If I understand correctly exposures longer than 30s can be made via either a connection of some sort to the remote connector or the camera or internally via eosremoterelease property.
gphoto2 --list-allconfig confirms that the eos 760D has that property so I expect the infi_gphoto_ccd driver to be able to manage aver 30s exposures directly via USB.

But it does not work on my 760D. The indi panel shows a "shutter release port" which is green and set by default to 7624.
So on requesting an exposure longer than 30s, the driver tries to trigger/communicate on that non existent port and of course fails.
Everything predefined works well up to 30s.
Any idea what I am missing ?
(I have compiled a freshly pulled version of indi-gphoto-ccd)