Digirig on Yaesu FT-65

Hi All! I need a little help connecting my FT-65 to the Digirig with the original cable.
I have my Digirig connected to the USB. (Report Com 5)
I connect the original cable to the Digirig top port(Audio)
As soon I connect my FT-65 start to transmit.
Am I doing something wrong? or I have a defective cable?
Thanks in advance,
Jorge VE3EAD

This has to do with RTS signal being used for flow control of the serial port. The settings need to be unchecked in the digital modes software before radio is connected to Digirig.

From getting started guide:

Software Setup – PTT

Digirig offers a hardware PTT switch controlled by the RTS signal of its serial port. Alternatively, transceivers supporting serial control interface can use CAT commands for keying up the radio.

In the digital modes software look for the configuration screen pertaining to PTT settings. There, choose the PTT by RTS option, selecting Digirig’s COM port as the source of the signal. This port selection is separate from rig control configuration. In some software packages you may need to install an additional PTT module to enable this option.

To prevent unexpected transmission, disable any serial port’s settings related to hardware flow control or handshake. This includes any non-PTT related options mentioning RTS, CTS, DTR signals.

With the audio and hardware configured correctly you should be able to operate digital modes regardless of serial CAT control availability. Without the optional CAT control you will have to manually tune your radio to the target frequency and set modulation, filters etc.