ASTRO-PHYSICS GTO KEYPAD Addendum - Pagina 5
Blader online of download pdf Addendum voor {categorie_naam} ASTRO-PHYSICS GTO KEYPAD. ASTRO-PHYSICS GTO KEYPAD 10 pagina's. Plus supplemental information for customers outside of north america and the revised gto quick star drift method of polar alignment
Pagina afdrukkenHorizon Check in the Servo
Command:
Response:
A●bug●was●found●in●the●servo's●internal●horizon●check●in●the●E1●and●KE1●microcontroller●chips●for●the●GTOCP1●and●
GTOCP2●control●boxes.●●The●bug●existed●in●all●prior●versions●of●the●chip.●●Later●versions,●beginning●with●F●and●going●
through●R●partially●addressed●the●issue,●but●it●will●be●version●S●(in●beta●testing●as●of●1-14-10)●that●will●fully●solve●the●
problem.
Since●most●planetarium●software●and●the●Astro-Physics●keypad●firmware●all●perform●their●own●horizon●check●calculations,●
this●command●is●rarely●activated.●●The●horizon●check●was●included●in●the●command●set●for●people●who●may●be●writing●their●
own●control●software.●●
At●this●point,●we●recommend●that●NO ONE SHOULD USE THE HORIZON CHECK in●the●servo.●
Variable Tracking
The●following●text●replaces●the●text●for●these●commands●on●page●87●of●the●v.4.12●keypad●manual●dated●March●7,●
2008●(Appendix●B).●●It●applies●to●GTO●servo●microcontroller●chips●version●G●through●R.●●In●addition●to●a●more●thorough●
explanation,●please take special note of the difference between the northern and southern hemispheres for these
commands.●●●●●Also●note●that●the●command●operates●the●same●in●both●hemispheres●starting●with●version●S.
Command:
Response:
This●command●sets●the●tracking●rate●in●the●RA●axis●("RR")●or●DEC●axis●("RD")●to●sxx.xxxx.●●The●rate●is●expressed●in●terms●
of●multiples●of●the●sidereal●rate●and●can●be●positive●or●negative.●●●●Note●that●earlier●published●text●on●this●command●had●
three●digits●to●the●left●of●the●decimal.●●●This●was●incorrect.●●●Only●two●digits●(not●counting●the●sign)●are●allowed●to●the●left●of●
the●decimal●point.●●●●You●can●use●up●to●four●digits●to●the●right●of●the●decimal.●●●The●format●above●is●correct.
For●the●Right●Ascension,●the●rate●is●added●to●or●subtracted●from●the●default●sidereal●rate●of●1.0000x.●●●If●you●had●the●mount●
set●to●a●different●rate,●like●lunar,●this●is●irrelevant●to●the●command.●●●It●will●always●be●implemented●in●terms●of●the●sidereal●
rate.●●●
This●command●operates●differently●depending●on●the●hemisphere●you●are●in.●●●
● ●
In●the●northern●hemisphere,●the●rate●is●added●to●the●sidereal●rate.●●●For●example,●●●●:RR●+0.1#●●●would●result●in●the●
mount●tracking●10%●faster●than●sidereal●(●1.0●+●0.1●=●1.1●).●●●●:RR●-1#●●●would●stop●tracking●(●1.0●+●(-1.0)●=●0●).
● ●
In●the●southern●hemisphere,●the●rate●is●subtracted●from●the●sidereal.●●●●●Using●the●same●examples●above,●●●●:RR●+0.1#●●
would●result●in●the●mount●tracking●10%●slower●than●sidereal●(●1.0●–●0.1●=●0.9●).●●●●●:RR●-1#●●●●would●result●in●the●mount●
tracking●at●twice●the●sidereal●rate●(●1.0●–●(-1.0)●=●2.0●).
● ●
Starting●with●version●S,●the●command●operates●the●same●in●both●hemispheres●and●follows●the●convention●used●for●the●
northern●hemisphere●above.●●●Also●note●that●Rev,●S●and●later●add●another●digit●to●the●right●of●the●decimal●to●increase●
the●fine●resolution●of●the●command.●●●The●command●is●therefore:●●●●●●●:RR●sxx.xxxxx#
The●variable●Dec.●rate●works●from●a●mechanical●perspective.●●●With●regard●to●the●commands●in●the●servo,●●:RD●+xx.xxxx#●●
will●cause●clockwise●rotation●of●the●Dec.●axis●when●viewed●from●above;●●●:RD●–xx.xxxx#●●will●cause●counter-clockwise●
rotation.●●●●The●pier●side●makes●no●difference,●nor●does●the●hemisphere.●●●●●It●is●better●to●think●in●terms●of●the●mechanical●
rotation●of●the●axis●because●it●is●consistent.●●●●Remember●that●in●the●northern●hemisphere,●on●the●west●side,●clockwise●is●
south;●●on●the●east●side●clockwise●is●north●and●just●the●opposite●holds●true●in●the●southern●hemisphere.●
As●with●the●Right●Ascension,●versions●S●and●later●add●another●digit●to●the●right●of●the●decimal●in●declination.
:ho#
:hq#
(none)
:RR sxx.xxxx#
:RD sxx.xxxx#
"1"
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