Wiki page recommends to use VFPCOM. VFPCOM dows not work with VFP 7.
So I used EVENTHANDLER() to attach my custom OnComm() event.

I need to access to MSCOMM properties such as .input, .output
from attached event handler but this is impossible.
How to access control properties from binded event ?

>>I need to place a code to mscomm OnComm() event.
>>I have found that if I place to OnComm() event in a separate class and
>>add an instance of this class to form using
>>
>>thisform.NEWOBJECT('oCom', 'mycomm','mycomlass.vcx')
>>
>>OnComm() event does not fire!
>>
>>However, if I place a MSCOMM OLEControl directly to form and place code to its OnComm() event, OnComm() event fires!
>>
>
>A known issue. Sergey is correct - it will work dropped on a form. Go here: http://fox.wikis.com/wc.dll?Wiki~MsComm32~VFP and you will find the answer.Wiki