BBB with serial communication at baud 230400

I am using a BBB to connect to some third party hardware. The hardware serial communication at baud 230400 (8/N/1 - bits/par/stop).

I didn’t use the J1 port since it only maps Tx/Rx/Gnd by default.

I need Tx/Rx/Gnd/DTR/RTS/CTS.

To try and accommodate this, I purchase a cape (USB-2COM-BB) from While the cape works, I am not sure it can properly communicate at the baud I need, or maybe, it isn’t passing the rts/cts properly or I need a debian patch?

With all the wires connected, my SALEAE logic tells me the TX back to 3rd party hardware is 9624 (makes no sense). My software properly sets the baud rate.

I am thinking the cape is not working properly. Can someone explain how I can utilize the native serial port on the BBB to accomplish this (key part the need for RTS/DTR/CTS).

I am using the default debian from the BBB and I have the latest C rev.

Thanks in advance!