• Let's wait a bit before going into the “Set limits” section.

• Reset position: will set the current position as in the middle of the defined (Min..Max) range; so it will become 10000 in the example. No actual movement involved!

• Reset Set new pos to : will set the current position to the value keyed at its right

• Reverse button's motion : please use this to make your focuser move as advertised, that is, so that In, Cont-IN, … etc buttons will move the focuser in the appropriate way.

Let's go now to the “Set limits”:

There are two ways to limit the focus motion, always with the aim of avoiding damaging the focuser, motor etc.

The first way: beginning from a position where we are near focus, give it a motion range. We can manage this entering direct values in the “Max pos” and “Min pos” fields just seen.

The procedure will be as follows:

• To focus approximately (with any method)

• Take down or memorize the current step number (let's say, 12345)

• If you want the range to be +/- 500 steps, in the configuration window intro 12845 as Max pos and 11845 as Min Pos.

This is the simplest way of working, and it is perfectly convenient for the majority of the cases.

Nevertheless, if:

• The focus point is very close to one of the physical limits of the focuser

• The telescope has the motor on permanently

• Or we simply want additional security,

we can indicate the program where, exactly, are the focuser limits

Since v3.5 software and 2.2 firmware, even physical limit switches can be used. Please pay a look at the last section, Advanced uses .

This is the second way.

After quitting the configuration window, we must move the motor (using the “OUT” or “Cont OUT” buttons already explained) until the focuser is almost completely out of its trajectory; once there, we go back to the configuration window and press the “Set outermost” button.

We go back to the main window pressing “OK” and let’s move the focuser, always with the buttons (“IN” or “Cont IN”), until it is almost at the maximum limit inside its trajectory.

In both cases, and in order not to the force the mechanism, a minimum safety margin, such as ½ millimeter will be enough.

Again to the configuration window and now we press “Set innermost” button.

And so it is. The system now knows the motion limits and will never get out of them. It is a simple process but, since the motor is rather slow, it can be boring to implement. By the way, the motion limits will not be enforced until both have been defined; once done, the “Max pos” and “Min pos” fields will be updated with the new values, and of course can be changed at anytime.

Back to our review by the configuration window, there are a few buttons left to describe:

The “Advanced parameters...” area, as it full name says, while powerful is also potentially dangerous. If you are sure you want to modify those, you'll have to press the “Enable modifications to these parameters”, then agree to a popup window, and you'll have full freedom.

All the modifiable fields have a “tooltip” (a short help message that will display as you pass your mouse pointer over it) that will help you find correct values, but let us insist again: do not change them unless you know for sure you must do it.

The most dangerous things you can do:

• Selecting a wrong motor type! (Lunatico, as of today, only supplies unipolar motors) : the motor may heat and permanent damage can occur, including risk of fire.

• Increasing the % Power while stopped: the motor will be energized while stopped, again will overheat and can result in permanent damage and even fire.

Basically, the type of motors:

• Unipolar: a standard stepper motor; Lunatico supplies unipolar motors, and Moonlite and Robofocus motors are also unipolar ones.

• Bipolar: a different type of stepper motors.

• DC: inexpensive motors, usually found on cheap focusers. No step position control. However, the Seletek will operate them simulating steps, obtaining very good results.

• Step & Dir: the controller will output these signals to an external motor driver. With this option we've opened the door to controlling any possible motor.

Regarding the motor mode, this is really simple: before firmware 1.5 (quite long ago), the Seletek controller drived motors in a fixed way; for Robofocus(tm) or Moonlite(tm) motors, a specially wired cable was needed.

Now we have improved the firmware and software so no special cable is needed. The configuration goes like this:

The “inverted” modes just step in the opposite direction – select inverted if your automated software is confused about what's IN and OUT.

For any other case please select the default “Lunatico” mode.