Hi,

I really don't know if inversion can be achieved using the default serial class. You can connect the LED to the positive rail and the TX output via a limiting resistor. This give you a straight out. Positive rail is not available on the RS232 connector. So use the DTR line and flip it (Set High) in VB before starting the communication. This gives you a steady positive supply on DTR (8-12 volts). Connecting the LED to the ground inverts the signal. Take care of the LED polarity at the TxOut in both the cases.