Multiplex 4000 More Programming Questions
You can carry on using control reversing if you want as long as you work through all the effects it has downstream of the control. A control is at the top of the stream so everything is downstream of it and will be affected. But if you miss one of them, you get the sort of problem you ran up against and it's guaranteed that you won't notice it until you are in flight.
Since the servo is at the end of the stream there is no further downstream to affect, so altering direction at the servo has no other effects and therefore I feel safer doing that. Thanks to Multiplex software, each input at the servo is independently set for its direction, rather than just some sort of global direction for that servo. So for example if aileron and flap and spoiler are input to your ailerons, each one of those inputs can be reversed without having any effect on the direction of the other inputs into the servo. Go to menu 1, servo, travel/curve, choose the input (there is no choice if servo is assigned direct to a single control rather than to servomix), activate the travel value by pressing bottom right triangle button, then press R to reverse the direction. You will see the graph swap its slope around as you do it.
The reason that the trims don't reverse with the controls is that trims are actually proper independent controls in their own right just like the two big sliders E and F, they are not simply slave pots wired into the control stick. The full range of assignable controls is not just A to M, at the end of the assign controls menu you will find TA to TD waiting to be assigned to a function. Like all controls they are not automatically assigned to a function, however they do default to being mixed into the stick next to them at 30%. It's the only time in the Profi radios that mixing takes place at the control level instead of the at the servo level. That is why if you reverse the control you get the problem. Reversing the control reverses the stick effect, but the trim is an independent control being mixed in a particular direction and it will continue to mix in that direction until you go into its mixing software and reverse it. The trim's mixing software is menu 1, controls, TRIM TRAV. The value shown is the mixing rate and the +/- shows the direction of mix. I find the default mix 30% a bit coarse so my master model is set to 20% except for throttle.
This method allows the trims to be used as separate controls. Someone on RCU once said he wanted a servo to control a proper elevator trim tab using its own channel, but working off the elevator trim lever which in turn would have no effect upon the elevator servo, could any radio do it? Of course the reply was the Mpx 4000 can. Set TRIM TRAV to zero% so it does not affect the ele servo, then go through the standard process to assign a control and servo. Assign the relevant T for your mode to Aux 1 function and assign the trim tab servo to aux 1. For some other application, leave TRIM TRAV at normal value so it works on the main servo, aux 1 and its servo could be used for something utterly different to the main control with its own travel curve. Or rudder trim could be assigned to aux 1 but no servo assigned, and aux 1 mixed to the servos for twin throttles so that rudder trim impacts the separate throttle values. The creation of trims as independent assignable controls allows for all sort of possibilities for the creative and adventurous.
Harry