I’m trying to use one physical serial port with multiple applications at the same time. I heard about serial port emulators that can split a COM port, but I’m not sure which one to use or how to set it up. Has anyone done this before or can recommend software that works reliably? Any help would be appreciated.
When You’re Stuck With Just One Serial Port…
So picture this: you’ve got a device hooked up, and your trusty computer only offers a single serial port. But life throws you a curveball—you actually need that same stream of data to feed another program at the same time. Ever been there? Yeah, it’s awkward.
Let me save you hours of frustration: check out this serial port emulator. Seriously, with tools like that, you don’t have to scrounge for old adapters or swap cables mid-session. It’s like a “clone” button for your port—virtual ports get spun up, letting separate apps listen simultaneously without stepping on each other’s toes.
No wiring. No risk of Windows flat-out refusing to play nice. It’s made my test setups so much smoother, especially when logging and analyzing in two different pieces of software. Give it a try if you’re done with cable yoga.
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I’ve wrestled with this exact headache––one physical serial port, two (or, heaven forbid, MORE) apps clawing for data at the same time. Sure, serial port emulator software is a lifesaver (shoutout to @mikeappsreviewer for hammering that home), but let me throw a wrench into the love fest for a sec. Emulators like Virtual Serial Port Driver are great, but if you’re not careful, you can absolutely pummel your system with conflicts. Not every app is friendly with virtualized COMs. Some get confused or aggressively hog resources, especially legacy industrial programs.
If you want a straightforward breakdown:
- Install the Virtual Serial Port Driver.
- Create a virtual “splitter” (they call it a port splitter) so your actual COM1 gets mirrored as virtual COM2 and COM3.
- Point one app to COM2, the other to COM3—they both get the data stream from the real port.
But, here’s where it gets messy: latency. I’ve seen some timing-sensitive gear wig out (think GPS receivers or motor controllers that care about handshake lines). In those cases, emulation isn’t magic. And don’t even get me started on the wonky licensing models or how some add “trial” popups mid-test. (No, I’m not still salty about a bricked night shift, why do you ask?)
Alternative? Try hardware splitters only if your devices (and wallet) can handle it, but yeah, software like creating reliable virtual COM port connections is usually way less painful.
Just nitpicking, but sometimes less is more—if you can redesign the workflow so only one app needs direct access, you’ll have a much easier time. Otherwise, buckle up: emulators are about as good as it gets, quirks and all.
I might get roasted for this, but honestly—software splitting a physical COM port isn’t the magical, always-flawless fix folks want it to be. Sure, like @mikeappsreviewer and @chasseurdetoiles said, Virtual Serial Port Driver or similar tools will basically “mirror” your data stream across fake virtual ports, letting multiple apps grab the same data. Works? Most of the time… at least if your setup is straight-forward, timing isn’t mission-critical, and you aren’t running some decades-old industrial software that throws a fit the second things get “non-standard.”
But let’s cut through the hype a bit: these emulators can introduce subtle issues. Data collisions, handshake/flow control weirdness, and, in some cases, random drops if your apps try to control the port instead of just passively reading it. I’ve seen it with lab stuff where one program wants exclusive low-level access. Fun times. Don’t even get me started if you try to deal with RS-485 or strange baud rates—sometimes the emulation just doesn’t keep up.
If your two (or more) client programs just need to read the same data (not writing or toggling control lines), it’s probably fine. For anything “active” or hardware-level, I’d say figure out if you can workaround with a single collector-app, or see if your hardware supports some kind of hardware splitter (less flexible, more reliable, usually more expensive).
All that said, setting up most of these emulators is dead simple: install, run, set up your virtual splitters (say, clone COM1 to COM2/COM3), point your apps accordingly and off you go. Want to jump right in? Here’s where you can learn more about setting up a virtual serial port splitter.
TL;DR—software port splitting can be a lifesaver, or it can open a wormhole of random little failures. Test before you trust it in anything critical, and keep your workflow as simple as possible if you can.
Here’s the real talk: splitting a single COM port for multiple apps isn’t as seamless as folks hope, but it is doable with the right expectations and tools. Virtual Serial Port Driver is a go-to for many because it’s stupid-easy to set up—install, configure which physical port you’re duplicating, create a couple virtual ports, and point your apps there. Boom! Data mirroring magic.
Pros for Virtual Serial Port Driver:
- No extra hardware or physical adapters needed
- User-friendly UI; even newcomers won’t get lost
- Stable for most “read-only” scenarios (like two apps both logging GPS or scanner data)
- Tons of config options if you want to finetune
Cons:
- Not flawless for advanced stuff. If either app tries to take “ownership” of the port or play with control signals, things can get weird—dropped packets, control-line confusion, and mystical app errors.
- Some anti-virus programs freak out at the driver install (you may need to whitelist).
- It isn’t free. You pay for that reliability and UI polish.
Competitors exist (like the ones mentioned above), and some folks swear by open-source alternates such as com0com or Serial Port Splitter. com0com can get you there for free, but setup is way more tedious and documentation sparse. If you’ve got time and don’t mind registry tinkering, give those a look.
If you want bulletproof reliability for industrial gear, hardware splitters are safer (but obviously, they cost more and don’t do control-line magic). For most hobbyist or light testing use-cases though? Software is fine.
Little trick: keep all apps as “readers” only whenever possible. The second you need to write or toggle DTR/RTS, software solutions start to sweat. And always, always test with your actual workflow before trusting it for mission-critical stuff.
TL;DR: Virtual Serial Port Driver is great if your needs are basic-to-moderate, but double-check compatibility if you’re pushing boundaries. If things get flaky, remember—sometimes old-school hardware still wins.