Can Prop-2 debug port cause a reset?

[mmahrle]

I have several Prop-2s connected via their debug ports to a laptop (Windows 7).  The DB-9 on the Prop-2 is connected to the PC using a USB to Serial adapter (no, not the one EFX-TEK sells).  Communication is fine, but there is a strange effect that I'm trying to understand.

When the PC program (VB.NET) opens the COM port connected to the Prop-2, the controller displays all the signs of having been reset (same operations as when it is first powered up).  I don't really know what all is going on when the COM port object is opened.  My questions is whether there is a way that signals coming in on the debug port (e.g. flow control like RTS, CTS, etc) or some combination could reset the Prop-2?

[JonnyMac]

Yes, that can happen.  In fact, the IDE resets the BASIC Stamp so that it goes into identify mode and allows reprogramming.  The DTR pin is used for this purpose.  You'll want to disable it in your own programs.

[mmahrle]

Thanks for the prompt reply.  I figured it had to be something like that but I had never seen any documentation on the Debug port.