GTOCP4 Software ** Current Version

If you are searching for previous version P01-14, click on this link.

The software for the Astro-Physics GTOCP4 Servo Control box can be updated to the latest version from this page by following the procedures below. We now offer two methods for updating your control box. Choose the one that is most suited to the connections you typically use.

Ethernet: If you have already established an ethernet connection, this may be the one to choose. This can be either a direct peer-to-peer connection or through a wired local network. WiFi is not currently allowed because it is generally less reliable than cabled Ethernet.

USB/Serial Utility. If you normally connect with a USB cable, USB-to-serial adapter or serial cable, this utility provides a quick and easy way to update to your control box. The utility is a .jar file requires that Java be loaded on your computer. Java files can be used across a variety of platforms including Windows, Mac and Linux. However, the present version may not work with all Mac computers so be sure to have a Windows computer available as a backup or use the Ethernet method.

Download Program Package to Your PC
NOTE: The program package is a zip file located in a protected area of our website. To download the package, you will need the username and password that was provided in the cover letter that came with your mount's original documentation. If you do not have this information, please contact Astro-Physics, either by telephone (see below) or email addressed to support at Please provide us with your mount and/or serial number of your GTOCP4 when you contact us. The .zip file contains the following:

For All Ethernet and USB/Serial Loads:

For Ethernet Load:

For USB/Serial Load:

Click on the link below to start the download process. Enter the username and password when prompted to do so. Save the zip file to a convenient place. If you are using the USB/Serial Utility, you do not need to unzip the file.

VCPx-P02-11 Full Package

Upload Software to Your Control Box

Follow the appropriate instructions for your Ethernet or USB/Serial connection. Here is a link to these PDF documents so that you can download and print them for review before you begin the process.

For Ethernet: Field_CP4_Download-browser.pdf document (included in the Full Package download). Please note that the download instructions for the GTOCP4 and GTOCP5 are the same. The document has not been updated to refer to the GTOCP5 yet.

For USB/Serial Utility: USB/Serial Utility

GTOCP4 Manual
Please compare the current GTOCP4 manual to your present manual to be sure that you have the latest. It is linked here for your convenience and is not required for the software update. This is a PDF document that requires Adobe Acrobat or another PDF reader to view it.

Version History and Bug Fixes
Version History and List of Known Bug Fixes (PDF)


Please click the button to get the latest version of Acrobat Reader.

Copyright © 2020, Astro-Physics, Inc. - All Rights Reserved
This page was last modified: February 5, 2022

Astro-Physics, Inc.
11250 Forest Hills Road, Machesney Park, IL  61115, U.S.A.
Phone: 815-282-1513   Fax: 815-282-9847