Quote:
Originally Posted by Terry B
The plug on the EQ mount might look like a serial port as it is a DB9 plug but it isn't a serial port. The EQDIR that I have is one of these.
http://www.store.shoestringastronomy...ages/eqdir.jpg
You use a normal serial port from the puter in the front and plug the other end into the mount. This requires a serial port on the puter or a USB to serial adaptor. Not all of these adaptors work. I bought 2 different cheap ones of ebay as trials and neither worked. I eventually bought a pc board with 2 serial ports on it. This works very well.
The other is to use one of the usb to EQMOD cables from here.
http://www.astronics.nl/astronics/index.html
I have no knowledge of them but do know that the cable has some electronics in it. You can't just replace the end of a USB cable. |
Yep, that's a DB9 plug - it can be used as a plug of course
- be it for serial (which is what it is used quite commonly) or for any other purpose that one can imagine to use a plug for - eg the mount's handcontroller port (which of course is not RS232 serial)!
The EQDIR unit is a built device which is nothing more that a TTL-RS232 convertor only; housed in a case with easy interface DB9 male/female ports, but no USB/serial conversion so you need another interface viz: a USB/Serial adaptor (if the PC does not have a serial port) between it and the mount in order for the comms to work - the mount's handcontroller port requires a certain level of voltage that the standard RS232 outputs are not compatible with hence the need to have the TTL-RS232 conversion (usually thru use of a Max232 chip) - the solution that the EQMOD group used to overcome the comms issue between RS232 signals from the PC to the mount
The dontronics one has the built-in FTDI USB-serial/TTL-RS232 convertor so it means that you should be able to then interface the "free" end (not the one which is USB) to a DB9 or DB25 (the older bigger serial) plug and in this case it is for RS232 serial connections only to your mount and voila it should allow comms between the computer and the mount! Much cleaner and less one more extra adaptor to contend with
These FTDI ones come ready fitted with DB9 plugs, with header blocks only and free ends - so you can pick whatever type you want
I have both - ie I built one following the EQDIR style requiring the USB/Serial adaptor (when I just started into the hobby) and one that is the the complete FTDI USB-serial/TTL-RS232 cable (a-la starstuff.com.au) - pick your choice, they both should work and they do in my case
Cheers
Bill
