Help needed-configuring RS-232 (problem w/DNC only) on a new PC...I'm stumped!

[Brian]

Man, I hate asking for help on something that I've done a number of times successfully, but I'm stumped at this point!

I'm getting a new Dell Precision 3660 (Win 11) configured, and I'm getting down to the short strokes, but have hit a snag and am outta ammo as they say. I'm using Cimco Edit 2023 to upload/download to a Fanuc18M mill using RS-232. Everything worked well on the previous PC (another Dell, a Precision 3260 running Win 10) using Cimco Edit 8.

I have configured Cimco on the new PC with identical port settings, etc. The new PC didn't have a serial port on the motherboard, so I added a Sunix serial card, and installed it into a PCI slot and installed the Dell-provided driver. I AM able to upload/download w/o issue but am having trouble with DNC. I can initiate the file transfer, but it will generally send a few lines and then the controller will hang, without an error. I vaguely recall encountering this issue before when setting up the previous PC, and resolved it by tweaking the FIFO buffer settings in Win 10. I have replicated the previous PC's setting as closely as I can (though there are some differences, which I assume have to do with differences between Win 10 and Win 11, and the add-on serial card in the new PC). Yes, all of the obvious stuff has been successfully configured-baud rate, stop bits, parity, etc. After setting this up on the old PC last time I figured I'd make it easy for the next time and document it all thoroughly with pics & notes.

Has anybody here encountered issues with serial comms in Win 11? Ideas to resolve them?

Luckily, upload and download works well, but somehow DNC is beyond my grasp at the moment! My hunch is this has something to do with the FIFO buffer settings, but I still haven't got the winning combo-woof!

And with that-it's now officially "beer-o-clock" Sorry for the ramble-jeez.

Cheers, Brian