Nexstar SynScan instruction manual Linking with a Computer, T o Guiding, Periodic Error Correction

Page 11

Linking with A Computer

Another feature of SynScanTMis the ability to connect to a computer via a serial communication cable. Many commercially available planetarium softwares can be used to control SynScanTM. SynScanT"Version 3.00 and later is compatible with Celestron 5i/8i and NexStar GPS command protocol.

1.

Make sure that the telescope has been aligned.

 

Hand Control

2.

Connect the RS-232 cable to the RJ-11 connector on the

C b 5 3

hand control and to the COM-port of your computer (Fig.p)

-

 

Do not use RS-232 cable other than the one provided to connect between the hand control and your computer. It may damage your computer or the hand control. If you are making your own cable based on the information provided in Appendix B, make sure that only pin 2, 3 and 5 connect to the com connectoron your computer.

3.In the planetarium software of your choice, choose "Celestron NexStar 5i" or "Celestron 8/9/11 GPS" in the driver setup menu and follow the instructions provided by your program to establish the connection to the telescope. The SynScan'" should be under the full control of your computer once the connection is successfully established.

4.When you are finished, follow the instructions provided by your software to close the connection to the telescope.

RJ- 11

aRJ-11 Pin-outs

I = EXPD+ 2= -rD

3= GND 4= EXPD- 5= RD

6 5 4 3 2 1 6= +12v

See Appendix B for

more information on

RS-232 connection.

A u t o Guiding

The SynScanrMhas a designated autoguider interface on the mount for use with

an auto guider (see Fig.a, a-I). The pin-outs on the 6 pin modular connector is

 

I = NC

 

2= Ground

ST-4 compatible and can be used for most autoguiders on the market. Refer to

 

 

3= +RA (left)

Fig.q when connectirlg the autoguider cable to the SynScanTM and calibrating the

 

4= +DEC (up)

autoguider. Relay box can be added for extra protection. Note that the four inputs

654321

5= -DEC (down)

are active-low, with internal pull-ups. Guiding speed can be adjusted using the

6= -RA (right)

 

 

Auto Guide Speed function in the Setup Menu.

Periodic Error Correction

Periodic Errors are found in almost all worm gears due to slight eccentricities and misalignments. The PEC (Periodic Error Correction) function provides a manual correcting method to reduce the amplitude of the worm errors. By recording a full cycle of guiding actions versus motor shaft angle, SynScanTMcan work to compensate for the drifting in the RA sidereal tracking caused by the periodic errors. Below describes a step-by-step procedure on how to perform the PEC:

PEC Training function is recommended for advanced users interested in long-exposure astrophotograhy only. Careful guiding is required. Regular sidereal tracking is adequate for all casual visual use of the SynScan" and PEC Training is not required.

Required acccssory: Illuminated reticle eycpiccc with double crossline pattern capable of producing at least 300X magnification in combination with your telescope. The true field of view should not exceed 10 arc min. See "Choosing the appropriate eyepiece" in the HEQ5lEQ6 manual for more information on calculating the field of view.

Image 11
Contents Page Page SynScanTM Hand Control Powering the SynScanTM1ntroduction to the SynScanTM Dual Purpose keys Mode keysDirectional keys Scoll Keys Fig.eAID Tial SetupTwo-Star Alignment Star ~ l i ~ n r n e n tThree-Star Alignment Pointing Accuracy Enhancement PAE One-Star AlignmentSelecting an Object 0bject database in the SynScanTMSaving an object to the database Utility FunctionsRecalling an user defined object Identifying an Unknown ObjectT o Guiding Periodic Error CorrectionLinking with a Computer Page \ mm@1 SynScan F~rmwareLoader Main Menu SynScanTwSPECIFICATIONS Movement Eyepiece view Page Page Hand Control Description PC Command Ascii Response Sending a track rate through RS232 to the hand control Additional RS232 Commands

SynScan specifications

The Nexstar SynScan is a highly regarded mount and telescope system, catering to both amateur astronomers and seasoned professionals alike. Renowned for its ease of use, portability, and advanced technology, it significantly enhances the stargazing experience.

One of the standout features of the Nexstar SynScan is its computerized GoTo mount. This system allows users to easily locate and track celestial objects. With an extensive database of over 40,000 celestial bodies, including stars, planets, nebulae, and galaxies, the SynScan offers an intuitive way to explore the night sky. The built-in database also includes user-defined objects, making it versatile for personalized astronomical pursuits.

The SynScan's Dual-Axis Tracking mechanism is another major advantage. It accurately tracks celestial objects as they move across the sky due to the Earth's rotation, ensuring that users can view objects for extended periods without needing to manually adjust the telescope. This functionality is particularly beneficial for astrophotography, as it reduces image blurring caused by slight movements.

In terms of technology, the Nexstar SynScan utilizes a precision motor drive and encoders to enhance tracking accuracy. The mount features AC servo motors, which provide smooth and silent operation. The included hand control is user-friendly, with a backlit screen that allows for night-time navigation without disturbing your surroundings.

The system's ease of setup and portability are important characteristics, particularly for users who wish to observe in remote locations. The Nexstar mount is lightweight and compact, making it easy to transport and assemble. Users can quickly set up the telescope in a matter of minutes, an advantage for spontaneous night-sky explorers.

Additionally, the SynScan offers various power options, including the ability to use AA batteries or an external power supply. This flexibility ensures that users can operate their telescope in different environments without worrying about finding power sources.

Lastly, the Nexstar SynScan is compatible with popular astronomy software, enabling users to enhance their observing sessions with additional features such as software-guided observations and advanced tracking capabilities. This integration with technology allows for a rich observing experience where the vastness of the universe is made more accessible.

In conclusion, the Nexstar SynScan stands out for its combination of advanced technology, user-friendliness, and portability, making it a top choice for anyone looking to delve deeper into the wonders of astronomy.