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I'm trying to set up a guidescope system and I have a question about the configuration. The setup will be guidescope/camera/usb/laptop. The laptop will run PHD and communicate to the EQ6 Pro mount via usb-serial dongle/serial cable/serial-RJ11 cable/Synscan Handset/mount.The mount is selected as ASCOM EQ6 in PHD, and connects sucessfully.

In this configuration PHD triggers the EQMOD interface when the ASCOM option is selected in 'scope'. This is where I'm not sure. Does the PHD/EQMOD interface know it is communicating through the handset and not a guideport, so ST4 pulse type commands are not needed, or do I need a rs232/guideport adapter to convert to ST4 output and plug into the guideport, or are there some options/selections in the EQMOD setup that I need to select?

Any suggestions would be helpful while I wade through the documentation.

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I'll probably get this a bit wrong but someone will correct it.

You can guide the EQ6 Pro by sending guiding commands to the ST4 port. That is what I do. For slewing, I have an EQDIR module that sits between the USB <> Serial adapter and the DB9 port (same as you I think) AND for guiding, a GPUSB adapter that sits between the ST4 port and a USB port. In PHD I select "GPUSB" for the mount. This sends specific guiding commands to the mount.

Alternatively, you can pulse guide. This does not use the ST4 port at all and the guiding commands go down the same wire as the slew commands ie EQDIR etc. These are little "up a bit", "left a bit" type commands. I think you select ASCOM in PHD to make this work. As I understand it, both EQMOD and PHD connect to ASCOM at the same time quite happily.



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OK, thanks for that. I guess I'm using the mode described in your second paragraph, ie pulse guiding direct through the handset. Are there any special selections or options you have to set in this mode in either PHD or EQMOD, or is selecting ASCOM as the PHD mount driver enough?

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Ah sorry, I must have been half asleep when I replied earlier. You are connecting via the handset rather than using an EQDIR interface.

There are some functions that EQMOD provides that the handset doesn't support ie won't work via the handset but will work via EQDIR. However, the nature of pulse guiding is such that I'd guess it would work via the handset so you'd be OK.

I think you just choose ASCOM in PHD and be sure to tick the "Pulse Guide Support" box in the ASCOM set up dialogue for EQMOD (where you set COM port, latitude etc.). There are pulse guide parameters to set in EQMOD but I can't help you there since I have never used them.

It would probably be a good idea for you to join the Yahoo EQMOD group - there is loads of information and help there. Specifically on the pros and cons of pulse guiding.


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It sounds overly complicated to me, I just have an ST4 cable between camera and mount, then the USB from the camera to the laptop running PHD, the mount handset connects via a serial to USB converter and I use redshift 6 for my pointing/remote control of scope.

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Thanks for everybodys help. Last night I got the guide system checked out and operational using my main imaging scope and vista laptop, so that when I get my guidescope I have the system ready. The configuration was scope/camera/5m usb/laptop/PHD, laptop/usb-serial dongle/10m serial cable/serial-RJ12/handset/mount. In case it helps anyone else doing this, the main factors appeared to be:

- Align, slew scope to target, then track

- always use the same usb sockets each time for camera and mount usb/serial dongle. (separate, not both in the same one!)

- Check comm port assignments for camera and usb-serial dongle and ensure setups are using designated comm ports

- Setup guide camera comms/image focus first with camera viewing app (etAMCAP), then close viewing app.

- Select 'pc direct' mode on handset

- PHD: select camera/take dark at selected exposure time

- PHD: select mount/EQ6 ascom/Check RA Dec numbers are tracking to confirm connection

- With the mount setup and tracking, when you press PHD 'capture' the mount stops. Immediately press the siderial track button on the EQMOD control panel (displayed when you select EQ6 ascom) to reestablish tracking

- Click on guide star (may need to change exposure to find star/take new dark at new exposure)

- When green box on star, press the 'PHD' guide button

- Calibration take a few minutes, then the big green cross wires appear

- Sit back and admire the guiding!

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I think I see the reason for the confusion. OpticStar sell the PL130 as part of a bundle with the Shoestring GPUSB. The camera and interface have to be installed as I described earlier.

The reason I know is because I bought that bundle but unfortunately had to return the camera for a refund since it was not sensitive enough. I kept the GPUSB and use it with a DSI II.


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