I am having some trouble with my mount and the problem only shows up when I hook up the ST4 cable to my STT-8300. When I connect a different camera from another manufacturer this does not happen. In order to help the mount manufacturer trouble shoot the problem, I need some information. First of all, the mount manufacturer designed their mount to reject slew commands when input is detected from ST4 port, this was done to avoid accidentally loosing the target when you are trying to auto-guide. When I hook up my STT-8300, autoguiding via ST4 works as normal, but the mount stops slewing as if it is receiving commands from the camera. I then went on to connect a different brand camera and the mount worked fine with no issues. So I contacted the manufacturer and they asked me for information about the ST4 port pin-out on the camera. They don't have an STT camera to test with, they have an STF camera. Also, is there any extra information I can provide them with that would help them trouble shoot this problem? I hope you can help me with this issue. Thank you
We recently had a few defective tracking interface cables go out. Try a different cable if you have one. If it needs replacing please contact Bill.
Unfortunately I have already confirmed it is not the cable as I have used 3 different cables, one of them from a different company. Strange thing is, guiding works perfectly,which I believe wouldn't have been the case if camera was shorting the st4 port.
If guiding is working, then I can't explain it. Maybe it's a ground loop or something? You'll have to talk to your mount manufacturer.
One last question, The mount manufacturer has responded that the problem is that the pin out of ST4 port for SBIG cameras is different from other cameras Does this make sense? I would have thought that if the pins were that different it would not have worked at all. Here is the chart he sent me. Atik ST4 pdf Manual pag 7 ---- Sbig ST4 pdf Manual pag. 31 Atik and others --------- SBIG Pin Description --------- Pin Description 1 Not used --------- 1 RA + 2 Common --------- 2 DEC + 3 RA - --------- 3 DEC - 4 DEC - --------- 4 RA - 5 DEC + --------- 5 Common 6 RA + --------- 6 Not used
Ironic... "ST4" refers to the iconic SBIG ST-4 autoguider. So the standard was devised for us! There are two ways to build the RJ-11 (actually RJ-12) cable. That difference is reflected in your diagram. I don't know how other camera manufacturers build their ports, but ours are documented in the manual.
