BFF Motion Driver v2 - Short User Guide


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3. Operation

To run the software double click on the motion driver .exe in your installation directory or on a shortcut setup to point at the .exe.

The driver window has a number of buttons - each has a pop-up tool tip which provide more details of the button function. The buttons are -


Start - The motion driver reads its run settings from a .bff configuration file, the Start button will open a file selection window and then proceed execution of the driver operation with the settings from the selected config file. See the settings section for details of the .bff configuration file parameters.

A number of default .bff config files are included in the download zip package. Use the one for your platform type as a start for your set up. See the settings section for information on settings adjustments that will need to be made.

Stop - stop and close the driver (or hit programmed STOP hot key).

Re-Set - re-start with the current configuration file.

Re-Load - re-load a new configuration file.

Info – toggle the full driver window with information.

Capture - capture the maximum and minimum flight accelerations and pitch and roll angles.

The Flight Data Limits Capture window allows you to capture the recent maximum and minimum values of key flight parameters. These include forward, lateral and vertical accelerations and pitch and roll angles and good knowledge of these is needed to set the configuration settings for the driver. Use the capture button to capture the accelerations associated with key flight events such as takeoff accelerations, braking decelerations, vertical lift-off accelerations, turbulence induced accelerations etc etc. With this information you will be able to better judge the acceleration cap levels and scaling to the platform movement range. NOTE that the acceleration values shown are factored by the scaling parameters specified in the .bff configuration file.

Scope – activate the built-in virtual oscilloscope to display real-time traces of the motion cues. The traces are of the motion cues by DOF before any mixing or management processing is done by the driver unless the Scope_Mode=1  parameter is set in the .bff config file when the outputs are then by actuator. The output will be active so long as the flight sim is not paused, this will allow the active motion cues to be displayed even with the driver on Hold.

The oscilloscope can be used with the in-program cue setting windows (see below) to assess adjustments to the motion cue settings whilst the driver is running and so allow the effects of changes to be assessed rapidly. IT IS RECOMMENDED THAT THIS IS DONE WITH THE PLATFORM DRIVE INACTIVE!

The virtual oscilloscope is implemented using Michael Bernstein's excellent Software Oscilloscope DLL – see his web site at for more details. The traces can be manipulated on the scope using the buttons provided as is normal for any oscilloscope.


Drive - engage active platform drive. The motion cue output will ramp from the current parked/start position to the current live position from the flight sim.

Hold_Start_Position - return the platform to its start/parked position. In this mode a constant stream of position demands are output set to the hold position of the platform actuators.

Start_PID_Controller - start the BFF PID Servo Controller application – this will require the data output mode to have been set to MEM, otherwise the Servo Controller will not start. For more details see the PID Servo Controller section.

Manual Override - manually override the position demand outputs from the driver.

This will open the Override window which has three sliders – one for each output channel/DOF of the driver. Moving a slider will adjust the value of the position demand output for that Actuator or DOF within the full 0-255 range if the “Enable” check box has been checked for the Actuator. If the “Follow Act 1” box is checked than all three sliders will follow the position of the Actuator 1 slider.

If the “By DOF” checkbox is checked on the main UI the output will be by DOF and not by individual actuator. For coupled drive platforms this will result in all the actuators moving as required for the selected DOF.

WARNING – Because this feature is intended as an aid to establishing the working range of a platform the sliders operate within the FULL 0-255 position output range. Use with great care – if your platform drive is active the platform may move suddenly in response to movements of the sliders, if you demand a position out-with the physical working range of your platform the platform will drive onto its end stops. Trial this function with the platform drive INACTIVE to get a feel for its operation.

The sliders can be moved with the mouse or more sensitively with the left/right keyboard arrows.


In-Program Cue Adjustment Settings – there are four small buttons provided - P, R, H and M to open the settings windows for the Pitch, Roll and Heave degrees of freedom and the actuator mix proportions for Mode=2 set ups. For details of the individual settings see the pop-up tool tips.

Opening either of the three settings windows will send the driver output back to the “hold” position to disable live output of the cues whilst the settings are being adjusted.

To adjust a setting make the change in the appropriate text box and click Use. This will make the adjusted settings active in the driver but will not save them to file.

To save the new settings to the active configuration file click Save.

On the Pitch and Roll windows a simple settings wizard is included. This allows easy setup of the main cue range and scaling parameters (not the noise and washout filter time constants) to match the cue output to specified g-force and/or aircraft orientation ranges - follow the instructions in the pop-up tool-tips.

IMPORTANT – Take great care when making changes to the cue settings as they can directly impact on the motion range. It is recommended that the adjusted cue output is viewed in the Virtual Oscilloscope and its stability assessed BEFORE the driver is put back in Drive mode and the platform made active.



Drive, Hold and Stop HotKeys and/or joystick hot-buttons can be programmed using the settings in the .bff configuration file. See the settings section.

\+B (Backslash plus B) – will toggle the pre-recorded light turbulence heave motion on or off – the MSFS driver starts with this ON. The effect can be scaled or disabled completely by adjusting the value of the Turb_Scalea parameter in your .bff configuration file (set =0 to disable).

\+R (Backslash plus R) – will initiate a new heave motion recording run. This will last two minutes and will end by closing the driver and writing the newly recorded data to the BFF-Turb.txt file in the driver's working directory. This will overwrite the existing file, so back it up if you want to keep the original data supplied in the driver zip package. To use this facility set up a flight in your aircraft of choice and fly straight and level – best to use the auto-pilot. Set the weather conditions to remove all weather effects except an additional turbulence level – you chose what level of turbulence in the User Defined Weather settings. The aim is to get a 2 minute run with turbulence induced heave movement alone which can later be superimposed on the live heave motion cue.

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