Quite A Learning Curve


CandCShaw
 

Enjoy Rusty!!!!

Chuck


On Apr 29, 2021, at 9:29 AM, Rusty Fletcher <rusty@...> wrote:



[Edited Message Follows]

Thank you for your reply Paul,

Good Idea! After I get the the new servo motors mounted, electronics installed, and all the software running on one computer, I will star test everything and check the Task Manager performance tab. The upgrade may take a month or more. I haven't started yet. When I'm doing an upgrade like this I like to take my time and work carefully. Right now I am thoroughly studying everything so I understand how the new servo system will work. I appreciate you guys advice.

Thank you,
Rusty


Rusty Fletcher
 
Edited

Thank you for your reply Paul,

Good Idea! After I get the the new servo motors mounted, electronics installed, and all the software running on one computer, I will star test everything and check the Task Manager performance tab. The upgrade may take a month or more. I haven't started yet. When I'm doing an upgrade like this I like to take my time and work carefully. Right now I am thoroughly studying everything so I understand how the new servo system will work. I appreciate you guys advice.

Thank you,
Rusty


paul K
 

The concept of multi threaded application software and computer processors running at many millions of instructions per second means that for all intents and purposes, the processes in the machine (cameras, mounts, guide camera, etc) run concurrently, with no interference between them. Your guide cam and main cam can download simultaneously with no delay /lag to other processes. The computer processor(s) switches between the processes to ensure they are serviced effectivley.

'Simultaneous' is not entirely technically true and depends on many things, but the huge processor and bus (internal data transfer ) speeds mean the tasks you need to perform in terms of astronomy gear (mount, camera, guide camera, rotator, dome and shutter robotics, add anything you like to this list) means that your computer's capablity is barely taxed. The amount of downtime the processor has is huge (even when it is simultaneously downloading a hi res image and a guide cam image) - you can see this for yourself on a Windows computer by running Task Manager and looking at the performance tab.

USB connectors can be daisy chained if you don't have enough on the laptop, just buy as many usb hubs as you need. I use two four port hubs to connect eight items of gear to my old (2001 vintage) Dell with 4 GB RAM.

Going back to your dual core laptop. My Toshiba dual core with 4 GB of RAM ran Sitech, PHD2 guiding, image capture software, my dome control robotics, and played youtube videos simultaneously.

you won't have any computer capacity problems with a single computer running all your gear.

good luck with it.
Paul


Rusty Fletcher
 

Hello Don,

I have been trying for over a week to fully understand this? You said " Pulseguide measures the error and sends a required correction in terms of arc-sec to the controller (inside the PC)". My question is: How does Pulseguide measure the error? Doesn't the guiding camera (not the main imaging camera) have to take an image (1 or 2 sec exposure), download that image to the computer, then PHD analyze the amount of error correction that needs to be done, and then send a correction to the SiTech controller? It seems to me if I have only one computer constantly downloading small images (I use a Meade Deep Sky II camera for auto-guiding on a second guide-scope) every 3 or 4 seconds, and (that same computer) downloading high resolution color images from my ZWO ASI533 camera through a USB 3.0 cable every 20 to 40 seconds, and that same computer running planetarium software (The Sky 6.0), things are going to start lagging and running slow. And, sometimes there will be delays between the computer trying to download auto-guiding images and trying to download the main images at the same time, which will cause lots of tracking problems. For ALT/AZ auto-guiding I like for my guiding corrections to occur in less that 5 second intervals. That is when I get the best images. I usually take about 200 or more images of one deep space object and stack them. Attached is an image I did recently.


paul K
 

just to add that you probably will need a usb hub (or two) I used unpowered ones and provided separate power supplies to my gear, but I believe that USB 2.0 can supply up to 500mA through the USB cable if you have devices which can be powered in that way.
Paul


paul K
 

I would concur with others on this, one dual core 2GHz laptop with 4G RAM and WIn 7 will be absolutely fine. I ran all my systems from a Toshiba laptop with that spec up until three years ago. The only reason I changed was because the laptop was returned to its owner! I ran Sitech, Sequence Genarator Pro, PHD2, my SBIG Camera and guider, Pyxis rotator and Cartes Du Ciel simultaneously. Worked a treat.

best wishes
Paul


Don W
 

Hi Rusty,
That thinking doesn't apply now to ASCOM  guiding using PulseGuide, which SiTech uses.  Pulseguide measures the error and sends a required correction in terms of arc-sec to the controller (inside the PC), then SiTech controller moves the mount (quickly) to correct the error.  Guiding responses are now quicker than ever before.

Your old way required a timing correction pulse via the comm port to make the correction, and that was easily interfered with by other comm activity.  All that is ten year old technology that isn't a problem anymore.
Don W


Rusty Fletcher
 

Thank you for your help Don! The only reason for using two laptops is that when I used Mel Bartels software the tracking was always better (resulting in better images) when I used two laptops. The guide scope software was able to update the guiding corrections faster (because it was running on a dedicated laptop) and nothing interrupted the download of my primary imaging camera because that was also happening on a dedicated laptop. In practice everything seemed to just work better and faster when I set up two laptops. Also I am using two older laptops, both of them are: Core 2 Duo Processors @ 2.2 GHz and 4GB RAM running Windows 7.


Joshua Hufford
 

Hi Rusty, I'm thinking the same thing as Don. Why would you want to use two PCs for this? No reason you can't do it from one and make things much simpler. 

Josh

On Thu, Apr 22, 2021 at 9:21 PM Don W <westergren@...> wrote:
Hi Rusty,
Welcome to the SiTech world.  It is so easy to do all that from a single PC or laptpop.  I really doubt you can connect to two PC's with a comm splitter, but you are welcome to try.
Don W


Don W
 

Hi Rusty,
Welcome to the SiTech world.  It is so easy to do all that from a single PC or laptpop.  I really doubt you can connect to two PC's with a comm splitter, but you are welcome to try.
Don W


Rusty Fletcher
 
Edited

I have used Mel Bartels stepper motor telescope control system for more than 20 years. I recently decided to upgrade to the SiTech servo motor system. I purchased the motors and electronics about a week ago and have not yet done the physical upgrade to my scope. I am studying the manuals, help files, and currently trying to familiarize myself with the software and everything I need to know to control my telescope with this new system. Do I understand correctly that I can connect two laptops to the same serial port, at the same time, on the SiTech Servo 1 controller using a straight through DB-9 Serial "Y" splitter? The reason I am asking is I would like to run SiTechExe connected to the Servo 1 controller, and control my primary imaging camera with my first laptop, while running my guide scope software (PHD) and sending ASCOM guide commands directly to the Servo 1 Controller from a second computer. Can this be done simultaneously? Thank you for any advice!

Rusty F.