Parameters that don't show up in QGC

I’m doing some detailed work with parameters right now and could use some input. I noticed that there are parameters in the full parameter reference that are not in the QGC list. For example this one.

CA9685_FUNC2 (INT32) PCA9685 Output Channel 2 Output Function

Comment: Select what should be output on PCA9685 Output Channel 2. The default failsafe value is set according to the selected function: - ‘Min’ for ConstantMin - ‘Max’ for ConstantMax - ‘Max’ for Parachute - (‘Max’+‘Min’)/2 for Servos - ‘Disarmed’ for the rest

Values:

  • 0: Disabled
  • 1: Constant Min
  • 2: Constant Max
  • 101: Motor 1
  • 102: Motor 2
  • 103: Motor 3
  • 104: Motor 4
  • 105: Motor 5
  • 106: Motor 6
  • 107: Motor 7
  • 108: Motor 8
  • 109: Motor 9
  • 110: Motor 10
  • 111: Motor 11
  • 112: Motor 12
  • 201: Servo 1
  • 202: Servo 2
  • 203: Servo 3
  • 204: Servo 4
  • 205: Servo 5
  • 206: Servo 6
  • 207: Servo 7
  • 208: Servo 8
  • 301: Offboard Actuator Set 1
  • 302: Offboard Actuator Set 2
  • 303: Offboard Actuator Set 3
  • 304: Offboard Actuator Set 4
  • 305: Offboard Actuator Set 5
  • 306: Offboard Actuator Set 6
  • 400: Landing Gear
  • 401: Parachute
  • 402: RC Roll
  • 403: RC Pitch
  • 404: RC Throttle
  • 405: RC Yaw
  • 406: RC Flaps
  • 407: RC AUX 1
  • 408: RC AUX 2
  • 409: RC AUX 3
  • 410: RC AUX 4
  • 411: RC AUX 5
  • 412: RC AUX 6
  • 420: Gimbal Roll
  • 421: Gimbal Pitch
  • 422: Gimbal Yaw

I never noticed this parameter before so I think it may be new to PX4 1.13.3 which I am using. At any rate, what does this parameter do and when should I use it? Also, this parameter does not show up in the .params file that I downloaded from QGC,

Thanks,
Joe

PCA6985 is a 16 PWM board with Arduino or Raspberry PI, you could extend number of output of you flight controller.
I never used it, no idea how exactly it works.

@Joseph_Marrone driver/pca9685_pwm_output: bugfixs & QGC integration & support outputting in duty-cycle mode by SalimTerryLi · Pull Request #21528 · PX4/PX4-Autopilot · GitHub this might help you.