAK, Sun
boot-.
http://www.cisco.com/warp/public/770/fn-tsbreak.html
, BREAK
Order a modified TTY driver from Sun that defeats the interpretation of
the BREAK signal. This driver allows you to re-map the BREAK character
to any custom setting, and does not prohibit the use of L1-A directly from the
master workstation keyboard. The driver part number from Sun is "CONSULT-ZSBRK".
BREAK
A model NUD4273 "non-aborting serial console adapter" from NUData will prevent the
BREAK signal from ever reaching the console port. The devices cost about $89 USD each.
They can be purchaed through Micro Warehouse at http://www.warehouse.com.
"Soldering Iron" - BREAK
If you tie a 4.7K resistor between pins 3 and 25 of the ttya port,
you electrically prevent a BREAK signal either from the key or from disconnecting
or powering down the terminal. This prevents intentional halts except by removing
the resistor, but does allow recabling.
Last-modified: Mon, 16 Sep 2002 12:40:44 GMT