Sending API frames to same XBee via serial results in "self-addressed" (0x23) status

Since we’re running out of radios, I’m trying to connect some things via serial/USB.

But when I try to send a frame to the address of the transmitting XBee, it returns the status 23, “Self-addressed”.

The meaning is self-explanatory, but is there a way to make this work?

Thanks in advance.

You are trying to send a data packet out via the DI line that is for that device. No that is not going to work.