Hey there folks. I am trying to get serial output from one machine to another via two USB-to-serial adapters (one 1 Port FTDI USB to RS232 Null Modem Adapter plugged into the host - serial: ICUSB232FTN, and one FTDI USB to Serial RS232 Adapter Cable with COM Retention (FTDI USB UART Chip) - serial: ICUSB2321F).
Both the host and guest are running Windows 11, and have seemingly up-to-date FTDI drivers installed. Where we run into problems is in transmitting debug logging data from any sort of kernel mode driver; even though this type of serial logging usually succeeds on KVM/VMware boxes. On bare metal, the TX/RX lights don’t even flash, though when connecting the cable between two PuTTY instances on both machines, we are able to see output. Any ideas as to why this might be? We’ve thoroughly investigated the device configuration from within Device Manager, and let PuTTY setup the port before executing OUT instructions within the kernel, but to no avail.
Oh and it may be worth mentioning: it doesn’t seem as though putting the device into loopback mode worked to read in data transmitted to the port.
Thanks! Hope all you guys are having a great start to the week
Thank you for posting on our StarTech.com Community forum!
I would like to make sure I am getting a full understanding of the scope of your use case and issue so I would like to ask some additional questions if you don’t mind:
Have you used other USB serial adapter brands/models on these same computers for this exact same task that do work in this same configuration?
What is the tool or utility/software being used for this serial logging?
To confirm, you are able to get serial communication back and forth between systems using a PuTTY instance on each with this same configuration, but just not when doing this Kernel-Mode Debugging over Serial?
Do you get any indication of error at all? Any error messages?
Have you tested this on various different bare metal setups all with the same result?
Hopefully with some of these details I am able to get a better idea of your configuration and process and try to find a solution.
I would also recommend as an option to contact one of our Technical Advisors via our Live chat which you can find on our website who would be able to assist with some live assistance and troubleshooting.
We have used some other USB serial adapters in the past (I believe) for collecting logs out of this embedded software, though I think the logging has mostly been collected–as of late–from crash dumps and DMA circular buffers.
Well we had used PuTTY as a test to see if we could get something simple working, but the software we’re having trouble with is proprietary to the company. If need be, we could share partial builds of it or the code with someone from your company if you’d need to take a look at it.
Yes, though know that we just used PuTTY as a test to see if we could get logging to work under any circumstance. Our goal in using the cables is to receive debug logs that are output to the serial port and not to do any sort of complex serial-based debugging.
I have not yet inspected the line/modem status registers, so I don’t know what they might report (which would be implementation specific to the FTDI driver that was installed when the cable was plugged in), but no: at this time there have been no reported errors.
The problem reported seems to be unique to the cables used, but it’s certainly possible we just aren’t communicating our logging through the serial port in a way the FTDI driver or hardware permit.
Thank you for the tip about contacting a Technical Advisor. I wasn’t able to find a link to the live chat on your homepage. Would you be able to link to that? My apologies.
Thank you regardless, and I do hope this message finds you well
Hi @cal and thank you for this information. Also, sorry about this delayed response.
First, for our Live Chat I do not have a direct link as it is a chat widget. If you go to www.startech.com you should see the “Chat” widget generally located in the bottom right corner of the page:
Now unfortunately any custom or proprietary software would not be something we would be able to dive too deep into and we generally do stick to fairly standard Serial applications (such as PuTTY) for testing/troubleshooting and to confirm the device itself is working.
As long as this is being used within an appropriate supported OS version and the software you are using it with is leveraging the proper driver, calling the correct COM number assigned to the adapter within the OS, and initiating the proper Serial settings (Baud rate, etc.) I would expect it to work. However when custom software is being used it would be very difficult to troubleshoot and confirm if/what in that software could be impacting the functionality.
Still, do please feel free to reach out to our Technical Advisors using our Live Chat and we will be happy to discuss this further.
