USB CDC Communication Problem

ljunior · Joined: 26 Apr 2011 Posts: 4 Location: Brazil

Hi,

I'm using CCS USB CDC implemented in a PIC18F4550 for communicating with a Visual Basic software. My system works fine for some time and then it crashes. The windows gives the following answers:

Run-Time error '8015':

Could not set comm state, there may be one or more invalid communications parameters.

Anyone can help me?

Ttelmah · Joined: 11 Mar 2010 Posts: 19539

Run time error 8015, means one of two things:

Two packages both trying to open one port.
Something is trying to change a port setting, that is not accepted.
The latter really doesn't happen. The CDC driver will accept all serial settings, even if it just ignores them. So I'd suspect the former.

I'd be suspicious, that you might have another 'background' program that thinks it can control the same com port as the one you are using.....
PalmPilot for example will do this. Or, a printer setup to use the com port.

Best Wishes