Keep in mind that this all worked with both devices plugged in, prior to my uninstalling the root hub. With either USB to serial device unplugged, the return zero is non-zero and the ports are found. When I issue the command QueryDosDevice, the return value is zero, showing that there are no ports (of any kind). I rewrote the code that enumerates the ports, to add some diagnostic info. That did not help anything but the program that showed them all now only shows the active ones. Finally I enabled device manager to show hidden ports and uninstalled all the mid range ones that no longer exist. But with both plugged in, no enumeration is possible. Now the high port numbers are enumerated successfully, and work. Next I tried unplugging the USB to serial 4 port that gives the low port numbers. But selecting the correct one in the 15-18 group works. The program that uses these also enumerates the ports, but it showed all port numbers from 3 to 18. However enumerating them fails, BUT the programs that use the low ports still work as long as I don't try to change the port. Device manager now shows that the high ports have moved from 8,9,10,11 to 15,16,17,18. To my suprise they were now able to be seen by my program that enumerates the ports, and they work! Next plugged in the second USB to 4 port serial. Then tried plugging only the one with the low ports (3-6). I unplugged both of my 4 port USB to serial devices and rebooted. Short of reinstalling windows, I have no other ideas at present. I have the latest updated Windows 10 and it says I have the correct drivers, and that it is fully updated. Since then I have uninstalled all the root hubs, scanned, rebooted, and then done the same thing for each individual serial port. Another program does show the ports, but will not connect to any of them. That program can no longer find any serial ports, even though they are visible (and shown as working) in device manager. It enumberates the serial ports and puts them in a list for selection. But none of the ports work! One of the programs is one I wrote. The root hub and all the ports came back and all looked ok.
All my serial ports dissappeared, and scanning for new hardware did not restore them. The computer immediately wanted to be rebooted. THe first hub I uninstalled was the USB 3.0 hub. I was trying to figure out these problems, studying comments from Google, and came across someone that said it was a good idea to uninstall the USB root hubs and then scan for new hardware. They were all working but with an ocassional problem that I could clear with some work. I have 9 USB serial ports on my windows 10 computer. I have a lot of windows experience but this thing has me baffled.
0 kommentar(er)
