# Issue with DShot ESC's with VTOL airframe

**URL:** <https://discuss.px4.io/t/issue-with-dshot-escs-with-vtol-airframe/23961>\
**Category:** PX4 Autopilot\
**Created:** [August 27, 2021, 1:43pm UTC](https://discuss.px4.io/t/issue-with-dshot-escs-with-vtol-airframe/23961 "2021-08-27T13:43:09Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![GalDa](https://discuss.px4.io/letter_avatar_proxy/v4/letter/g/ecd19e/32.png) [@GalDa](https://discuss.px4.io/u/GalDa)\
**Post date:** [August 27, 2021, 1:43pm UTC](https://discuss.px4.io/t/issue-with-dshot-escs-with-vtol-airframe/23961/1 "2021-08-27T13:43:09Z")

</div>

Hi all,

I think there an issue when trying to work with VTOL vehicle and DShot ESC’s.

Running with generic quadcopter frame I can mange to get my ESC’s work in DShot300 configuration and it’s working well with the Pixhawk orange Cube running the latest PX4 V1.12.1.  
The ESC’s are connected to the Pixhawk AUX outputs and the configuration set as follow:  
SYS\_USE\_IO=0,  
DSHOT\_CONFIG=DShot 300

When trying to work in the same hardware configuration with different airframe - Quadrotor X Tailsitter it seems that the I can not activate my ESC’s using the DShot300 configuration (or any non PWM one),  
using DSHOT\_CONFIG=Disable ( use WM/OneShot ), PWM configuration works well so it’s not a mixer problem.

So I dug a little dipper and I found that it’s related to the VTOL variable send to the different constructors in the `rc.vtol_apps` file, specifically:

```auto
MulticopterRateControl::MulticopterRateControl(bool vtol) :
	ModuleParams(nullptr),
	WorkItem(MODULE_NAME, px4::wq_configurations::rate_ctrl),
	_actuators_0_pub(vtol ? ORB_ID(actuator_controls_virtual_mc) : ORB_ID(`actuator_controls_0`)),
	_loop_perf(perf_alloc(PC_ELAPSED, MODULE_NAME": cycle"))
{
	_vehicle_status.vehicle_type = vehicle_status_s::VEHICLE_TYPE_ROTARY_WING;

	parameters_updated();
}

```

What is the difference between `actuator_controls_virtual_mc` and `actuator_controls_0`?  
Is it a bug in the firmware?

Thanks, Gal