By RogerInHawaii
I have the APC220 RF Communications kit. I'm looking at the pins on the RF board and comparing them to the pin holes on the socket of the USB-to-Serial board, and they don't match. In particular the TXD pin on the RF Board plugs into the RXD hole in the socket, and the RXD pin on the RF Board plugs into the TXD holein the socket.

Is that right? That seems illogical to me. Shouldn't the TXD pin plug into the TXD hole and the RXD pin plug into the RXD hole??
By Hector
Hi Roger,

TXD- transmitted
RXD - Received.

So the "Transmitted" info goes to the "Received" pin...

That is why they are flipped. But that is not always the case. Unfortunately there is no one standard. Just make sure all the other pins line up, namely the GND and Voltage pins. So long as those are not flipped you will be safe.