Hi
There are pre-made cables available from
http://www.store.shoestringastronomy...roducts_eq.htm
But you need to specify the plug type on the mount.
The commercial one supplied by the above firm is a self contained DB9-DB9 "box" with the inbuilt RS232/TTL interface and is quite bulky.
If your mount has the RJ45 socket you will need a converter cable from DB9 to RJ45. If this is a cable then there won't be a large extension on the mount.
Next if you only have a USB port you will also need a USB/RS232 adaptor as well.
My suggestion for using the commercial RS232/TTL box is to connect this to the computer (using a USB/RS232 adaptor if necessary) and then a straight through DB9(m) to DB9(F) cable from there to the mount. or a DB9(F) to RJ45 cable.
Of course you can also make your own self contained unit as well.
See attached PDF
Barry