Random latency between set_output_pwm and get_output_pwm

[Humi (Roman)]

Hi all. Pixhawk 6x, ArduPlane 4.5.7. I’ve noticed latency in the lua script of mine, sometimes I can see a 50 ms and sometimes ~1 sec latency in debug messages between nil pwm value and value I set in set_output_pwm. This latency randomly changes when rebooting pixhawk. Is this latency in get_output_pwm function or real latency between executing command and setting servo pwm? Script example and screenshots of latency in messages are attached.

local PARACHUTE_SCRIPTING_CHANNEL = 109;
local PARACHUTE_SERVO_CHANNEL = 27;
local time_to_set_servo = 10000; --milliseconds
local timeout = 0;

local PARACHUTE_PWM_PARAMETER = Parameter();
PARACHUTE_PWM_PARAMETER:init("CHUTE_SERVO_ON");
local servo_parachute_release_pwm = PARACHUTE_PWM_PARAMETER:get();
local curr_time = 0;
local MAX_SERVO_NUMBER = 16;

local TEMP_PARAMETER = Parameter();
local PARACHUTE_SERVO = Parameter();

local function_complete = 0;
local PWM_message = 0

----------------------------------------------------------------------

function update()

	curr_time = millis();

	setServo();

	return update, 50
end

----------------------------------------------------------------------

function setServo()
	if (timeout == 0) then
		timeout = curr_time;
	end

	if (curr_time - timeout >= time_to_set_servo and function_complete == 0) then
		PARACHUTE_SERVO:set(PARACHUTE_SCRIPTING_CHANNEL);
		gcs:send_text(7, tostring(millis()) .. " attempt to set servo channel to scripting");
		if (PARACHUTE_SERVO:get() == PARACHUTE_SCRIPTING_CHANNEL) then
			gcs:send_text(7, tostring(millis()) .. " servo channel set to scripting");
		end
		timeout = curr_time;
	end

	if (PARACHUTE_SERVO:get() == PARACHUTE_SCRIPTING_CHANNEL) then
		SRV_Channels:set_output_pwm(PARACHUTE_SCRIPTING_CHANNEL, servo_parachute_release_pwm);
			if (SRV_Channels:get_output_pwm(PARACHUTE_SCRIPTING_CHANNEL) ~= nil and PWM_message == 0) then
				gcs:send_text(7, tostring(millis()) .. " Parachute servo PWM set to " .. tostring(SRV_Channels:get_output_pwm(PARACHUTE_SCRIPTING_CHANNEL)));
                PWM_message = 1;
            end

			if (SRV_Channels:get_output_pwm(PARACHUTE_SCRIPTING_CHANNEL) == nil) then
				gcs:send_text(7, tostring(millis()) .. " Parachute servo PWM is nil ")
			end
		function_complete = 1;
		timeout = 0;
	end

end

----------------------------------------------------------------------

for i = 1, MAX_SERVO_NUMBER do
	TEMP_PARAMETER:init('SERVO' .. tostring(i) .. '_FUNCTION' );
	if (TEMP_PARAMETER:get() == PARACHUTE_SERVO_CHANNEL) then
		PARACHUTE_SERVO:init('SERVO' .. tostring(i) .. '_FUNCTION');
	end
end

return update, 1000