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キーパッド ASTRO-PHYSICS GTO KEYPADのPDF 補遺をオンラインで閲覧またはダウンロードできます。ASTRO-PHYSICS GTO KEYPAD 10 ページ。 Plus supplemental information for customers outside of north america and the revised gto quick star drift method of polar alignment

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the●keypad●won't●let●you.)●●●To●correctly●calculate●the●sidereal●time,●both●the●keypad●and●the●mount●must●know●whether●you●

are●east●or●west●of●the●Prime●Meridian.●●●●The●error●you●would●introduce●by●trying●to●"trick"●the●mount●is●considerably●larger●

than●the●30●arc●second●maximum●error●in●longitude●that●you●would●have●by●rounding●to●the●nearest●minute.●●●External●

software●like●PulseGuide●can●initialize●the●mount●with●the●full●eastern●longitude●including●seconds.

Western Longitudes with Eastern Time Zones

(see pp. 14-16)●●●There●is●currently●no●provision●in●the●keypad●for●dealing●with●the●situation●in●far●western●Europe●and●parts●

of●Africa●(i.e.●western●France,●western●Algeria●and●most●of●Spain)●where●the●longitude●is●a●west●value,●but●the●local●time●is●

on●the●CET●standard●of●one●hour●east●(local●CET●=●GMT●+●1)●or●two●hours●east●in●the●summer●(CEST●=●GMT●+●2).●●●There●

are●no●cases●of●locales●in●eastern●longitudes●that●are●on●western●time●zones●that●we●are●aware●of.●●●

The●keypad●uses●four●pieces●of●information●to●calculate●the●correct●GMT●(and●thus●the●correct●LST●and●horizon●

coordinates).●●●To●calculate●GMT,●it●needs:●1●–●local●time;●●2●–●time●zone;●●3●–●daylight●savings●factor;●●and●4●–●whether●the●

longitude●is●east●or●west.●●●Version●4.20●will●address●the●situation●of●western●longitudes●with●eastern●time●zones,●probably●

with●a●separate●E●or●W●setting●for●the●time●zone●that●is●not●tied●to●the●longitude,●but●the●current●firmware●does●not.

For●people●in●this●situation,●probably●the●easiest●solution●is●to●keep●the●keypad●entirely●set●to●GMT.●●●

1.● Set●the●local●time●to●GMT.

2.● Set●the●time●zone●for●ALL●entered●locations●to●00.

3.● Leave●the●Daylight●Savings●set●to●0●=●Winter●all●the●time

4.● Enter●your●longitude●for●all●locations●correctly●using●E●or●W●as●appropriate.

5.● Remember●that●in●use,●your●keypad●will●no●longer●display●the●local●time.●●●If●you●wish●to●know●"what●time●it●is,"●you●will●

need●to●either●look●at●your●watch●or●convert●GMT●to●local.

Please note:●●This●is●a●more●serious●issue●than●many●of●those●that●follow.●●●This●affects●how●the●servo●is●initialized,●and●

therefore●affects●proper●operation●of●the●mount●from●the●very●beginning.●●It●is●important●if●you●are●in●a●western●longitude●

with●an●eastern●time●zone●that●you●make●the●adjustments●outlined●above●to●ensure●correct●and●safe●operation.●●●Both●the●

servo●and●the●keypad●use●the●"equations●of●time"●to●calculate●the●meridian●and●the●horizons.●●●The●equations●of●time●start●

from●GMT,●and●then●incorporate●your●longitude.●●●●The●important●thing●to●remember●is●that●both●the●keypad●and●the●servo●

must●be●able●to●determine●the●correct●GMT●in●order●to●know●where●the●meridian●and●the●horizons●are●in●terms●of●right●

ascension●values.●●●From●the●main●menu,●you●can●always●check●the●4=Time/LST●button●to●verify●that●GMT●is●correct.

Incorrect GMT Offsets When Polling the Mount from the Keypad

(see p. 44)●●●Keypad●v.4.17●addresses●a●bug●with●the●3=Get●Time/Loc●FrMnt●command●in●the●2=Setup●●=>●●1=Locations●

&●Time●menu.●●●Earlier●versions●of●the●keypad●firmware●did●not●return●the●correct●value●for●the●GMT●offset●from●the●mount●

when●polled●from●the●keypad●in●eastern●time●zones.●●●This●problem●only●occurred●with●GTOCP3●control●boxes●because●

they●return●negative●numbers●for●eastern●offsets●whereas●the●older●GTOCP1●&●2●returned●text●for●the●negative●values.●●●In●

all●cases,●the●correct●values●were●being●sent●to●the●mount's●servo,●and●all●other●mount●functions●relating●to●the●GMT●offset●

were●handled●correctly.●●●Version●4.17●will●now●return●the●correct●values●for●all●time●zones●except●for●the●special●cases●

below.

Western Longitudes at Time Zone Zero

(see p. 44)●●●There●is●one●major●issue●that●remains●when●using●the●3=Get●Time/Loc●FrMnt●command:●●●Customers●in●

western●longitudes●who●are●in●time●zone●0●cannot●poll●the●mount●and●get●the●correct●offset●when●daylight●savings●time●is●in●

effect.●●●This●will●affect●customers●in●Great●Britain,●Portugal●and●West●Africa.●●●The●keypad●sends●the●correct●information●to●

the●mount●servo,●but●it●cannot●retrieve●it●correctly●at●this●juncture,●because●it●wants●to●apply●the●"west"●standard●to●the●"01"●

that●is●returned●from●the●mount.●●●This●erroneously●puts●the●offset●as●one●hour●behind●GMT●instead●of●one●hour●ahead●of●

GMT.●●●Customers●affected●by●this●bug●have●two●options●until●version●4.20●is●released:●1.●●Do●not●use●the●3=Get●Time/Loc●

FrMnt●command●when●daylight●savings●is●in●effect,●or●2.●●Keep●your●keypad,●computer●etc.●on●standard●time●so●that●the●

system's●time●always●equals●GMT.