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HEQ5 Autoguiding - Which port do I plug into ???

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#1 Leigh

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Posted 03 June 2009 - 05:31 AM

Ladies & Gents

Probably a stupid question - I was under the impression that the autoguiding port on the mount itself was the one you wanted to use.. using the supplied com cable.

However, I am unable to connect via Ascom when this cable (or the longer one I purchased) is plugged in there. I hear the mount attempt to engage and then I get an error.

When I plug this cable into the SynScan hand controller I have no problems. I am using PHD for guiding and I get the small handbox window up so I can move the mount remotely.

Just to expand.. I am using the latest Ascom platform with the latest Celestron drivers which actually gives me a Synscan/Synta option in the property setup window.

Am I missing something?? Am I ok to use autoguiding this way??
I'll be using a DSI II Pro via PHD for guiding once my QHY8 shows up.

Thoughts and opinions pls

Leigh

#2 neptun2

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Posted 03 June 2009 - 06:27 AM

As far as i know the autoguide port is only if you use ST4 guiding. If you want to use this port you should either have dedicated guider which has st4 compatible output cable to put in the mount's autoguide port or you should buy shoestring astroomy's gpusb adapter. If you want to understand better the idea look at the orion starshoot autoguider. It has 2 cables going out of it. One goes to the mount's autoguide port and second goes to the PC's usb port to transmit the information from the camera to the guiding software. Then the guiding software calculates the needed corrections and transmit them back to the autoguider and then through the second cable to the mount's autoguide port. If you have only a camera and not dedicated autoguider you need adapter like gpusb so you can transmit the commands for needed corrections to the mount. Other option is to just connect to the pc through hand controller and use guiding through this connection without using the gpusb and autoguide port. I do not know the exact configuration that you need to make for this guiding to work so i hope someone ese can help you.

Edit: Here you can find some more information.
http://www.cloudynig...hp?item_id=1859

#3 rmollise

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Posted 03 June 2009 - 06:52 AM

Ladies & Gents

Probably a stupid question - I was under the impression that the autoguiding port on the mount itself was the one you wanted to use.. using the supplied com cable.

However, I am unable to connect via Ascom when this cable (or the longer one I purchased) is plugged in there. I hear the mount attempt to engage and then I get an error.

When I plug this cable into the SynScan hand controller I have no problems. I am using PHD for guiding and I get the small handbox window up so I can move the mount remotely.

Just to expand.. I am using the latest Ascom platform with the latest Celestron drivers which actually gives me a Synscan/Synta option in the property setup window.

Am I missing something?? Am I ok to use autoguiding this way??
I'll be using a DSI II Pro via PHD for guiding once my QHY8 shows up.

Thoughts and opinions pls

Leigh


Yes, you're missing something...the correct cable. ;) The cable you are using is only for serial computer connection to the HC. You will need an ST4 compatible cable, which will be connected to the autoguide port and to either the camera, if it has an ST4 output, or to a Shoestring style guideport adapter plugged into your PC.

You don't connect to the Autoguide port with ASCOM. It doesn't know a thing about ASCOM or serial data. Only connect to your mount with your guide program using ASCOM if you are doing serial guiding (using, for example, the cable that came with your mount plugged in to the base of the HC; that cable is NOT for the autoguider port).

For ST4 guiding, you'd choose that or similar in your guide program setup.

#4 Leigh

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Posted 03 June 2009 - 07:19 AM

Ok.. thanks for the answers.. so just to clarify

It's ok to use a camera (DSI) with PHD and have PHD do all of the autoguiding calculations and send the controls via the handbox?

Or is it better to get the guideport adapter and have the DSI plugged into that and then into the AutoGuide port on the mount.

Its rather confusing

#5 jrcrilly

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Posted 03 June 2009 - 08:59 AM

Ok.. thanks for the answers.. so just to clarify

It's ok to use a camera (DSI) with PHD and have PHD do all of the autoguiding calculations and send the controls via the handbox?

Or is it better to get the guideport adapter and have the DSI plugged into that and then into the AutoGuide port on the mount.

Its rather confusing


It can be confusing.

Here's the deal. The DSI is a camera. It doesn't know what is in an image it captures, and it doesn't know what autoguiding is. You connect the camera to a computer and that computer controls the camera to capture an image and analyzes the image do determine whether guide corrections are necessary. That's what PhD does. It then sends corrections to the mount.

The corrections can be sent in the form of serial character strings which are decoded by the mount's electronics as commands to shift the mount. Such serial communications use communications ports on the PC and mount and a communications cable. That's what you have connected now.

The corrections can also be sent as simple pulses (East, West, North, South). These pulses would be sent to an autoguide port and used directly; no decoding involved. This is not communications, it's just one switched input line for each of the four possible guide correction directions. You could connect four pushbuttons or a joystick to the port and guide manually with no PC involved at all. Such ports are generally used with cameras with dedicated autoguide outputs; the guide signals don't go through a PC. It's possible to use a DSI and PhD via a PC and still use the guide port but that requires additional hardware. The problem is that a PC has no switched outputs available. It's necessary to synthesize them from commands issued via a communications port on the PC. This is what the GPINT and GPUSB devices do.

#6 rmollise

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Posted 03 June 2009 - 05:17 PM

Ok.. thanks for the answers.. so just to clarify

It's ok to use a camera (DSI) with PHD and have PHD do all of the autoguiding calculations and send the controls via the handbox?

Or is it better to get the guideport adapter and have the DSI plugged into that and then into the AutoGuide port on the mount.

Its rather confusing


Either way works fine.

#7 groz

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Posted 03 June 2009 - 10:50 PM

We have guided the heq5-pro using a dsi in the guide scope, then letting phd talk 'ascom' to the mount over the serial connector (the one in the hand controller). We have also guided it using a qhy5 camera, which has the st4 outputs, so then _another_ cable goes from the camera to the autoguider port, and the serial connection to the mount becomes optinal.

Both work, and for us, both work well.

#8 neptun2

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Posted 04 June 2009 - 02:59 AM

Best way is to try guiding through ascom and then if you have problems this way to try st4 guiding.

#9 John J

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Posted 04 June 2009 - 06:16 AM

The guide port on the telescope is looking for simple on / off signals like if you were pushing the direction buttons on your hand controller.

Dedicated guide cameras have a ST 4 out put and have optically isolated relay systems built into them. Basically it is like there is an on off relay between the camera and the mount for each direction button on the controller. They send the position of star image to the PC via USB and the PHD calculates the amount of correction. The PC returns correction command to the camera via USB, then the camera pushes the direction button for proper correction via the ST 4 connection to the guide port on the mount.

In the case you are describing, the camera has no ST 4 out put so it has to send the star imjage information to the PC via USB, PHD calculates the correction needed and then the PC has to send the direction correction commands to the mount via USB on the Shoe String GPUSB cable to guide port on the mount. The GPUSB cable has the optical isolator relay module built into it providing the ST 4 interface.

Hope this helps you understand the guiding process.

JJ

#10 rmollise

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Posted 04 June 2009 - 08:19 AM

Best way is to try guiding through ascom and then if you have problems this way to try st4 guiding.


Well, I can GUAR-RON-TEE you'll have problems with autoguiding the first time out. That's the nature of the beast. But I have never noted any difference between serial/ST4 guide quality. I guide ST4 because that's what I've always done and it seems a little simpler to me. But not better.

#11 Bowmoreman

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Posted 04 June 2009 - 11:10 AM

Best way is to try guiding through ascom and then if you have problems this way to try st4 guiding.


Well, I can GUAR-RON-TEE you'll have problems with autoguiding the first time out. That's the nature of the beast. But I have never noted any difference between serial/ST4 guide quality. I guide ST4 because that's what I've always done and it seems a little simpler to me. But not better.


there is ONE exception to Rod's "guarantee":

Use a dedicated ST4 or STV from SBIG... I did (STV) and I was (and still am) able to get successful guiding FIRST time out...

it just works... ;)

clear enough skies






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