When I connect to the Omega2 via serial port, I get a ton of these errors, at a frequent rate, maybe 1 per minute.
Doesn't seem to have any relationship to what I'm doing; they continue to build up when I'm idle.

What doe it mean?
Where does it originate?
How can I fix it or silence it?

Thanks!

@crispyoz Well, having a complete, functioning cable is the key!
Amazon one-day to the rescue.
As soon as I plugged it in (still powered through the USB-A port) it registered as COM3.
Unplugged the -A and brought up the CLI in PUTTY,,,

Thank you for the patient assistance!

@crispyoz Sorry, brain fart!
Comes from unboxing two devices the same weekend...
I ordered an RP-400 about the same time. Pretty nice package, with a complete Linux box in a compact keyboard. That had all those accessories...

@crispyoz Hmm. Now I think of it, I may have used a cable I already had. If so, it's possibly a "charge only" cable.
Otherwise, no Unknown Devices, and definitely an Expansion Dock. The UART/USB chip is present.

Thinking about "bundles", when I ordered the Omega and the Dock, add-ons were the 40-pin GPIO cable, 32GB SDCard, and microSD.
The SDCard has the Rasperry PI logo; is that a system distro, for re-flashing?
And what is the microSD for ?

@crispyoz No, I'm not messing with the DB9 serial port, that's clearly not what needs to connect to the Omega.
I am using the Omega-supplied USB-A-to-micro USB cable that came with the Omega and Expansion Dock.

I suppose it's possible the cable is bad, but it does provide power fine. I'll try another cable, for sure.
Any idea how to tell if there is a dock problem?
I'm most concerned about the PC not registering the USB device and creating a new COM port at this point.

Thanks,
Dave

@jossvall Yes, I understand the RS232 vs. TTL issue!
I was expecting to find the CP2102-based COM port, but it doesn't show up in Device Manager.
No Unknown Devices, either.

@jossvall Well, yes.
To clarify, I started out using the micro USB on the Omega expansion dock.
I misunderstood, believing that I needed to connect the PC USB to the USB-A jack, to use the serial port for command line direct access.
With the USB-A cable or without, I can't get a CLI prompt using COM1 at 115200 baud.
No problem connecting over the network to the Omega, but since I want to modify the web server, I don't want to do that without the direct port access.

@crispyoz I completely misread that! Thanks for the correction.

Now, any ideas why I can't find a new COM port?
The PC I'm using is a relatively new one, from an Amazon upgrade vender.
It has a 9-pin serial port connector, but I've never verified if it's actually implemented. Device Manager shows only COM1 (and no reference to CP2102), and connecting to COM1 with PUTTY at 115200, I don't get a CLI prompt, or anything else. I suspect it's talking to the DA9; maybe tonight I will jumper Tx to Rx to verify that.

I am trying to connect to my Omega2 (on Expansion Dock) from a Windows 10 PC.
Downloaded and installed the CP2102 driver, apparently successfully.
Downloaded PUTTY, installed fine.
Had to search a bit, but located a USB-A Male-to-Male cable.
The Omega2 is powering off the USB-A port (I accidentally dislodged the micro-USB, and it stayed up), but Windows will not register any USB device when I connect them. Only shows COM1, already on the PC. No CP2102, or COMx for x>1.

Any thoughts as to what's wrong?
Do I need some sort of USB crossover cable, with Tx and Rx swapped?

@crispyoz Thanks for all of that. The docs link was indeed helpful.
I realize Omega uses a stripped-down Linux distro, but it's been donkey's years since I did any real work in Unix or even Linux , and never any Web development under them.
Now, off to learn more PHP... I can see it's superior for IoT, which is where I'm headed!