GPUSB Connection to LX200 Classic

[Keith]

Hi,

I am about to purchase a GPUSB and have a few questions. I intend to guide a Meade LX200 Classic with a Meade DSI II camera. I have read posts and the instructions regarding the RJ-12 cable but am still a bit confused. The instructions on the web site say the straight cable is the one to use, but there is also a note regarding the LX200 classic that has me confused.

So my first question is do I use a:

a) Straight through 6 pin RJ-12 cable (pin 1 to pin1, pin 2 to pin2, etc)
b) Crossover cable (pin 1 to pin 6, pin 2 to pin 5, etc)
c) Some other cable.


2) The scope currently communicates with the computer (SKY6) via the RS232 port. So I assume that the cable from the GPUSB connects to the CCD port – correct? I ask this because I have seen posts were a connection was made to the RS232 port, but this may apply only to the newer GPS scopes.

3) So when all set up, are the proper connections:

a) DSI II Camera to computer via USB cable.
b) Computer to scope via serial port to RS232
c) Computer to GPUSB via USB connection, cable from #1 above from GPUSB to CCD port on scope.


Thanks,

Keith

[dpanderson]

Hi, Keith.

The note regarding the LX200 Classic on our webpage refers to information in their manual that has confused people in the past. The bottom line is that our GPUSB and our pin 1 to pin 1 RJ12 cables (GPFC-7, GPFC-14, GPFC-25, GPCC-5 or GPCC-7) will work just fine with this mount.

2) Yes, the GPUSB connects to the CCD port on the mount.

3) The connections you note in your point 3) are correct.

Nice work!

[Keith]

Thanks Doug. My order just went in.

Cheers,

Keith

[Keith]

Hi,

I previously asked a cabling question regarding connecting the GPUSB to an LX200 Classic mount. I think I interpreted the answer incorrectly in that I thought the cable was a straight through cable instead of a cross over cable. I think my misintepretation resulted from my incorrect labeling of the cable types in my question.

Now that I have the GPUSB in hand, I can see that a straight though cable would have pin 1 on the GPUSB connected to Pin 6 on the LX200 mount since the input jacks are mirrored. Pin 1 on one end of the cable is therefore connected to pin 6 on the opposite end of a straight through cable - is this correct?

Before making any connections, I wanted to be certain of the cabling. It appears to me that a cross over cable is what is needed to connect pin 1 on one end to pin 1 on the other end of the cable Is this correct?

I have previously autoguided the LX200 Classic with an Orion SSAG autoguider, and this setup uses a cross over cable. I am now going to guide with a Meade DSI II. I do have both cable types – I just want to be certain that I am using the correct one with the GPUSB/DSI setup. I guess another way of asking – are the GPFC-7, GPFC-14, & GPFC-25,on the website cross over or straight through cables? Since Doug mentioned that these would work with my setup, then they are the type I should use.

Thanks for clarification.

Keith Graham

[dpanderson]

Keith,

Page 5 of the Orion SSAG Manual (or page 3 of this PDF file http://content.telescope.com/rsc/img/ca ... /29324.pdf) shows that the pinout of the SSAG is the same as the pinout of our GPUSB (http://store.shoestringastronomy.com/gu ... cables.pdf). Thus, it is my belief that whatever cable you used with your SSAG should also work with the GPUSB. It is also my belief that our pin 1 to pin 1 cables (GPFC-7, GPFC-14, GPFC-25, etc) should work too.

I avoid the use of the terms "crossover" and "straight through" because I have seen these used in different and confusing ways. I believe that by calling them "pin 1 to pin 1" or "pin 1 to pin 6" there should be no confusion at all as to how they are wired. If you hold both ends of the cable next to each other in the same orientation, then look at the order of the colored wires within, it should be obvious which way they are wired. If the colors go in the same order, then they are pin 1 to pin 1. If the colors go in the opposite order, then they are pin 1 to pin 6.

[Keith]

Hi Doug. What I call a "straight through" is when I stretch the wire out flat with both plug clips down, the white cable goes straight through (does not cross over to the opposite side). The clip side of both plugs is on the ribbed side of the flat wire. So, if I plug one end of this cable into the GPUSB with the cable clip down, the white wire is the first wire on the left - pin 1. When I plug the other end into the LX200 panel cable clip down, the white wire is on the right side of the jack or pin 6. So this is my confusion. When the first (white) wire is run straight through, the ends connect to opposite pins.

I think it would help me if you could tell me if the clips on your cable plugs are on the same side of the wire or on the opposite side (i.e. 1) both on the ribbed side or flat side or 2) one on the ribbed and the other on the flat side). That should clear up my confusion.

Thanks for your help,

Keith

[dpanderson]

Our cables are built with one on the ribbed and the other on the flat side.

It does get confusing!

[Keith]

OK! Great! That is what I thought. Your cables are what I have always interpreted as cross-over cables, and that is the only way pin 1 at one end will get connected to pin 2 at the other end.

I read a previous post (a rather lengthy one) from a year or so ago about ST4 cables. I use an STV to guide another scope, and this one uses the straight through cable. I learned from that post that SBIG has their pins reversed, which explains the difference between cables used with SBIG products vs others like GPUSB.

It was along way to go, but we finally got it:) .

Thanks so much for the clarificaton.

Cheers,

Keith