Date   

Re: GTOCP4 Control Box

Donald Gaines
 

Even better Tom, and I see the advantage to it being powered. 
Thanks,
Don


On Thursday, February 25, 2021, Tom Blahovici <tom.va2fsq@...> wrote:
Great.  One other thing about this hub is that it uses 12V just like most astro devices.


Re: GTOCP4 Control Box

Tom Blahovici
 

Great.  One other thing about this hub is that it uses 12V just like most astro devices.


Re: GTOCP4 Control Box

Donald Gaines
 

Thanks Tom,
Looks like what I’ll need.
Regards,
Don 


On Thursday, February 25, 2021, Tom Blahovici <tom.va2fsq@...> wrote:
The USB hub I use is this one:
https://www.ebay.com/itm/I-Tec-Metal-Active-Hub-10-Port-Usb-3-0-With-Ps-Win-Mac-Os-NEW/274542884289?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2648

I've been using it for the last two years.  I only image in the winter and it works without issues down to -25C.  Not cheap though but perfectly sized for putting on a scope.  It fits between the dove tail and the scope itself.
I do run the camera direct to the NUC though.  It's pretty finicky about cables and hubs.


Re: GTOCP4 Control Box

Tom Blahovici
 

The USB hub I use is this one:
https://www.ebay.com/itm/I-Tec-Metal-Active-Hub-10-Port-Usb-3-0-With-Ps-Win-Mac-Os-NEW/274542884289?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2648

I've been using it for the last two years.  I only image in the winter and it works without issues down to -25C.  Not cheap though but perfectly sized for putting on a scope.  It fits between the dove tail and the scope itself.
I do run the camera direct to the NUC though.  It's pretty finicky about cables and hubs.


Re: GTOCP4 Control Box

Donald Gaines
 

Thanks for the info Tom,
Great setup. The hub you mention, it is a USB hub, and do you know the brand and part number of the hub?
Regards,
Don


On Wednesday, February 24, 2021, Tom Blahovici <tom.va2fsq@...> wrote:
Hi Donald,
This is my setup.  Since you have a ROR setup you have a lot more space than me.
My mount is still an older AP600 but it has the latest CP4 controller. If you look at the picture of my "observatory",  you will see a little box to the left of the observatory under the wood platform.  In there is a 12V power supply, an Ethernet hub, and an IOT power bar.
The Ethernet hub connects to an I5, Intel NUC running Windows 10 Pro and is accessible via Remote Desktop. The NUC has a few USB ports and one connects to a hub mounted on the telescope itself.  The hub provides connectivity to an ASI6200mm, filter wheel, an ASI290mm off axis guider, and a Moonlight Nitecrawler focuser.
The CP4 itself uses an ethernet connection from the hub.  The NUC is very versatile and also has a Thunder bolt interface.  I use that with a Thunderbolt to 10G ethernet adapter.  Gives me 10 times the throughput of a standard gigabit Ethernet connection.  Pretty useful with the 125Mbyte images of the ASI6200.
The NUC is really good.  Will last a long time.
My observing session goes like this:  I turn on the computer and equipment remotely using my IOT phone app to let it warm up and get ready. This connection also has a couple of heaters (Golden Rod heaters to keep the "observatory" warm. These are then turned off).  I go outside, unlock the cover to my Observatory and lift off the cover.  It is made of foam and aluminum angle strips and weights 15 pounds. It is covered in Dacron, and filler (same material used for aircraft wings) and is super durable (6 years and counting with Montreal weather).  I then go inside, connect to the NUC with Windows remote desktop, Open APCC, connect to the mount, and start Voyager.
Running in 5 minutes.  Can't wait until it's housing an Ap 1100
Tom


Re: GTOCP4 Control Box

Tom Blahovici
 

Hi Donald,
This is my setup.  Since you have a ROR setup you have a lot more space than me.
My mount is still an older AP600 but it has the latest CP4 controller. If you look at the picture of my "observatory",  you will see a little box to the left of the observatory under the wood platform.  In there is a 12V power supply, an Ethernet hub, and an IOT power bar.
The Ethernet hub connects to an I5, Intel NUC running Windows 10 Pro and is accessible via Remote Desktop. The NUC has a few USB ports and one connects to a hub mounted on the telescope itself.  The hub provides connectivity to an ASI6200mm, filter wheel, an ASI290mm off axis guider, and a Moonlight Nitecrawler focuser.
The CP4 itself uses an ethernet connection from the hub.  The NUC is very versatile and also has a Thunder bolt interface.  I use that with a Thunderbolt to 10G ethernet adapter.  Gives me 10 times the throughput of a standard gigabit Ethernet connection.  Pretty useful with the 125Mbyte images of the ASI6200.
The NUC is really good.  Will last a long time.
My observing session goes like this:  I turn on the computer and equipment remotely using my IOT phone app to let it warm up and get ready. This connection also has a couple of heaters (Golden Rod heaters to keep the "observatory" warm. These are then turned off).  I go outside, unlock the cover to my Observatory and lift off the cover.  It is made of foam and aluminum angle strips and weights 15 pounds. It is covered in Dacron, and filler (same material used for aircraft wings) and is super durable (6 years and counting with Montreal weather).  I then go inside, connect to the NUC with Windows remote desktop, Open APCC, connect to the mount, and start Voyager.
Running in 5 minutes.  Can't wait until it's housing an Ap 1100
Tom


Re: GTOCP4 Control Box

Donald Gaines
 

Thanks Christopher,
I’ve got one PC to dedicate to it already with an SSD drive, looks like I’m going to need another.  I’ve heard of the Toughbook before, it seemed to be highly recommended. With what I’ve been seeing on the Forum about conditions like temperature, it would seem like a Toughbook would be a great choice. Thanks for the suggestion.
Regards,
Don Gaines


On Wednesday, February 24, 2021, Christopher Erickson <christopher.k.erickson@...> wrote:
I'm not sure which one of us enjoys his job more. We are both engineers doing what we love most. Be damned the dollars. We are having too much fun doing fascinating engineering stuff while making new friends whenever we can.

As for your observatory PC details, I am a strong advocate for Panasonic Toughbook laptops with real serial ports and SSD hard drives. Laptops have real screens, keyboards, pointing devices and maybe most important of all, built-in UPS's. This saves a lot of time when tuning and troubleshooting. And can still remote control it from someplace else.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738
www.summitkinetics.com
   

On Wed, Feb 24, 2021, 1:05 PM Donald Gaines <onegaines@...> wrote:
Thanks Christopher,
That’s a great idea. I hadn’t considered that. I have been watching the forum for some time and see some very interesting threads from some really interesting people. I wonder who enjoys their job more, you or Roland.
Thanks for your advice.
Don Gaines 

On Wednesday, February 24, 2021, Christopher Erickson <christopher.k.erickson@gmail.com> wrote:
IMNSHO, set up a compact observatory PC next to the scope and then controle that PC remotely from the house.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Wed, Feb 24, 2021 at 12:50 PM Donald Gaines <onegaines@...> wrote:
Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: Encoders in the Mach2 vs 1100

Roland Christen
 


I would have thought that a bigger ring gives more space to mark a higher number of "ticks", hence giving higher resolution and so accuracy...
Resolution is not the same as accuracy.

There are 2^26 individual addresses (67,108,864) that can be accessed in the RESA encoder, whether it is 75mm or 100mm. Therefore the resolution is the same for both rings.

The stated accuracy is a measure of how accurate the encoder is over a 24 hour period of revolution (360 degree total angle of rotation). For the 75mm ring, accuracy would be approximately +-3.82arcsec/24hr or 0.16 arc sec per hour of tracking. For the 100mm ring it would be 0.12 arc sec. per hour.

In reality one can never get the ring to have zero runout, so the practical accuracy will come in at perhaps +-0.5 arc sec per hour, more or less. So whether you have a 100mm ring or a 75mm ring, it makes no practical difference. Star motion due to atmospheric refraction will be an order of magnitude higher if you are anywhere but at the exact zenith.

The way the RESA works is not like any other encoder system. It does not read "ticks" the way an ordinary encoder does. It reads a barcode that is imprinted on the steel ring. The barcode is read over a fairly large circumference angle. The readhead is a miniature camera, not a photodiode that registers black and white tick marks. It's really quite revolutionary how it works, and it does work splendidly for telescope mounts.

Rolando




-----Original Message-----
From: Seb@stro <sebastiendore1@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Wed, Feb 24, 2021 4:40 pm
Subject: Re: [ap-gto] Encoders in the Mach2 vs 1100

Hello Roland,

Your post made me take a quick look at Renishaw's spec for the Resolute extended temp encoder and I found two interesting observations (not related to the low temp version) which made me realize I'm probably missing something in my understanding of how the encoders actually works...

First, when we look at the following table, the "system accuracy" is increasing with the diameter of the ring (kind of opposite of what you stated earlier), which made sense to me since I would have thought that a bigger ring gives more space to mark a higher number of "ticks", hence giving higher resolution and so accuracy... So I assume the "system accuracy" of the encoder (which is defined as graduation + SDE by Renishaw) doesn't directly translate into the "tracking accuracy" of the mount.



Second observation, still looking at that table, the order of magnitude of that system accuracy seems to be more than ten-fold lower in comparison to the spec'ed tracking accuracy of the mount (+/- 3.82 arc-sec "system accuracy" for the 75 mm ring vs +/- 0.25 arc-sec "tracking accuracy" of the Mach2).

To explain these differences, my guess would be that some (gear/pulley) ratio somewhere does indeed make the tracking accuracy similar throughout the mount models and while at the same time increasing it by a factor of about 10X relative to the Renishaw's specs, but I wondered if there was more to it...

Am I lost in space ? 

Regards,
Sébastien


De : main@ap-gto.groups.io <main@ap-gto.groups.io> de la part de Roland Christen via groups.io <chris1011@...>
Envoyé : 24 février 2021 11:48
À : main@ap-gto.groups.io <main@ap-gto.groups.io>
Objet : [ap-gto] Encoders in the Mach2 vs 1100
 
Hello Astronuts,

To clear up any confusion about mount encoders, both Mach2 and 1100/1600 use the same Renishaw RESA high resolution encoders. The main difference is that the ring diameter of the 1100/1600 mounts is 100mm, the Mach2 uses a 75mm ring. Resolution and accuracy is the same for all. The readheads are the same RESA readheads, except that they are matched to their respective diameters, so that the 75mm readheads cannot be used on the 100mm rings and vice versa.

Roland Christen
Astro-Physics Inc.

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Re: GTOCP4 Control Box

Christopher Erickson
 

I'm not sure which one of us enjoys his job more. We are both engineers doing what we love most. Be damned the dollars. We are having too much fun doing fascinating engineering stuff while making new friends whenever we can.

As for your observatory PC details, I am a strong advocate for Panasonic Toughbook laptops with real serial ports and SSD hard drives. Laptops have real screens, keyboards, pointing devices and maybe most important of all, built-in UPS's. This saves a lot of time when tuning and troubleshooting. And can still remote control it from someplace else.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738
www.summitkinetics.com
   

On Wed, Feb 24, 2021, 1:05 PM Donald Gaines <onegaines@...> wrote:
Thanks Christopher,
That’s a great idea. I hadn’t considered that. I have been watching the forum for some time and see some very interesting threads from some really interesting people. I wonder who enjoys their job more, you or Roland.
Thanks for your advice.
Don Gaines 

On Wednesday, February 24, 2021, Christopher Erickson <christopher.k.erickson@...> wrote:
IMNSHO, set up a compact observatory PC next to the scope and then controle that PC remotely from the house.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Wed, Feb 24, 2021 at 12:50 PM Donald Gaines <onegaines@...> wrote:
Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: GTOCP4 Control Box

Donald Gaines
 

Thanks Yves and Mike,
I am going to follow your advice. Can’t go wrong with something that’s working for so many folks for such a long time.  I told Daleen at Astro-Physics it amazing how helpful and patient everyone is on the forum.
Thanks again,
Don Gaines

On Wednesday, February 24, 2021, Donald Gaines via groups.io <onegaines=gmail.com@groups.io> wrote:
Thanks Liam and Jeffery,
Looks like you all agree.  I looked up NUC and RDP, and I understand. Looks like I have some homework to do but this seems like something I can do. Liam, thanks for explaining the CP4 to me, I had a feeling it would not do what I thought it might. Thanks again for the advice. 
Regards,
Don Gaines

On Wednesday, February 24, 2021, Donald Gaines via groups.io <onegaines=gmail.com@groups.io> wrote:
Thanks Christopher,
That’s a great idea. I hadn’t considered that. I have been watching the forum for some time and see some very interesting threads from some really interesting people. I wonder who enjoys their job more, you or Roland.
Thanks for your advice.
Don Gaines 

On Wednesday, February 24, 2021, Christopher Erickson <christopher.k.erickson@gmail.com> wrote:
IMNSHO, set up a compact observatory PC next to the scope and then controle that PC remotely from the house.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Wed, Feb 24, 2021 at 12:50 PM Donald Gaines <onegaines@...> wrote:
Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: GTOCP4 Control Box

Donald Gaines
 

Thanks Liam and Jeffery,
Looks like you all agree.  I looked up NUC and RDP, and I understand. Looks like I have some homework to do but this seems like something I can do. Liam, thanks for explaining the CP4 to me, I had a feeling it would not do what I thought it might. Thanks again for the advice. 
Regards,
Don Gaines

On Wednesday, February 24, 2021, Donald Gaines via groups.io <onegaines=gmail.com@groups.io> wrote:
Thanks Christopher,
That’s a great idea. I hadn’t considered that. I have been watching the forum for some time and see some very interesting threads from some really interesting people. I wonder who enjoys their job more, you or Roland.
Thanks for your advice.
Don Gaines 

On Wednesday, February 24, 2021, Christopher Erickson <christopher.k.erickson@gmail.com> wrote:
IMNSHO, set up a compact observatory PC next to the scope and then controle that PC remotely from the house.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Wed, Feb 24, 2021 at 12:50 PM Donald Gaines <onegaines@...> wrote:
Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: GTOCP4 Control Box

Mike Dodd
 

On 2/24/2021 5:50 PM, Donald Gaines wrote:
outside in a structure with a ROR, and connect to a PC in the house
about 150 ft away. I was thinking of using the Ethernet port and I read
that it can also be done with a USB and Icron 2304 USB extender. I am
curious if cameras, focuses and other accessories can be connected to
the GTOCP4 and then be operated by the PC in the house? Is there a
preferred method for this kind of setup? I would appreciate any advice
you might be willing to pass along.
I have a PC in the observatory to keep thing simple. I have an Icron 2304 between the PC and the pier, a cable length of about 15 feet. It works great. Here are some factors to consider:

* The 2304 is USB 2 only, so if you have a USB 3.0 camera, image transfer will be significantly slower. I wanted high-speed image transfer, so I installed a powered USB 3.0 extender for the camera. Another reason for the PC to be in the observatory.

* My focuser, rotator, and guide camera go through the 2304, so the USB 2 speed is not an issue.

* My AP1200 connects to the PC via old-fashioned, reliable RS-232 serial.

* connect to the observatory PC from my house with Windows Remote Desktop via a 300-foot buried Ethernet cable. It works very well. I have the option of saving images to a Linux server in the basement via the same Ethernet link, or saving them on the observatory PC, then transferring them to a Win 10 computer for processing with PixInsight.

I highly recommend a PC in the observatory. As I said, it keeps things simple. I can do EVERYTHING from inside the house -- start the PC, open the roof, power-up and connect all the equipment, and start an ACP imaging plan.

--- Mike
http://astronomy.mdodd.com


Re: GTOCP4 Control Box

Yves Laroche
 

Hi Don,

Began with the same setup as suggested by Christopher in 2003.

Since ten years, I'm using exactly the same setup as you expect to use and it's working great.

Icron are very good products.

Regards,
Yves

Le 24 févr. 2021 17 h 50, Donald Gaines <onegaines@...> a écrit :
Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: GTOCP4 Control Box

Donald Gaines
 

Thanks Christopher,
That’s a great idea. I hadn’t considered that. I have been watching the forum for some time and see some very interesting threads from some really interesting people. I wonder who enjoys their job more, you or Roland.
Thanks for your advice.
Don Gaines 


On Wednesday, February 24, 2021, Christopher Erickson <christopher.k.erickson@...> wrote:
IMNSHO, set up a compact observatory PC next to the scope and then controle that PC remotely from the house.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Wed, Feb 24, 2021 at 12:50 PM Donald Gaines <onegaines@...> wrote:
Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: GTOCP4 Control Box

Jeffrey Wolff
 
Edited

I bought a NUC running Windows 10 Pro. It is very small and easy to park on the shelf on the pier. I connect the mount and NUC to a MikroTik router with 5 Ethernet ports and move the NUC in to the house when I am done. I use RDP with compression turned off to remotely control and monitor the mount, cameras, focuser, etc... It runs APCC, and all the astronomy imaging software. I use another computer in my warm house to control the NUC at the mount.

The guide camera, imaging camera focuser are all connected to a Pegasus Powerbox Advanced on the scope to provide USB and power. A single USB 3 cable and 12 volt power cable go down to the base of the mount and connect to the NUC and 12 volt power supply. I have a network connection from the MikroTik back to the house network.

The CP4 can be controlled using the Ethernet verses USB. It doesn't have any ability to connect to your cameras.


Re: GTOCP4 Control Box

 

I agree. A small observatory PC is the way to go here. I would add, Donald,

 

The CP4 isn’t a hub or splitter, so it cannot run any equipment other than the mount itself. If you managed to connect a camera to the CP4 (type B to type B USB cables are non-standard and hard to find!), they would simply look at each other waiting for instructions. Using a hub will let you connect all of your equipment.

 

Liam Plybon

Astro-Physics

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Christopher Erickson
Sent: Wednesday, February 24, 2021 4:55 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] GTOCP4 Control Box

 

IMNSHO, set up a compact observatory PC next to the scope and then controle that PC remotely from the house.


"My advice is always free and worth every penny!"

 

-Christopher Erickson

Observatory Engineer

Summit Kinetics

Waikoloa, Hawaii

 

 

On Wed, Feb 24, 2021 at 12:50 PM Donald Gaines <onegaines@...> wrote:

Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: GTOCP4 Control Box

Christopher Erickson
 

IMNSHO, set up a compact observatory PC next to the scope and then controle that PC remotely from the house.

"My advice is always free and worth every penny!"

-Christopher Erickson
Observatory Engineer
Summit Kinetics
Waikoloa, Hawaii


On Wed, Feb 24, 2021 at 12:50 PM Donald Gaines <onegaines@...> wrote:
Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


GTOCP4 Control Box

Donald Gaines
 

Hi folks,
I was lucky enough to be notified recently I’m going to be the proud father of an 1100GTO mount.  I have read through the GTOCP4 Operating Instructions as I plan on how to connect the mount to a PC, CCD Camera, focuser, and other accessories.  I would like to locate the mount outside in a structure with a ROR, and connect to a PC in the house about 150  ft away. I was thinking of using the Ethernet port and I read that it can also be done with a USB and Icron 2304 USB extender.  I am curious if cameras, focuses and other accessories can be connected to the GTOCP4 and then be operated by the PC in the house?  Is there a preferred method for this kind of setup?  I would appreciate any advice you might be willing to pass along.
Thanks,
Don Gaines


Re: Encoders in the Mach2 vs 1100

Sébastien Doré
 

Hello Roland,

Your post made me take a quick look at Renishaw's spec for the Resolute extended temp encoder and I found two interesting observations (not related to the low temp version) which made me realize I'm probably missing something in my understanding of how the encoders actually works...

First, when we look at the following table, the "system accuracy" is increasing with the diameter of the ring (kind of opposite of what you stated earlier), which made sense to me since I would have thought that a bigger ring gives more space to mark a higher number of "ticks", hence giving higher resolution and so accuracy... So I assume the "system accuracy" of the encoder (which is defined as graduation + SDE by Renishaw) doesn't directly translate into the "tracking accuracy" of the mount.



Second observation, still looking at that table, the order of magnitude of that system accuracy seems to be more than ten-fold lower in comparison to the spec'ed tracking accuracy of the mount (+/- 3.82 arc-sec "system accuracy" for the 75 mm ring vs +/- 0.25 arc-sec "tracking accuracy" of the Mach2).

To explain these differences, my guess would be that some (gear/pulley) ratio somewhere does indeed make the tracking accuracy similar throughout the mount models and while at the same time increasing it by a factor of about 10X relative to the Renishaw's specs, but I wondered if there was more to it...

Am I lost in space ? 

Regards,
Sébastien


De : main@ap-gto.groups.io <main@ap-gto.groups.io> de la part de Roland Christen via groups.io <chris1011@...>
Envoyé : 24 février 2021 11:48
À : main@ap-gto.groups.io <main@ap-gto.groups.io>
Objet : [ap-gto] Encoders in the Mach2 vs 1100
 
Hello Astronuts,

To clear up any confusion about mount encoders, both Mach2 and 1100/1600 use the same Renishaw RESA high resolution encoders. The main difference is that the ring diameter of the 1100/1600 mounts is 100mm, the Mach2 uses a 75mm ring. Resolution and accuracy is the same for all. The readheads are the same RESA readheads, except that they are matched to their respective diameters, so that the 75mm readheads cannot be used on the 100mm rings and vice versa.

Roland Christen
Astro-Physics Inc.

--
Roland Christen
Astro-Physics


Re: Clutch Knobs vs. the Gearbox Release Levers

M Hambrick
 

To Jeffrey's comment about loading his scopes with the mount in Park 3, I used to do the same thing until I read a suggestion to load them with the mount in Park 2. This made a tremendous difference, especially with the 180 EDT. Just make sure that the counterweights are installed before loading the scope. The other advantage to loading the scopes with the mount in Park 2 is that you can install the RAPAS if you have one and polar align after everything has been installed.

Mike

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