Ok, instead of the message box, add a pair of edit boxes to the form.

Then try this in each OnComm method:

thisform.edit1.Value = thisform.edit1.Value + this.input

and

thisform.edit2.Value = thisform.edit2.Value + this.input

in the second control.

>for testing I have =MESSAGEBOX(STR(This.commPort)) in OnComm for both.
>Only is responding.