Is there any way to monitor/log all the data (the raw bytes) going through a COM port while a program is using it? I’m using Windows 8.
Details:
At work we have an old solar inverter. It outputs data through a serial port and I talk to it with a proprietary program from the manufacturer. I want to figure out the protocol so I can get an Arduino or similar to talk to it and log data, instead of having to keep a power-hungry Windows PC on the whole time.
Get the Arduino and have it monitor the output from the COM port before passing it on to the end device. Otherwise I’m sure there’s software to do this, I just have no idea what it would be because I haven’t seen a COM port actually used for a long time. But I do have a four port serial interface card that was in perfect working order sometime in the late 80s in case you need something like that.
I just googled the words COM port monitor and got a scant 42,100,000 results. So there are some out there. Included in the results were many with screen shots, and many of those somewhat resembled WireShark displays.
Depending on the devices on either end, I’ve got a simple splitter to work before.
If you need to monitor traffic from both devices, you’d use two ports on the interception PC.
Then install a serial monitoring program and run two instances for the two ports.
Previous thread on the subject, but Windows 8 wasn’t around yet.
You need what is known as a Protocol Analyzer.
Look at the offerings from Saleae.
:smack: I totally forgot I started that! Lol. The same problem keeps rolling around, apparently.
I found software to do this and it seems like that might work. I’ll report back if it does this time around. And hopefully remember for the next half-decade.
Don’t forget that the work may have been done already
eg
Is the invertor mentioned at ? (and if not, is a relative or derivative mentioned ?)
http://whirlpool.net.au/wiki/solar_software
I love you :o
We might be able to get this running on Raspberry Pi using one of the Linux tools. If not directly, the entire communication protocol has been made available in C.
It was an Aurora PVI-3600, discontinued, but it should still speak the same protocol since the official software still works with it.
Thank you so, so much 
I just looked up Arduino in Wikipedia, and now have even less idea what it might be than when I first saw the word in the OP of this thread. 
It’s a basic, very cheap computer, with connections for various types of input and output.
You supply the input devices, the output devices, and the software to process the data between.
Fun for geeky do-it-yourselfers.
Thank you again! That’s exactly what we ended up doing. Got a Pi, put Linux and Aurora Monitor on there, and four hours later, the data is streamed live to pvoutput.org. Your post saved us dozens of hours of work.