It works directly from the EOS camera control program that comes with the camera.
You connect your camera via the supplied cord and then turn the camera on with it set on manual.
On the remote control software you make the exposure time "bulb". There is a little icon that brings up a very simple controller for interval shooting and bulb exposures. I make it 300 sec and start it. No need for any other connection to the camera. The only other settings I fiddle with are RAW, ASA800 (or what you like) and change the white balance from auto to daylight.
Just be very careful not to stuff it by breaking the connector off as I did 2 nights ago. See
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