I’m trying to set up a communication link for an old project, and I’ve hit a snag. It looks like I need to emulate a null modem connection, but I’m not sure how to do that with my current hardware and software. Can anyone guide me on how to set this up? Any recommended software or steps would be really helpful.
If you need to emulate a null modem connection, it’s definitely a bit of a throwback to older tech, but totally doable! Here’s a step-by-step method to get you up and running.
Hardware Setup
- USB-to-Serial Adapters: If your current hardware lacks serial ports, grab a couple of USB-to-Serial adapters. These can be found pretty cheaply online.
- Null Modem Cable: Alternatively, you could buy a physical null modem cable if your machine supports traditional 9-pin serial ports.
Software Setup
-
Virtual Serial Port Driver: This software can emulate a null modem connection virtually. You can set up virtual COM ports on your computer which communicate with each other, bypassing the need for physical serial port hardware.
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Install the Software: Once you download and install the Virtual Serial Port Driver, launch the program.
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Create Virtual Ports: Use the software’s interface to create a pair of virtual COM ports (e.g., COM1 ↔ COM2). These ports will behave as though they’re linked with a null modem cable.
Detailed Steps:
- Open the Virtual Serial Port Driver and click on “Add Pair.”
- Configure Settings: You might have options for port names, emulation parameters, etc. Configure these as needed.
- Confirm and Create: Complete the setup by confirming and creating the virtual ports. The software does most of the heavy lifting.
Testing the Setup:
- Serial Terminal Software: Use software like PuTTY or Tera Term to open and test the virtual serial ports.
- Communication Test: Open two instances of your terminal software, connect each to a different COM port (created by the Virtual Serial Port Driver), and try sending/receiving data. If properly set up, data sent from one port should appear on the other, mimicking a null modem setup.
In case you need a more detailed guide or alternative recommendations, the Sysadmin forum post might put you on the right path.
Don’t let the old tech snag get you down; it’s a pretty common issue with retro tech projects. Happy tinkering!
How can you emulate a null modem, huh? It sounds like you’re diving into some vintage tech fun! Here’s another way to tackle that without repeating too much from what @codecrafter mentioned.
Hardware Alternatives
- Loopback Plug: If you have a serial port available, you could make or use a loopback plug. Sometimes physical is just easier, especially if you’re working with really old hardware that might not play well with virtual solutions.
- Serial Bluetooth Adapters: You could look into converting the null modem setup to a wireless solution using Bluetooth serial adapters. It keeps things a bit cleaner and might be more practical for your setup.
Software Alternatives
- com0com: This is another virtual serial port emulator that can create paired COM ports to mimic a null modem setup. It’s open-source and widely used.
- Download and install it.
- Use the setup utility to create a pair of connected COM ports.
This might work better depending on any compatibility issues you’ve got with other software.
Detailed Steps with com0com:
- Download com0com from their official site.
- Install the software and open the setup utility.
- Create a Pair: Define the names of your virtual COM ports.
- Confirm and Test: Complete the setup and test using terminal applications like PuTTY.
Testing
- Terminal Software: Besides PuTTY, try RealTerm or HyperTerminal for Windows.
- Data Transfer Test: Open two instances, connect to each virtual port and start sending data back and forth to ensure everything’s working.
And for folks who need more information on virtual null modem emulation, check out the comprehensive guide on this Null Modem Emulator site.
There you go, you’re all set to revive that old project! Time to enjoy pretending it’s the ’90s again.
You could look into using socat if you’re comfortable with command-line tools. This might be a bit more technical and less UI-friendly than the virtual solutions already mentioned, but it offers great flexibility. Socat can create two bidirectionally connected virtual serial ports, effectively emulating a null modem.
Steps to Use Socat:
- Install socat using your package manager (for example,
sudo apt-get install socat
on Debian-based systems). - Use the following command to create two linked virtual serial ports:
socat pty,link=/dev/ttyV0,raw,echo=0 pty,link=/dev/ttyV1,raw,echo=0
- The
/dev/ttyV0
and/dev/ttyV1
act as COM ports that can now communicate with each other.
Pros:
- Free and Open Source: Socat is open-source and doesn’t cost a dime.
- Highly Configurable: Advanced users can fine-tune parameters for specific needs.
Cons:
- Steep Learning Curve: Not beginner-friendly, requires comfort with CLI.
- Lacks GUI: If you prefer graphical interfaces, this isn’t for you.
Comparing Solutions:
- Virtual Serial Port Driver: Easier setup with GUI; great for users shy away from command-line. However, it’s a paid solution.
- com0com: Free and relatively simple but may have compatibility quirks.
- socat: Highly flexible and open-source, but less intuitive for beginners.
Different projects and comfort levels warrant different tools, so consider your specific needs. All three methods get the job done but cater to different user expertise levels. Try out the one that suits you best!