5.4.11. Set RA Guiding
The function is for the EC version of the GEM45 only. You can turn off R.A. guiding by selecting
“
Inhibit
R.A. Guiding
” to allow the high precision encoder to correct the tracking error, or turn the R.A. guiding on
by selecting
“
Allow
RA Guiding
” to allow the mount to receive guiding corrections from the guiding
software.
The power on default setting is “
Allow RA Guiding
”.
5.4.12. Language
Select one of supported menu languages. Currently it has English and Chinese.
5.5. Electric Focuser
This function controls an iOptron electric focuser.
5.6. PEC Option
This function only works for a non-EC GEM45 mount.
5.6.1. PEC Playback
You can turn “
PEC Playback On
” to improve tracking accuracy which is especially useful for long exposure
astrophotography. The default status is
“
PEC Playback Off
” when the mount is turned on.
5.6.2. Record PEC
All equatorial mounts have a small variation in the worm gears which may be corrected by using Period
Error Correction or PEC. PEC is a system which improves the tracking accuracy of the mount by
compensating for variations in the worm gear and is especially useful when doing astrophotography without
autoguiding. Because the variations are regular, it is possible to record the corrections required to cancel
out the worm gear variations and to play them back to correct the periodic error caused by the variations.
In order to use the PEC function, the Go2Nova
®
hand controller first needs to record the periodic error. The
periodic error of the worm gear drive will be used to correct periodic error.
To use the PEC function:
1. Setup the mount with a telescope in autoguiding configuration by connecting a guiding camera via
the mount
’s Guide Port or using the ASCOM protocol;
2. Select
“
MENU
=>
Settings
=>
Set Guiding Rates
”. Set a guiding speed from 0.10X to 0.90X. The
default setting is 0.50X;
3. Then press the
BACK
button and select “
PEC Option
”
from the menu. Use the
▲ and ▼ scroll
buttons to display the “
Record PEC
”
option and press
ENTER
to start recording the periodic error.
4. It takes the worm gear 400 seconds to make one complete revolution. After 400 seconds PEC will
automatically stop recording. The PEC value will be permanently stored inside PEC chip on R.A. motor
drive until a new data are recorded.
5. If you want to re-
record the periodic error, select “
Record PEC
” and repeat the recording
processes again. The previously recorded information will be replaced with the current information.
5.6.3. PEC Data Integrity
This function will check the recorded PEC data integrity.
