Reset All Settings; Language; Electric Focuser; Pec Option - iOptron CEM70 Instruction Manual

5.4.14. Reset All Settings

Reset all the settings to factory default.

5.4.15. 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 standard CEM70 and CEM70G 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
error. The periodic error of the worm gear drive will be used to correct periodic error.
We recommend using a guiding camera to record the PE with autoguiding. Here's how 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 348 seconds to make one complete revolution. After 348 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.
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hand controller first needs to record the periodic
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