Description of parts

Power On

The device takes power from AZ GTi mount. There is no power switch. Connecting to the mount and power mount on, the device will turn on sequencially.
It blink slowly twice when device started normally.
It keep rapidly flashing when Error happend, such as communication failed with the mount.

LED light will be leaked from the side of the rotally switch.

Connect to an Autoguider

Connect ST4 RJ11 cable on ST4 port.

1: No Connection
2: Gnd
3: RA+
4: DEC+
5: DEC-
6: RA-

Guide Speed Setting

Set guide speed by the rotary switch.
Guide Speed is set only when power the device on. If you want to change guide speed, disconnect from the mount, set new value for the rotary switch, then connecto to the mount again.

※Setting Rotary Switch to “0” , it does not set sidereal speed when idle. And GuideSpeed is fixed to x1.5 speed of sidereal speed. This mode might be used for Alt-Az mode settings.

DEC Backlash Compressor

When DEC axis move the opposite direction from previous movement, “DEC Backlash Compressor” makes pre-movement to consume backlash period rapidly, then compress delay time by backlash.

The Concept of Backlash
The concept of DEC Backlash Compressor
Little under compression is appropriate.
Consuming most of backlash, and leave little dilay for mild gear contact.

How to configure DEC backlash compression level

You can set how much arc-second to skip. Setting the roraty switch to “8” and power it on, It become backlash compressor setting mode. You can adjust from 42.5 to 77.5 (arc-second).

In this mode, DEC axis moves exact configured angle, and move 5 times in each direction. (You can not run autoguide with this mode)

Between each 5-times-movement, new setting is saved to memory. Please wait for next 5-times-movement to make sure that new value is saved.

How to confirm DEC Backlash level visually

Point telescope to far and fixed object with large magnification.
・Recommend to set as alt-az mount for easiler adjustment.
・Recommend to do in daytime.

In setting mode, DEC axis move 5 times each for direction. You can hear motor sound 5 times as it moves

Appropriate adjustment: You can hear motor movement 5 times, but you only see motor movement 4 times. First time movement is used to consume backlash then does not make any movement.

Appripriate Adjustment

・Over adjustment (Not good) : You hear motor sound 5 times, and see motor movement also for 5 times. This means, backlash adjustment moves more than backlash, and cause over reacting. In this case, please decrease value.

Also, if you see DEC+ and DEC- adjustoment one after another, there is highly possibility of over adjustment. Please decrease value for that case.


・Under Adjustment: You hear motor sound 5 times, and you only see motor movement 3 times or less.

※Once adjustment is done, power the device off BEFORE changing rotary switch. Then Set rotary switch to desired guide-speed, and turn it on.


LED light is inside and it slightly leak from both side of rotary switch.

Power on normally: Blink slowly like ” – — – –”

Error: Flashing fast  

While guiding, it lights up while at least one signal is on

When backlash adjustment mode: Lights up along with 5-times-movement


Please do not run autoguide, nor attach the device to the mount WHILE you are operating mount like ALIGNMENT, GoToMovement, Manual Movement from other controller like SyncScanApp. Because this device use SkyWatcher Motor Control protocol, and so is SyncScanApp. Giving command to the mount from different controller at the same time may cause conflict and may cause mount stop and you need to restart the mount to recover it.

Please make sure that rotation of RA axis cause this device or connected ST4 cable interfere with tripod, or any of your equipments.

Do not use this device on other mounts except SkyWatcher™ AZ GTi/GTe.

This device can be used in equatorial mode only.

SkyWatcher™ warned that AZ GTi/GTe is not for astro photograpy, and not guarantee performances for photo usage. Therefore, this device does not guarantee the result of photograph, either