lnComPort = 1 && actually derived from an app property set at login with This.oleComPort && THIS applies to the form the control is on .CommPort = lnComPort .InputLen = 0 .PortOpen = .t. .Output = Chr(255) && or some other arbitrary character string .DoVerb() .PortOpen = .f. EndWithThe DoVerb was the only method I thought would send the Output string to the com port. There were some values that could be passed with DoVerb [0 - default, -1, etc.], but none of the definitions in the DoVerb help adequately explained what each really does as it would apply to this control.