Telnet to serial port linux

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При такой схеме передаются данные, но не управляющая информация. Настройка виртуального терминала на хосте client никак не отражается на реальном терминале на хосте server. Это значит, что приложения, которые используют ioctl(2) или termios(3) , не будут работать так, как ожидается.

Способ 2: RFC 2217

Более сложный способ – использовать RFC 2217 для удаленного управления терминалом. Это расширение telnet, которое описывает передачу управляющей информации для последовательного порта.

Сервер

server$ ser2net -d -C '23:telnet:0:/dev/ttyS0'

server$ nc -l -p 23 -c '/usr/sbin/sredird 5 /dev/ttyS0 sredird.lock'

Клиент

client$ kermit -q C-Kermit>set carrier-watch off C-Kermit>telnet SERVER_IP

cyclades-serial-client – клиент для сервера RFC 2217. Он работает с помощью трюка с LD_PRELOAD .

1. Виртуальный терминал /dev/pts/N .
2. Символическая ссылка на него /dev/NAME .
3. Локальный сокет /dev/NAME.control .

Настраиваем конфиг клиента /etc/cyclades-devices (без этого не будет работать трюк с LD_PRELOAD ):

/dev/mytty:prts:SERVER_IP:0:rfc2217:

client$ cyclades-ser-cli -d 3 -m 1 -x /dev/mytty SERVER_IP 0

client$ echo hello > /dev/mytty

Cообщение hello должен получить тот, кто подключен к порту /dev/ttyS0 на хосте server .
Проверяем настройку baud rate :

client$ export LD_PRELOAD=/usr/lib/libcyclades-ser-cli.so client$ stty -F /dev/mytty 38400

server$ stty -F /dev/ttyS0 speed 38400 baud; .

У меня этот клиент работает с сервером sredird , но не работает с ser2net .

• Не все параметры ioctl() реализованы.
• Подход с использованием LD_PRELOAD для ioctl() и tcgetattr() работает не для всех приложений. У меня так и не заработала команда setserial(8) .

And this is still something that should be done in userspace if necessary
by fixing up the tty layer to support pty/tty pair modem lines and
termios change reporting, or some kind of generic vt that can also
expose all the config other net protocols might need.

TTYredirector

TTYredirector реализует сервер и клиент RFC 2217, создавая на клиенте виртуальный терминал. Автоматического перенаправления управляющих команд с локального терминала на удаленный нет, его нужно настраивать вручную с помощью специальной утилиты, так что это решение подвержено тем же проблемам, что способ в socat .

Способ 3: Serial to Ethernet Converter

Serial to Ethernet Converter – устройство, преобразующее RS-232 (и/или другие протоколы) в Ethernet и обратно.

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Telnet into a linux machine using an RJ45-RS232 cable

USB, Ethernet, and serial ports use very very different protocols, also on the physical level (voltages, timings, other electrical characteristics), so you cannot just have «cables» between them. But can Ethernet networks replace serial networks as a drop-in at every layer, up to and including applications? Baud rate will obviously no longer be necessary, but what about other configurable settings such as escape characters? Line wrapping?

Telnet into a linux machine using an RJ45-RS232 cable

my linux machine doesn’t have a RS232 port, only an RJ45. I also have my grandpa’s old pentium machine running windows 95 that has an RS232 port. The only means of interfacing these two computers are via an RJ45-RS232 cable which I acquired a few years ago.

Is there any tool I can use on my linux machine to use my old Pentium as a terminal? Here’s a diagram explaining my goal:

I’d love to be able to work using the 13″ CRT I have connected to the Pentium. Any help is greatly appreciated, thanks.

The cable you have is probably a passive RS232RJ45 adapter which allows using Ethernet cables to carry RS232 signals.

However, it’s still the same RS232 signal in the cable, which means that you can’t connect it to your network interface and expect it to work (and it may be a very bad idea since there’s 12V on a serial cable, more than enough to damage a NIC).

What you need to use is either a serial port on the Linux machine (eventually use another RS232RJ45 to convert the RJ45 connector back into a standard serial connector), or use a device like this that converts RS232 to actual Ethernet (and sends serial data in TCP packets), however that device requires quite a bit of configuration and the first option is way easier.

Frequent ‘serial’ Questions, Tour Start here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site

Using an Rj45 to D9 RS232 Adaptor with a laptop to

Using an Rj45 to D9 RS232 Adaptor with a laptop to control an RS232 deviceHelpful? Please support me on Patreon: https://www.patreon.com/roelvandepaarWith t

How to create an old RS232 Serial Com Port on New PC

Read more information:https://www.wavertec.com/blogs/news/how-to-create- an -old- rs232 -serial-com-port-on-new-pc-deviceBut It Now:https://www.wavertec.com/Wave

How To Connect a Serial Device using USB

Watch this video to learn how to connect a Serial RS232 device to a computer using a USB to serial adapter . The adapter in this video is perfect for connecti

Safely Transition from RS232 “Dumb Terminal” to RJ45 Telnet/SSH

An HPUX 11i network, running on new hardware, for what they call “mission critical” operations at a unique business, terminates for the user at Sherwood 7000STs. While functional (and lightning fast compared to the Web 2.0 systems I grew up with), the terminals connecting via DB-25 (thanks @grawity) RS232 all over the office must be decommissioned. They’ll be replaced with modern Ethernet over RJ45 connections going into a switch with server on a single subnet, and I need to understand how our application will be affected.

Serving an application serially is working fine.

Telnet and SSH are installed.

There are both NIC and COM PCI cards. (LMK if terminology is inaccurate — I will run dmesg tomorrow and update post.)

PROBLEM AS CURRENTLY UNDERSTOOD:

There are many possible configurations of serial terminal.

Telnet and SSH run in terminal emulators when connecting across Ethernet in normal usage.

No firm basis exists for me to expect this application to flawlessly transition.

Previously, server upgrades caused terrible dysfunction between apparently compatible hardware when proprietary wiring meant that our (serial) RJ45 to 25-pin RS232 to 9-pin RS232 conversions had literal crossed wires , as hardware deviated from the spec. Analogies to software are here easy to concieve of, but they should be equally hard to encounter in production!

@Bob — a switch will be in place. What other considerations must I make? See below.

1. Should I expect telnet to “just work” on a new Linux box (like Raspberry Pi ), going into the server? It will be going through a switch, of course. But can Ethernet networks replace serial networks as a drop-in at every layer, up to and including applications?
2. Baud rate will obviously no longer be necessary, but what about other configurable settings such as escape characters?
3. Line wrapping?
4. Paging?
5. Important: What about programs that define terminal display (such as Unibasic)?
6. Important: Will RJ45 run the risk of being somehow “incompatible” with the existing system?

I am confused where processing takes place, and any deeper characterization of the issues above in this context would be appreciated. Mods, please accept this vague question due to the lack of existing discussion on Stack Exchange. I have carefully looked before posting. I am happy to document my research of the existing lit.

You need to be aware that on the HP-UX side, RS-232 interfaces are totally different from network interfaces, which are again different from the telnet API.

If all you use your terminals for is to log in into the HPs, then you can replace that by telnet , or by ssh if you want it to be more secure.

If you have custom software that these terminals connect, then this could be a major problem: You’ll have to adapt the software to deal with the new kind of connection. Which, depending on the software, may be easy, hard or impossible, but it’s the major concern here.

2) Won’t matter, everything is passed through. If you use it to log in, you can still change backspace/del etc. via stty (if that’s what it’s also called on the HPs, been too long since I used one).

3,4,5) Is a function of the way the application and the terminal program interpret control sequences. Transport doesn’t affect this.

You should keep in mind that processing works on layers.

RS-232 and Ethernet («RJ-45») are very different transport technologies, as are protocols ( telnet , ssh ) that work over Ethernet. You should have someone who is familiar with modern network technology, and can install all this for you. If you don’t have one, hire one, or ask another company to do it for you.

Above this transport layer, when the software on both sides just sees a character stream, the differences are minimal.

How to create an old RS232 Serial Com Port on New PC, Read more information:https://www.wavertec.com/blogs/news/how-to-create- an -old- rs232 -serial-com-port-on-new-pc-deviceBut It Now:https://www.wavertec.com/Wave

Any way to access a serial console port using a serial-to-ethernet cable connected to an ethernet-to-USB adapter?

We have a device that has a male serial port on it to access its console. We don’t have a USB-to- female serial cable . I’m trying to see if I can quickly get Access to the console , without having to order a USB-to-female serial cable.

We do have a female serial-to-ethernet cable (looks like this), and an ethernet-to-USB adapter. So I connected the female serial connector on the cable to the device, and the ethernet connector on the cable into the ethernet-to-USB adapter. Then I plugged the adapter into a USB port on a PC running Windows.

On the PC, it detected a «AX88179» which showed up in Device Manager under «Other devices» with a question mark. So I installed the driver for the adapter, and now it shows up as a network adapter ( asix ax88179 usb 3.0 to gigabit ethernet adapter ). No additional COM port showed up under the Ports.

Is there any way for me to access the device’s serial console port ? I have PuTTY installed on the PC, but since there’s no new COM port for this connection, I don’t know how I would access the console.

You’ll have to order an USB-to-serial adapter , that is, an active device, not a cable.

USB, Ethernet, and serial ports use very very different protocols, also on the physical level (voltages, timings, other electrical characteristics), so you cannot just have «cables» between them.

Your «female serial-to-ethernet cable» looks like a D-Sub-to-RJ cable (unless there’s some chip hidden somewhere), for whatever purpose that was used.

But unless there’s a chip hidden somewhere, it won’t do «Ethernet», and if it did, it would be the first device I hear about that can do something like this and looks like a cable.

ethernet-to-USB adapter. [. ] it detected a «AX88179»

So this one has a chip in it, and you can attach it to a network. If you put your D-Sub-to-RJ cable into it, you’ll just have distorted Ethernet signals on whatever pins of the D-Sub plug they are connected to. Which isn’t going to help.

RS232 to MCC communication, Cambiar a Navegación Principal. Inicie sesión cuenta de MathWorks Inicie sesión cuenta de MathWorks; Access your MathWorks Account. Mi Cuenta; Mi …

Interfacing a RS232 printer through USB adaptor

I have a receipt printer that uses a RS232 port. I am thinking of using a USB adaptor to connect it to my PC and then talk/send data to it through my application. My question is, would this still work with an adaptor? Thanks.

If you use Linux, then most probably yes. Most, if not all serial to USB converters are supported, and present a standard serial port to the application, typically called /dev/ttyUSB0 or similar.

On Windows, I cannot confirm — I don’t use Windows. I seem to recall that those adapters, in some cases, but not always, appear as a COMn: port. In this case it should work too. Not always the emulation of the COM port is correct though.

Detecting USB/RS232 adaptor disconnect, Hello, I am currently using a USB port with a USB/RS232 adaptor to produce a RS232 serial port on my Win7 PC. I’m using the SerialPort class for everything and it works well except for one thing. I need a passive way to know when someone unplugs the USB cable while the port is open. I currently · You’ll …

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