ASCOM Installation

The latest version of ASICAP has native support for the EAF. Other software packages will require the use of an ASCOM driver.

EAF ASCOM drivers can be found on the ZWO website:

ZWO ASCOM driver

Download and install support for EAF, then launch the EAF dashboard from within your astronomy software.



Introduction of ASCOM driver interface


Note: If you do not have EAF temperature sensor, you can use the inner temperature sensor to detect.


Connecting EAF to your Astronomy Software

There are many kinds of imaging software. We have listed the setting steps of EAF in the mainstream software, so that you can set the EAF in the software more quickly.



1.Open the focuser control panel.

ASICAMP_setting_12. choose the focuser that you connected.

ASICAMP_setting_23. Set suitable settings for your EAF.




1. On the ASIAIR main screen find the icon for the EAF.

ASIAIR_EAF_setting_12. Click the icon and enter the EAF settings page.

ASIAIR_EAF_setting_23.EAF Advanced Settings.




1.Open Sharpcap settings.


2.Choose ZWO focuser.




1.Open the focuser panel in settings menu.


2.Check ”Use ASCOM Focuser”

FireCapture_EAF_setting_23. Choose ZWO Focuser in ASCOM panel.



Sequence Generator Pro



Maxim DL Pro

1. Open “Observatory panel”, in “Focuser 1” option, click “Choose…”.

MaximDLPro_EAF_setting-12. Choose ZWO Focuser in ASCOM panel.



The SkyX

1.Open “Telescope” menu, and select “Telescope Setup”


2.Select “Focuser Setup”

SkyX_EAF_setting_23. select ASCOM Focuser

SkyX_EAF_setting_34. Setup the settings of ASCOM focuser.


5.Choose ZWO Focuser



Additional Installation Information

There is significant torque from the EAF stepper motor. We recommended setting the 0 position and the maximum number of steps as a first step to prevent possible damage to the focuser.

For the standard bracket installation:

The 0 position is recommended to be set to the position when the focuser is fully retracted.

The maximum number of steps is recommended to be set to a limit position less than or equal to the full focuser stroke.

For the curved saddle installation:

The 0 position is recommended to be set near the focus of the focus of the focus holder.

The maximum number of steps is recommended to be set to a limit position less than or equal to the focus seat stroke.


It has to be powered by 12V DC 0.5A and up.


17 Responses to EAF Software Configuration
  1. Avatar

    I have the ZWO-EAF-5V focuser and I feed it at 5VDC with the USB port.
    Can I power it at 12VDC?
    What is the maximum power limit in VDC?


  2. Avatar

    I have 2 EAFs that control different telescopes very successfully, as long as only one EAF is plugged in at a time. I can not select, as I can with my different ZWO cameras. I don’t need them to run at the same time, but I would like choose either one depending on the telescope I want to use for the night, without changing cables. Am I not doing something correctly? Now matter how I try to select a different EAF, it always reverts to the same focuser.



  3. Avatar

    It is available for iMac ?


  4. Avatar

    I use EAF with MaxIm DL Pro 6.
    The ASCOM driver interface does not have a window for entering coefficients for temperature compensation.
    The MaxIm DL Pro side has a check button called “Temp. Tracking”, but is it not possible to perform temperature compensation operation with EAF?


  5. Avatar

    I am having trouble achieving full focus travel using ASIStudio.
    I have mounted the EAF to my Celestron c9.25 focuser using a bracket that directly connects the motor to the scope’s focus shaft (1:1 ratio).
    A c9.25’s focuser takes approximately 45 turns from fully in to fully out.
    I have determined that in ASIStudio, 10,000 steps equates to 1 full turn. This means I need to be able to set maximum steps in ASIStudio to a value of 450,000 steps. Unfortunately ASIStudio is limiting me to a maximum of 60,000.
    Please update your software/firmware to allow a higher limit or advise on how I should proceed.
    I suspect the same issue applies when using ASCOM.


    • Avatar

      We will think about it.
      Please set the stroke near the focus or set the 0 position multiple.


    • Avatar

      Hi guys,

      I’m using the EAF on a RASA 8 with the SCT 8-9.25 bracket. Like Jim I cannot use the full travel of the focus knob. I have determined that it’s safely 28 turns from 0 to full travel on the focus knob and one full turn is roughly 5720 steps so the maximum “Max step” value would need to go up to 160,160 (5720 steps x 28 turns = 160,160) on a RASA 8. Please can you consider increasing the Max steps in a future update. Thanks


  6. Avatar

    Regarding to use of two EAF on same computer, I’ll have a configuration with two telescopes controlled by N.I.N.A. software with or without ASCOM. I know that I can use two N.I.N.A. instances at the same time, I can use one profile with 1st equipment e a second profile with another including telescope, cameras, guiding, focuser etc. Today I have one EAF for the first telescope and a Seletek focuser on another, its working ok, but I want to replace seletek with a second EAF. It’s possible work with two EAF on same computer without ID’s conflict, maybe with ASCOM? Thanks.


  7. Avatar

    I hope all is fine with you. thanks for this great and nice hardware from ZWO
    please confirm : do i understand correctly that we can use more than 1 EAF unit from the ASICAP software? is it possible to choose the EAF unit for main scope and guide scope in the asicap software and to focus first guide scope and later main scope ?
    thank you for your appreciated reply.
    best regards




Leave a Reply