Instruction manual

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longer travel without resetting the position count. If you find that you need a finer focus adjustment,
simply decrease the number of microsteps per count.
User Button Captions. This is where you insert labels for your four Remote Power Module channels.
These labels then appear on the main screen of RFCP.
Show Data. The Show Data button brings up a separate screen that shows the serial communication out to
the RoboFocus and back to the PC. This is useful in diagnosing problems in the system.
Focus Setup. The Focus Setup button brings up a screen in which you can record the name or description
of up to 20 different optical setups, and for each one identify the “correct” focus. Thus, if you change
optical setups, or use the RoboFocus control program for more than one scope, you can easily run the
focuser to the desired position (and then refine the focus, if needed).
Manual Full Travel Calibration.
You are now ready to calibrate the RoboFocus so that it will know the full travel of the focuser. You do
not have to do this to use RoboFocus, and it may be done at any time. However, calibrating is necessary if
you want to be able to have absolute focus position measurements (useful for returning to accurate focusing
if you have taken the system apart). It is also useful to know the full travel count so that you can set step
size to match your needs.
To calibrate the RoboFocus, use the OUT button to run the focuser all the way “out” (or at least as close to
all the way as you want). Release the OUT button, and turn off the RoboFocus. After ten seconds, turn on
the RoboFocus while pressing the IN button. The RoboFocus will read the IN button, will know that it is in
the training mode (it will beep five times). Let up on the button during the beeping. After the beeping
ends, the focus will begin running in without holding the button. When the focuser has moved all the way
in (or as far as you want it to go which may take several minutes), you may press either button to stop the
training run. When the motion stops, the RoboFocus records its position as =2 and will record the total
focuser travel as the number of steps run, and calibration is now complete. Thus, a count of 2 is the
innermost position. As the RoboFocus moves outward, the position increments by one for each step of the
motor. You can read the MaxTravel number of steps from the Configuration screen in the RFCP (you will
need to refresh the screen after calibration).
Typically, assuming a stepsize of 4 microsteps, the full travel for a R&P will be 2-4,000 steps, while the
full travel for a S-C may be as many as 100,000 steps. Because the RoboFocus has a maximum count of
65,000, if you have a S-C you will probably want to reset the step size to a larger number such as 8-32. If
you have a R&P, you may want a smaller stepsize. If you change the stepsize, you should retrain (to reset
the full travel counts) or go into Configuration/MaxTravel and manually enter a new number. In most
telescope setups, a stepsize giving a MaxTravel of 5-10000 counts still gives resolution that is as fine as
needed.
Note: you can operate the RoboFocus without training. However, because you have no absolute knowledge
of where the focuser is in its travel, you will not know the range of motion available. We recommend
training as a first step to assure that at least the approximate length of motion (measured in steps) is known
(record this in your log book).
Manual Menu.
Although the RoboFocus is designed primarily for computer controlled operation, most of the functions can
also be operated manually without a computer. (The major exception is that the backlash corrected motions
are only available under computer control). Simple IN/OUT movements are made by pushing the IN and
OUT pushbuttons. However, as we have already discussed, the pushbuttons also are used for direction
reversal and training operation.
In addition, the buttons allow access to the Manual Menu, which allows setting