Trim wheel follows autopilot?

[dmahr]

Hi,

I have a trim wheel with stepper motor and magnetic encoder. It works fine, both manually and by trim switches.

When in autopilot mode the wheel is moved by the flight director - in the Sim.How can I get information about the FD commands to let my trim wheel follow? Are there any FSUIPC offsets which show the target trim position? All I found are some lvars which are airplane dependant. This is uncomfortable and not every plane has suitable variables. 

Many thanks for any hints.

Detlef

[John Dowson]

29 minutes ago, dmahr said:

Are there any FSUIPC offsets which show the target trim position?

Just search the FSUIPC Offset Status manual - for elevator trim, see 
    - 0BC0: Elevator trim control input: –16383 to +16383
    - 0BC2: Elevator trim indicator (follows input)
    - 2EA0: Elevator trim deflection, in radians, as a double (FLOAT64). Up positive, down negative.
    - 3338: Elevator Trim Axis input value, post calibration, just before being applied to the simulation (if allowed to by the byte at offset 310A).

And if its a PFC trim wheel and you are using the provided PFC driver, then also see offset 3370/3BA8

John

 

 

[dmahr]

Hi John,

many thanks for your fast response. 

I investigated this offset with the "Monitor FSUIPC Data" program from Ruscool already: it gave just zeroes. This evening I wrote my own program and - voila - there were data. I will try to use this offset for my purpose. I can disengage trim inputs as long as the autopilot is on and just follow these data with my wheel (it is selfmade).

Thanks again

Detlef

[Pete Dowson]

4 minutes ago, dmahr said:

I investigated this offset with the "Monitor FSUIPC Data" program from Ruscool already: it gave just zeroes.

I don't know that program, but the official ways to monitor offsets are:

1. Use the built-in Logging, via the Monitor facility on the right hand side of that options tab.

2. Use the utulity FSInterrogate2, which although a little more complicated to use is very feature-rich.

Pete

[John Dowson]

FYI, FSInterrogate2 is included in the SDK for FSUIPC, and I think is also now one of the 'extras' for installation in FSUIPC6, outside of the SDK.

 

[dmahr]

Thanks again,

the 0BC0 offset works fine. My wheel is spinning now.

FSInterrogate2 did not work. It reports an "access violation ..." report and I gave up.

Detlef

[Pete Dowson]

5 hours ago, dmahr said:

Thanks again,

the 0BC0 offset works fine. My wheel is spinning now.

FSInterrogate2 did not work. It reports an "access violation ..." report and I gave up.

FSInterrogate has always worked fine. Maybe more details would help the author who donated it long ago, but he's probably long forgotten it.

I use it a lot. it is very useful indeed.

Pete

 

[rotemcohen]

Hey guys, I'm sorry but I don't know what "offset" means. I'm trying to get the trim wheel to do something becasue it currently does very little. What do I do? Thanks.

[Pete Dowson]

1 hour ago, rotemcohen said:

I'm sorry but I don't know what "offset" means.

It's just a reference or address to a piece of data provided by FSUIPC.

1 hour ago, rotemcohen said:

I'm trying to get the trim wheel to do something becasue it currently does very little.

Is it motorized? If so surely it must come with a driver and instructions? If not then it won't turn under PC control, it is just a manual trim.

Pete