Tele Vue Focusmaster User Manual

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If you have the Digital Indicator installed, turn it on by pressing the “set” button. Then in TVFocusPlus click the

“Read Continuously” button and you should see numbers appear in the “Focus Position” display box. Those numbers
should change when the motor is running provided the Digital Indicator is in contact with the Rest.

The following descriptions pertain to the function of each button, window and slider in the TVFocusPlus pro-

gram. Take a moment to familiarize yourself with the function of each and you will quickly discover the utility of
TVFocusPlus. The program is broken into two tabbed functions. They are “Run” and “Setup.” “Run” is the default,
and is the mode you will be using most.

Setup Tab

Connect Interface

Connect Interface
Should you start the TVFocusPlus software prior to connecting Focusmaster, the program will recognize that the de-
vice is not connected. Click “OK” and the program will start. After plugging in the USB cable the program still
needs to recognize the Focusmaster has been attached. Clicking the “Connect Interface” button will prompt a pop
up window verifying the Focusmaster has been found. Click “OK” and Focusmaster can now be controlled via
TVFocusPlus.
LED On / Off

LED On / Off

LED On / Off
Normally, the LED on the Focusmaster will be red, and change to green when the Focusmaster is energizing the mo-
tor. If you wish to extinguish the LED, click LED Off. Click LED On to re-enable the LED indicator.
PWM Frequency

PWM Frequency

PWM Frequency
Motors also behave differently as a function of the frequency used by the pulse-width modulator. This “radio button”
allows you to select one of three frequencies to further optimize the performance of your focuser motor. The 16x set-
ting provides a PWM frequency of about 25 kiloHertz, which is above most human hearing. Selecting 4x (about 6
kHz) or 1x (about 1.6 kHz) may provide better performance, but it may also result in more audible noise when the
motor is energized.
Motor Speed

Motor Speed

Motor Speed
The output of the Focusmaster is a pulse-width modulated voltage that can be varied from an average value of 5V
down to 0V. The Motor Speed slider allows you to control the average voltage in a linear fashion. Note however
that the speed of DC motors does not respond linearly to the voltage applied across it, so the actual motor speed will
not necessarily vary linearly with the position of the Motor Speed slider.
Pulse Time

Pulse Time

Pulse Time
This slider allows you to adjust the amount of time the motor is energized when you click on either the Fwd or Rev
Pulse buttons.
Night Vision

Night Vision

Night Vision
Click the “Night Vision” check box to turn the programs on your computer screen red. The “Motor Speed” and “Pulse
Time” sliders need to each be clicked in order to turn them red. Conversely, when switching “Night Vision” off both
sliders need to be clicked in order to return them to “regular” mode.
Set Point Tolerance

Set Point Tolerance

Set Point Tolerance
This feature permits setting a ± amount of leeway to visually alert you when you are approaching one of your focus
presets (the box turnes yellow) or at focus (box turnes green). Values may be typed in or scrolled using the buttons.
Poll Time

Poll Time

Poll Time
Poll time is how often in milliseconds Focusmaster samples the readout of the digital indicator when in “Read Continu-
ously” mode. The range is from 200 to 1000 milliseconds (1000mS = 1 second). The quicker the polling speed