C20 Focus Motor
---------------

November 14, 2009


The focuser on the C20's at Moore Observatory and Mt. Kent Observatory is the
same as the "Hedrick" focusser on the Planewave Optics CDK20.  The control
system may be slightly different, but this would illustrate the principles of
creating a driver for other focusers.


From Andre Paquette --

The key bit of information is that the focuser behaves almost 
exactly like one of the motor control devices outlined in chapter 4, so 
most of the basic commands in that section work with the focuser.  The 
big difference is that the focuser is on device 18 (0x12) instead of 
devices 16 and 17.

For example, an aux command to move the focuser forward at rate 5 would 
look like:
0x3b 0x04 0x0d 0x12 0x24 0x05 <cksum>

If you wanted to send the same command via the hand control interface it 
would look like:
'P', 0x02, 0x12, 0x24, 0x05, 0x00, 0x00, 0x00