SerialConnection.BytesAvailable

From Xojo Documentation

Read-Only Property (As Integer )
IntegerValue = aSerialConnection.BytesAvailable

New in 2019r2

Supported for all project types and targets.

The number of bytes of data are available in the internal receive buffer.

Classes implementing the BytesAvailable property

IPCSocket
Serial New in 2005r1
TCPSocket

Sample Code

TextField1.Value = Str(Me.BytesAvailable)