How do I change the time in EQMOD ????

[steelfixer]

Following a thread I started on here today about my problems with an EQMOD driven goto mount we have come to the conclusion that the EQMOD has not reconised british summer time.

The net result is every time I slew to a target I end up 15 degrees short in RA.

I have searched through the setup but cannot find any way of altering the clock as it syncs with the computer clock.

Does anyone know how to tell it we are on BST.

Many thanks and multiple brownie points to anyone who can solve this.

Graham

[chrisshillito]

EQMOD doesn't care at all about daylight savings adjustments. EQMOD makes use of the PC's system time - this is not the displayed time you see on the windows clock but is something maintained behind the scenes by windows. System time is UTC and as such is no subject to daylight savings or timezone offsets. By using this UTC time and your site location EQMOD determines where it needs to point to reach a given RA/DEC.

Chris.

[steelfixer]

Hi Chris.

I was hopeing you were going to pick up on this.

I tried changing the clock on my computer by removing the BST option. It automaticly put the displayed time back an hour but when I looked at the clock in Cartes it point blank refuses to reset and still displays BST.

I therefore must assume that my computers internal clock is one hour fast hence the problem.

Can I change the internal clock on the computer?

thanks

graham

[chrisshillito]

Red herring I'm afraid - that's just something odd about CDC - no matter what, it knows the real time!. It does the same for me.

[malc-c]

By using this UTC time and your site location EQMOD determines where it needs to point to reach a given RA/DEC.

Chris.

So unless the user enters the correct details exactly for the location, some alignment error will occur. However I guess the information would have to be way out to get the error the OP was getting ?

[steelfixer]

Hi again Chris.

As the slew is 15 degrees out acording to calculations done by far cleverer people than me it means that I am one hour out on the time.

I manually adjusted the clock in Cartes last night and it moved the graphics on the screen far enough to make this error dissapear.

If I remove the daylight saving set up so my computer is set on European time ie. one hour slow will the Eqmod pick this up and so make the adjustments to elliminate the 15 degree discrepency.

thanks

graham

[chrisshillito]

If you remove the daylight savings the windows system time will be put one hour back (until we go into GMT) and all subsequent EQMOD slews with have a 15 degree error.

I manually adjusted the clock in Cartes last night and it moved the graphics on the screen far enough to make this error dissapear.

Not sure quite what you mean by this - are you saying that by default Cartes wasn't displaying the overhead sky correctly for your location and was an hour out?

In 5 years of EQMOD I've honestly never heard of anyone having to mess with the daylight savings to get EQMOD to slew correctly. There have been folks who reported similar issues to yours but these have always been due to incorrect site settings, failure to clear previous sync data, erroneous syncs etc. I am a little concerned that you are being led up the garden path by assuming that the error must be daylight savings related and that his will ultimately only serve to confuse further diagnosis.

Chris.

[steelfixer]

Hi Chris.

What is happening is this.

I tried to do a 3 star alignment using Cartes.

The first star was about 15 degrees out so I manually adjusted the scope to center it. I then synced this star and it placed the first point on the panel in eqascom.

I then slewed to the next star and it was again about 15 degrees out.

I centered the star using the mounts motors. synced this star and point 2 came up on the panel.

Tried to slew to Vaga for the third star and the maridian limit kicked in befor it even got there. Now this was only 2100hrs so vega was not over the Maridian.

Cleared everything in eqascom and tried again.

Every star I slewed to the scope stopped 15 degrees short in RA.

I then scrapped the idea of using Cartes and decided to use Eqtour.

I had exactly the same result with the tour every star came up 15 degrees short.

Even after centering and syncing when I went back to the same star it was still 15 degrees short in RA.

Hope this makes sense.

With ref to the clock in Cartes. When I manually changed the clock by 1 hour the screen changed to compensate for this alteration. With this alteration the whole sky image moved . By marking the telescopes position on my screen and adjusting the clock the difference in the 2 positions would take up the 15 degree shortfall I have when slewing.

Thanks

Graham

[malc-c]

Have you set the scope to the default home position before starting the alignment process. Have you also got the polar alignment correct ?. Unlock the RA and DEC and then In EQMOD select the Park to home position and once the mount has stopped slewing place the scope in the home position and lock it, then start the alignment process as above, but use the motors for all stars

[chrisshillito]

Graham,

I thought in the original thread you said the error was around 10 degrees - it seems that 15 degrees only came into the discussion later on from folks who had messed up using the synscan. Their particular error doesn't have to be related to your issue at all. If you have any doubt about the amount of size of adjustment you are having to make you could watch the change in RA (via the EQASCOM display) needed to correct the error.

Using Catres or EQTour sould make no difference - the goto command issued to EQMOD is simply interms of RA/DEC coordinates - so from a mount slew perspective it really doesn't matter what time settings Cartes is set to use (thought it makes sense to have it show the sky as it really is).

As I said in the other thread, an error in entering the EQMOD site settings could cause exactly the same problem - have you verified these are correct and that there are no extra hidden digits lurking in there.

What happens when you park to home - does it always goto to the correct position or is park position also out of place by 10-15 degrees?

Chris.

[steelfixer]

I stated 10 degrees in the other thread as an approximation it did not occure to me to check it out on the display.

I have checked double checked and then checked again my coordinates and they are correct.

I have the 'park' set up so the scope is a horizontal position so it fits under my obs roof. I have the unpark position set in the 'home' position. Both park and home always return to the correct position providing I have not altered the scope manually by releasing the clutches.

I have a gps mouse that I used on a pda sat nav that I am going to try, may be that will cure all my problems.

I am no computer expert by any stretch of the imagination but I am wondering this point.

This computer I use is a refurbished unit and to my understanding a lot of these come from the USA as they are prohibited from selling them there.

Could it be possible that the computers internal clock is still running on a different time zone, as in the one it was originally set up to.

Just a wild thought but I am now looking for any possible explanation.

It is now raining for the second night in a row so I cannot test anything else with regards to the exact degree of missalignment but I will check it out at the first oppertunity I get.

Thanks for your patience with me on this one but it realy is a mystery as to what is going on.

Graham

[malc-c]

Graham,

On the PC navigate to Control Panel and select "Regional and Language" settings - make sure that is set to UK for all options.

Chris mentions that EQMOD uses the system timer, maybe a simple utility such as Atomic Clock Sync Information from worldtimeserver.com might help sort out any windows time syncing errors?

[steelfixer]

Hi Malcolm.

My scope is set up in an obs on a pier.

It is perfectly Polar aligned and runs true and level throughout the full 360 degrees of rotation.

I start the alignment with the scope in the 'home' position which I set up using an industrial laser level which I use for setting up steel coloums and buildings in my business so I know it is within 0.001 of a degree of true.

[malc-c]

Hi Malcolm.

My scope is set up in an obs on a pier.

It is perfectly Polar aligned and runs true and level throughout the full 360 degrees of rotation.

I start the alignment with the scope in the 'home' position which I set up using an industrial laser level which I use for setting up steel coloums and buildings in my business so I know it is within 0.001 of a degree of true.

Probably more level than most professional observatories

[steelfixer]

Malcolm we seem to have overlapped.

I am hoping that by plugging in this gps it should take care of any differences in time and position and cure the problems once and for all.

I did read up on the gps facility on the Eqmod website and if I read it correctly once the system gets a gps fix it will automaticaly and permently correct any discrepencies that are there.

[steelfixer]

well its about time I used this expensive gear for something decent.

[steelfixer]

Mal-c you are a diamond.

I did as you suggested and went into the regional settings and all was set for the uk except the time sync update tab which was still set for the USA.

Poor old computer must have been well confused.

All I need now is a clear night to try it out.

Fingures crossed it is cured.

thanks

graham

[malc-c]

Graham, lets hope so

If in doubt that little app that I linked to will sync your system timing

[steelfixer]

Many thanks Malcome.

And thank you to Chris who will probebly have gone bald by now pulling his hair out with all my problems with Eqmod. Which I must state have all been self enduced.

[chrisshillito]

Many thanks Malcome.

And thank you to Chris who will probebly have gone bald by now pulling his hair out with all my problems with Eqmod. Which I must state have all been self enduced.

no need to worry about me pulling my hair out - it went of its own accord may years ago.

Chris.