Cannot open com port

[Wolleee]

Hi all,

maybe not entirely sure if this is a labview question, but i was using labview when it happened.  I am using labview to open and run a batch file using a COM connection and an FTDI RS232 to USB.  Now i believe that portion of the code runs smoothly, ive tested it out and it worked at one point.  After using an instr property node to check if port is open, which i now know cant be used on non ni devices anyways, it will not open to run the batch file.  I have run it from command prompt and i get a communcation port cant be open error.  Now i moved one of these devices from  COM16 to COM2 and it works perfectly now, but the other one wont work at all and why should i have to change port numbers? any tips or troubleshooting advice?

[tyk007]

Presuming you are using Windows - there are a number of quirks with virtual com ports with USB. It is quite possible for said ports to effectively get "locked up" and unusable until the PC is rebooted. I've never been able to isolate the series of events that causes this.

[Wolleee]

So this is quite bizzare, because i have restarted the computer twice now and i can still use the port in tera term.  I even uninstalled the port and reinstalled it.

[Wolleee]

Just in case anyone out there runs into the same problem, i followed this link here, uninstalled all com ports, then reinstalled com ports and is now functioning properly. But it seems that my port 18 which was not working before is still not working.

http://theitbros.com/how-to-delete-com-ports-in-use/