Eagle Tree OSD Pro - Manual (Page 17)

Copyright © 2009-2012 Eagle Tree Systems, LLC
http://www.eagletreesystems.com
Page 17
Figure 11
For receivers which do maintain the last position of the servos when signal is lost, but with no failsafe positions programmed, Safety Mode is activated when
no servos move for a few seconds. This setup is not ideal, since Safety Mode will turn on if you don’t move your transmitter sticks for a few seconds,
even if your radio link is good!
For this type of radio, you would choose the following settings:
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 “PCM/FS” in the same menu.
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
Setting up RTH with Models that have more than Three Flight Controls, and the Receiver does not support Failsafes
If your receiver does not support failsafes, and your model has four or more flight controls (for example, Aileron, Elevator, Rudder, Throttle), additional
steps may be needed to use the the Safety Mode features. Since the OSD Pro will take control of only three of the control surfaces, the fourth control will
be left connected directly to your receiver. If the receiver loses signal, and does not support failsafe, the fourth control could move randomly or remain in its
last position. For example, if your plane has rudder, aileron, elevator and throttle, and you connect rudder, elevator and throttle to the OSD Pro, the aileron
channel, which is connected directly to the receiver, could move randomly if the receiver loses signal and doesn’t support failsafe. A possible solution to
this problem is to purchase a “servo fail safe unit” which is connected between the fourth receiver channel, and the fourth servo, which will provide failsafe
operation if the receiver loses signal. Or, consider upgrading to a failsafe capable radio.
Using the Return to Home with Stabilization Systems
RTH works best when used with the Eagle Tree Guardian Stabilization Expander.
RTH can also be improved significantly if a 3
rd party stabilization system, such as the FMA TM Co-pilot TM , is utilized. The stabilization system’s servo inputs
would normally be connected to the servo outputs of the OSD Pro. Then, the servos themselves are directly connected to the stabilization system’s output.
Special information about the FMA
TM Co-pilot TM CPD4 TM
If you are using the FMA TM Co-pilot TM CPD4 TM , there are two problems you may encounter. The first problem is that the CPD4 TM computer apparently
cannot handle receiving two or more servo pulses simultaneously. Futaba TM PCM receivers send simultaneous servo pulses, and FMA TM requires that you
use a “servo buffer” (which they sell) to slightly delay one of the incoming pulses.
The OSD Pro sends the servo pulses simultaneously by default (just as Futaba
TM PCM receivers do), which might confuse the Copilot unless the “servo
buffer” hardware is installed on one of the servo connections. If you set the FMA co-pilot w/o servo buffer parameter in the Artificial Horizon
Configuration menu to “Yes”, it causes the OSD Pro to skew the servo pulses in RTH mode. Unfortunately, this causes the voice announcements to
automatically be turned off during RTH mode (including the “signal lost!” announcement that would normally occur when RTH mode is invoked). That’s
the only drawback of setting this option to “Yes.” Note that it is believed that the latest FMA
TM Co-pilot II TM product does not have this shortcoming.
Secondly, another potential problem can occur with the CPD-4 Co-pilot
TM , if you use a spare receiver channel to control its gain. If you use a spare servo
channel to remotely set the gain, and your receiver loses the signal, one of three things might happen:
a) If your radio doesn’t send any pulses at all when it loses receiver signal, what happens with the Co-pilot TM is unknown. This is true with or
without the OSD Pro connected.
b) If your radio is PCM and has failsafes, but you have not set the failsafe of the spare channel to something reasonable for the Co-pilot TM (or if there
is no failsafe setting available on that channel), stabilization will again be in an unknown state. Again, this is true with or without the OSD Pro
connected.
c) Even if you have set the failsafe for the spare channel to a reasonable value for the Co-pilot TM , a problem can still occur, since the pulses from the
receiver to the copilot are not synchronized with the pulses from the OSD Pro to the Co-pilot TM , during RTH mode. The copilot can occasionally
glitch (moving the servos wildly) whenever the servo gain pulse momentarily overlaps with one of the RTH pulses. Again, this is due to the
perceived shortcoming of the CPD4
TM in receiving two or more servo pulses simultaneously. If, during testing of RTH mode, you observe servo
excursions a few seconds apart, use the manual gain setting for your Co-pilot TM .
Running the Servo Analysis Wizard
Part of setting up RTH is running the Servo Analysis Wizard. This wizard can be run either on your PC or laptop with the Windows software, or from the
stick menus. Generally, the Windows software version is quicker and easier, but the stick menu method can be used at the field, without a computer. They
both work approximately the same way.
During the wizard, you will be asked to move your radio sticks, and turn your transmitter on and off. Before running the wizard, ensure your model’s
motor is disconnected or otherwise disabled. WARNING: only run the Servo Analysis Wizard when your model is on the ground! NOTE: loading a
previously saved configuration file will overwrite wizard settings with their previous state.
Running the Servo Analysis Wizard from the Windows Software
To run the Windows software version of the Wizard, with your OSD Pro
connected to USB, first click “Hardware, Choose Parameters to Display on
Video OSD” to invoke the OSD Pro setup page. Then, click the button in
the lower right-hand corner labeled “Run Servo Analysis Wizard.” Then,
the wizard page shown in figure 11 should appear.