OutbufferCount Retrieves the number of bytes in the transmit buffer. MSComm32 and SComm32 have the same syntax and functionality. Syntax:- value = SComm1.OutbufferCount value:- A numerical value indicating the number of characters/bytes in the receive buffer.   Remarks. This property is primarily a "Read" property allowing you to retrieve the number of bytes in the transmit buffer. The only value that can be 'written' to this property is 0 (zero) which can be used to delete all data from the transmit buffer.