Trouble shooting
Well I hope this page isn’t needed very much, but I’ll try
to cover the “Hot” topics J Feel free to email me (jlerch@tampabay.rr.com) if I haven’t
covered your questions!
Video Stuff
If the Main display screen looks like this:

Then Rtaft isn’t getting any video input.
Try the following to see if you can get video running:
1.
Goto “Video Control / Select” and make sure your video capture
system is selected
2.
Goto “Video Control / Format” and try selecting different
video acquisition modes:
a.
Usually RGB555, RGB16, I450, or something along those lines
b.
Also make sure your at 320&240 Pixels
3.
If that doesn’t work, try playing with the source and Display
options tabs as well.
4.
If all that fails,
a.
Shut down RTAFT,
b.
Goto the Rtaft program folder (Usually C:\program files\rtaft)
c.
Look for the executable called Vbmemcap.exe
d.
Try running this bit of code from the original creator of my
Video Capture software.
e.
If you still don’t get any video, try running whatever video
capture software came with your hardware
f.
If it still doesn’t work, well I don’t know what to say J,
try contacting your video hardware manufacturer!
Next, If you can get video, but the mirror will not fully
illuminate
- Make
sure your near ROC
- If the
outer edges won’t illuminate
- Try
a wider slit source (or a slitless source!)
- Get the
camera lens as close as possible to the knife edge! (I actually had to
file away some plastic to test an F/3.8 mirror once!)
Motor stuff
- Make
sure your parallel port is on LPT1 with an address of &H378
- If
nothing happens, shut down RTAFT, and try it again using Mel’s Scope.exe
code
- If the
motors don’t move in the right direction, check the options in Platform Settings
2nd tab
- IF
your getting inconsistent readings
- Make
sure the motors aren’t binding or skipping steps
- See how
much back lash you have, and try to eliminate it!
- Increase
the frame average sliders in the Advanced options tab.
- Make
sure the step size you entered is the “REAL” step size J
i.
Try hooking up a micrometer to double check amount of travel
ii.
Double check for binding / Stalling
AutoTest Failures
- If
starting an auto test causes the system to get entirely lost, check the
following:
- Knife
edge side is correctly selected
- Motors
move in the anticipated direction (LEFT and RIGHT is from the point of
view of standing behind the test platform with the platform between you
and the mirror down range!
- Fully
illuminate the mirror prior to starting a test (its possible to half
illuminate the mirror by being on the wrong side of the knife edge!)
- OH
YEA, make sure that your light source is actually on the SHARP side of
the knife edge J Its possible for the light source to
enter the camera on the DULL side of the knife, and still make pretty
Foucault images, but the code will get really confused!
- Auto
Test just hunts Left/Right while trying to set the “Shades of Gray” value
- Make
sure your light source is bright enough (>200 pixel count with fully
illuminated mirror!)
- Increase
Frame average in the Auto-Test variables / Knife IN/Out stuff tab!
- Make
sure the Min / Max “shades of Gray” value has enough “dead space” IE at
least a difference of 30
- Make
sure the Min / Max “shades of Gray” value is reasonable. Centered somewhere between 30 and 90
pixel counts! (higher can cause problems!)
- Watch
out for Air Currents, an insulated test tube is helpful here! (Our is made
from fiberglass A/C duct boarding!)
- Make
sure the mirror and platform are on sturdy ground!
I’ll add additional troubleshooting
points as reports come in from the field J
Take Care,
James
jlerch@tampabay.rr.com