6.4.3. Focus controller

Once you’ve build your custom cable, you can modify your console JSON configuration file and add:

"endoscope-focus": {
    // replace the MTML part in the filename by
    // whatever controller you're connecting the cable to
    "io": "io/sawRobotIO1394-MTML-dv-endoscope-focus.xml"

The example above assumes that:

You’re using the dVRK software rev 1.6 or above
You have connected to the camera focus cable to the MTML controller. If you’re connecting the endoscope focus unit to another controller, and you can’t find the corresponding configuration file in sawIntuitiveResearchKit share/io, feel free to create one and contribute it back to the community
You have the da Vinci foot pedal connected with the Camera +/- toggle pedal properly working. You can check in the Qt graphical user interface, under the IO/Buttons tab.

At that point, you should be able to control the camera focus using the foot pedals. When pressing the +/- pedal you should:

See the focus change
See the “Focus In”/”Focus Out” LED turn on/off on the vision cart
Hear the motor on the camera head

The da Vinci Focus controller uses joint limit switches to stop the motion when the focus mechanism reaches a limit. When this happens, the motor will stop and the “Focus In” or “Focus Out” LED will start blinking.