howto:electro:rs232_over_ethernet
Obsah
RS232 over Ethernet
(Cisco serial console, RJ45 konzole)
| RJ45 | CAT5 Color | DE9 | RS232 | DE9 Color | |
|---|---|---|---|---|---|
| 1 | orange-white | 8 | CTS | Clear to send | Blue |
| 2 | orange | 6 | DSR | Data set ready | Orange |
| 3 | green-white | 2 | RXD | RX | Black |
| 4 | blue | 5 | GND | Signal GND | Red (not yet! - see below) |
| 5 | blue-white | 5 | GND | Signal GND | Green (not yet! - see below) |
| 6 | green | 3 | TXD | TX | Yellow |
| 7 | brown-white | 4 | DTR | Data terminal ready | Brown |
| 8 | brown | 7 | RTS | Request to send | White (or Grey) |
DB9 - RJ45 redukce
| RJ45 | CAT5 Color | DE9 | RS232 | |
|---|---|---|---|---|
| 1 | orange-white | 7 | RTS | Request to send |
| 2 | orange | 4 | DTR | Data terminal ready |
| 3 | green-white | 3 | TXD | TX |
| 4 | blue | 5 | GND | Signal ground |
| 5 | blue-white | 9 | RI | Ring Indicator |
| 6 | green | 2 | RXD | RX |
| 7 | brown-white | 6 | DSR | Data set ready |
| 8 | brown | 8 | CTS | Clear to send |
(měřeno na zapojeném UTP kabelu)
Rollover kabel
Je potřeba prohodit DB9 piny 2 a 3, na to se používá tzv. rollover kabel, kterej má všechny piny v rj45 zapojený na jedný straně opačně než na druhý…
Null modemy
Null modem je kabel s db9 konektory na obou stranách, s překříženým rx/tx, který nám umožňuje komunikaci mezi dvěmi zařízeními. Zapojení takového kabelu je zde.
Dumb
Loopback handshake
CD Audio Null Modem
Take some old unused analog audio cable from CD drive and swap red and black wires on one side (the two wires closer to each other). Such cable then can be used as null modem when you push it on pins 2,3 and 5 of RS232 DB9 connector. (pin 4 will go to empty position of connector).
Voila! You have smallest and cheapest null modem.
howto/electro/rs232_over_ethernet.txt · Poslední úprava: 2016/10/29 23:05 autor: 127.0.0.1