Servo commands being sent when arming

I am using a magnetic grapple, which functions with servo (PWM) commands of 1900, 1500, and 1100. I can energize and de-energize the grapple prior to arming by either sending servo commands from the servo menu, or by using CH7 tied to the grapple commands.

The problem comes about when I try to arm the aircraft (X8). Everytime I arm the copter, the grapple first commands 1900 (hold) for a few seconds, then commands 1100 (release) for a few seconds, then back to 1500 (neutral). Of course, this releases my payload before I can even takeoff.

Anyone have any ideas about why Copter would be sending servo commands immediately after arming? My guess would be some kind of servo test, but I’ve not seen that before with this setup.

I’m running with Copter 3.5.5 on a Pixhawk 2.1.

I really need to get this problem solved for a demonstration we’re planning next week. Any help would be appreciated.

Cheers!

Why are you using a servo function instead of the EPM gripper function ?

Amilcurlucas,

EMP gripper function doesn’t work. However, that is completely besides the point. The problem isn’t with the function. The problem is with the commands that are being sent immediately after ARMING the aircraft.

Does anyone have any idea why Copter would be sending the commands as soon as the aircraft is armed?

EMP gripper function doesn¢t work. However, that is completely besides the

Can you say why the gripper function doesn’t work?

point. The problem isn¢t with the function. The problem is with the
commands that are being sent immediately after ARMING the aircraft.

Does anyone have any idea why Copter would be sending the commands as soon
as the aircraft is armed?

Have you replicated this in SITL? If so, could you spell out the steps to
reproduce, please?

Hi, Peter.

I can’t say why the gripper function doesn’t work. I’ve been using the EPM for a while and I’ve only had success with Auto mission using the servo commands. I’ll try again this afternoon when we fly, and see what the logs show.

I have not used SITL.

Cheers!