Losmandy Digital Drive users-ST4 compatibility question

[[1ponders]]

I've been playing around with my ST7 and self guide, as well as using the Shoestring Astronomy GPUSB adapter with other cameras to autoguide with and I'm having a bit of a scratch the head session with them.

I plug the ST4 compatible cable (straight through wiring that came with the SA GPUSB and the SBIG cable with the SBIG) into my hand controller port and it works np, except when I try to change guide speed settings. When I press the GS setting button the Guide Rate changes (ie, sidereal to king, to luna to solar and back to sidereal). Plus the TVC engages (I've never used the TVC settings as I have more success without it). When I press the Guide Rate button the Guide Speed changes. Nothing I do will turn off the TVC unless I unplug the ST4 cable and then change the TVC setting using its button. Once the cable is unplugged everything works normally.

Can anyone enlighten me as to what is going on and if it is possible to prevent these little annoyances from happening?

[Peter Ward]

Paul,

The .ttl outputs of the ST7 are not isolated.

You need to use SBIG's relay box.

Peter

[[1ponders]]

I tried a relay box Peter but the cable that came with my SBIG has no power plug to go to the Relay box. It only has 5 pins in the "D" type connector that attaches to the camera the 6th power pine isn't there. To confirm this there is no "clicking" in the relay box when self guiding is initiated.

[[1ponders]]

Just to make sure I have everything connected correctly, my connections are;

Relay Box D plug connected to the ST7 mount outlet, ST4 cable that come with the camera (RJ12 plugged into a dummy RS 232 style plug with only 5 pins) RJ12 plugged into the Relay Box and other end of the RJ12 plugged into the hand controller port

[DavidH]

Hmm,

I haven't had a problem changing guide speed when using the GPUSB with my Losmandy digital drive but then maybe I just haven't noticed.

Does the problem occur without the guiding cable plugged in?

Is the GPUSB actually issuing a guide command when you try to change the guide speed?

Is the problem the same with the handpad plugged in and one direction key on the handpad pressed continually?

I'm thinking that the guiding signal may be confusing the scanning of the guide speed/tracking rate/TVC buttons, causing the processor to think that a different button is pressed.

Regards,
David.

[[1ponders]]

David

No the problem doesn't occur when the guiding cable isn't plugged in.


No there are no command being sent when trying to change speed

I'm not sure what you mean by with the hand paddle plugged in and the Key press continually. Do you mean press the key and try to change speeds? If so I haven't tried that. I'll wait til this next shot finishes and I'll see how it goes.

[DavidH]

Yes, that is what I mean. I'm trying to simulate a continual guide signal and speed change simultaneously.

Regards,
David.

[[1ponders]]

I should rephrase what I wrote in post 3.

The cable that comes with my camera doesn't have a 6th power pin so when I plug in the relay box cable I don't think it is getting power to the relay box. From discussions with other, the relay box should click when the relays are activating during autoguiding, there is no clicking so I am assuming that it is not getting power from the camera

[JohnG]

Hi Paul

You don't have simultaneous guiding ticked in your software do you, I think you will find that is not supported, just a guess.....

Cheers

JohnG

[[1ponders]]

No John I don't, I've been caught out with that before though.

[JohnG]

Can't think of anything else other than a wrong cable, have you had a look here.

http://www.sbig.com/sbwhtmls/app_notes.htm

Cheers

JohnG

[[1ponders]]

I'm pretty sure I have the right cables. I'm using the one that came with the GPUSB and the one that came with the SBIG for that camera, but I'll check it out to make sure.

[JohnG]

The way I understand it is that the 9 Pin AO/SCOPE/CFW cable attaches to the camera, that is the one that came with it, the RJ11 plug goes into the RJ11 receptical in the Relay Adapter Box, the 15 pin DRC cable then goes to the Autoguider Port, connection is then made.

Cheers

John G

[[1ponders]]

Yep that's the way I had it but there is no power getting to the relay box. The 9 pin cable that comes with the camera only has 5 pins. The 6th pin that would carry power to the relay box is not there in the plug. My plug has a socket in the back that the RJ11/12 plug plugs into and the other end plugs into the relay box. The thing is my cable isn't a straight through. The layout of the wires on one end of the cable is reversed the other end, so I can't even be sure I have the cable around the right way. Holding the RJ plug so the tab is down, on one end white and black are to the left and on the other end white and black are to the right.

Yet on my GPUSB it is a straight through cable. :screwy:

[Peter Ward]

Paul,

Everything is behaving as it should... You are using the wrong type of cable.

[[1ponders]]

Which cable should I be using. The only cable that came with the Relay Box was the one that goes from the box to the hand controller port. Will I need to get a cable made up that has pin number 6 connected?

[Peter Ward]

SBIG relay boxes come with three cables (or at least should do) male 9 pin to RJ11 and female 15 pin to RJ11, plus a nine pin jumper.

Sounds like you need the 9 pin/RJ. It's called a TIC cable, and there is a diagram for it at SBIG's web site.

[[1ponders]]

That sound like what I'm missing Peter. I was just pointed to the SBIG site and found this little gem

Unfortunately mine only came with the one 15pin cable. I'll have to contact the original owner and see if he still has it.

[[1ponders]]

I've just checked Peter and I have the 15 pin cable that runs from the Relay box, and the circuit diagram calls that the TIC cable. I've not found any other reference of diagram for the special camera to adapter box cable that provides the power to the camera.

[Peter Ward]

OK...SBIG have changed a few things around since I last checked. You need this one then.

http://www.sbig.com/pdffiles/Relay_Adapter_Box_Cable3.pdf

We also sell them for $30. ;)

[[1ponders]]

Yep figured I was missing something. Cheers