Eagle Tree OSD Pro - Manual (Page 16)

Copyright © 2009-2012 Eagle Tree Systems, LLC
http://www.eagletreesystems.com
Page 16
The OSD Pro constantly monitors your receiver to determine if the selected Safety Mode should be invoked. The things that trigger Safety Mode vary
between receiver types.
For receivers which do not hold the servos at the last position or failsafe position when signal is lost (the servos either go limp or move randomly when the
Transmitter is turned off), the OSD Pro looks for bad pulses (pulses of the wrong duration), or the absence of pulses. If enough bad or missing pulses are
evident in a short period, Safety Mode is invoked, until the error rate decreases to a good level.
Setting up and Testing RTH
The following sections describe how to set up RTH with your particular radio gear and model type. Note that, regardless of the type of gear you have, it is
likely others have already set up RTH with the exact same equipment. Many OSD Pro users have described their RTH setup on this thread:
http://www.rcgroups.com/forums/showthread.php?t=924018
If anything is confusing or not working as you would expect, this thread is a good place to start for help.
Setting up RTH with Receivers that Support a Throttle Failsafe (Recommended for Electric Models)
For receivers that let you program a throttle failsafe (nearly all modern receivers) the most straightforward way to set up RTH is as follows:
a)
Program your radio’s throttle failsafe as described in the paragraph below.
b) Set the “Choose Model Wing Type” to either “Standard” or “Elevon” in the Configure Radio Control menu.
c) Set the “Choose Receiver Type” to “PCM/FS” in the same menu
d) Set “Number Failsafe Chans on RX” to “1 FS Chns” in the same menu.
e) Set the “Select Desired Safety Mode” menu item in the Safety Mode menu to “Rtrn Home”
f) Read the additional information below, and then follow the remaining steps in the “RTH Testing/Adjustment Procedures” section below.
When using the settings above, RTH will be invoked whenever your throttle is detected by the OSD Pro to be in the failsafe position for more than a second
or two.
To prevent RTH from activating erroneously during normal flight, make sure your receiver’s throttle failsafe is programmed so that the failsafe position is
not encountered in normal flight. One way to do this is to temporarily set your receiver’s throttle channel for “extended servo travel” or (preferably) use
your throttle trim to move the throttle farther to the off position than normal, and then program your throttle failsafe to that position. Then, return your
receiver to normal throttle servo travel (or trim the throttle off position up), after programming the throttle failsafe to the extreme off position. Now, the
failsafe position of the throttle will still turn the motor off, but the failsafe position cannot be reached if you move your throttle stick to the off position during
normal flight, unless you trim down on the throttle trim. Note: for non-electric models, this method would not be a good idea, since the off failsafe position
of your throttle will shut the engine off, which will make RTH much less useful.
An added benefit of using the throttle trim to set the failsafe position is that you can test RTH in-flight by trimming the throttle to extreme off position using
your throttle trim button. Since this will put the throttle in the failsafe position previously programmed, RTH will activate. Then, RTH can be deactivated
simply by trimming your throttle up again.
Note: The failsafe positions used by your receiver are detected during the Servo Analysis Wizard, so you will need to program your receiver’s throttle
failsafe position before running the Servo Analysis Wizard. You must rerun the Servo Analysis Wizard after any reprogramming of your radio’s failsafe
positions!
Setting up RTH with Receivers that Support Three or More Failsafe Channels
In most cases, using the “Setting up RTH with Receivers that Support a Throttle Failsafe” method described above is the best choice for receivers that
support failsafes. However, for receivers with 3+ failsafes, Safety Mode is invoked whenever all three receiver channels (throttle, aileron/rudder, elevator)
reach the failsafe position for more than a brief period, when you set the Set “Number Failsafe Chans on RX” to “3+ FS Chns” in the Configure Radio
Control menu.
Note: The failsafe positions used by your receiver are detected during the Servo Analysis Wizard, so you will need to program your receiver’s throttle
failsafe position before running the Servo Analysis Wizard. You must rerun the Servo Analysis Wizard after any reprogramming of your radio’s failsafe
positions!
Setting up RTH with “PPM” Receivers that Don’t Control the Servos When Radio Reception is Lost
If your receiver stops controlling the servos if you turn off your radio (the servos no longer are held in one position, and/or start moving randomly), you will
need to configure RTH as follows:
a)
Set the “Choose Model Control Type” to either “Standard” or “Elevon” in the Configure Radio Control menu.
b) Set the “Choose Receiver Type” to “PPM/ No FS” in the same menu. Note: Since “PCM” receivers should never have bad or missing pulses, RTH will
never activate if “PPM/ No FS” mode is selected with a PCM receiver!
c) Set “Number Failsafe Chans on RX” to “No FS Chs” in the same menu
d) Set the “Select Desired Safety Mode” menu item in the Safety Mode menu to “Rtrn Home”
e) Read the additional information below, and then follow the remaining steps in the “RTH Testing/Adjustment Procedures” section below
When set up in this mode, the OSD Pro looks for bad pulses (pulses of the wrong duration), or the absence of pulses. If enough bad or missing pulses are
evident in a short period, Safety Mode is invoked, until the error rate decreases to a good level.
Setting up RTH with Models with Receivers that maintain the last Servo Position, but Don’t Support Programmable Failsafes