PEC Option, Telescope Motion | iOptron 7201, 7200 guide

5.6. PEC Option

This function only works for a non-high precision encoder version of CEM60 mount.

5.6.1. PEC Playback

You can turn “PEC Playback On” while you do the tracking, especially for long time astro- photography. 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 can 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 needs to record the PE first. The periodic error of the worm gear drive will be used to correct periodic error. The data will be lost when the power is turned off.

Here’s how to use the PEC function.

1.Setup the mount with a telescope in autoguiding condition by connecting a guiding camera to a computer via mount’s Guide Port or ASCOM protocol;

2.Select “MENU=>Settings => Set Guiding Rates.” Set a guiding speed from 0.10X to 0.80X. The default number is 0.25X;

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 record the PE.

4.It takes the worm gear 300 seconds to make one complete revolution. After 300 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.

5.7.Telescope Motion

5.7.1. Park Scope

This function parks the scope to a preset position.

5.7.2. Search Zero Pos.

In the event of power failure, the mount will lose all its alignment info. It will be very troublesome for a remote observation site where the mount might be controlled via internet. The CEM60 has been equipped with a function that can find the zero position for an initial mount set up.

Select “Search Zero Pos.,” the mount will starting slew slowly and find the R.A. and DEC position to set the mount to zero position. Do a “One Star Align” to correct any zero position discrepancy.

NOTE: This function is not intended for daily zero position setup.