Troubleshooting the CTE 6-Axis Arm – VEX Library

If your CTE 6-Axis Robotic Arm is not functioning as expected, there are several things you can try to help resolve the issue. Follow the guidance in this article to help get your 6-Axis Arm up and running.

Check your cables

The first step to troubleshooting your CTE 6-Axis Arm is to ensure that it is properly powered and connected.

The back of the 6-Axis Arm, showing the three ports on the base. The power cable is plugged into the right side port.

Check that the power cable is inserted fully into the back of the 6-Axis Arm, and plugged into a power source. View this article to learn more about Powering the 6-Axis Arm.

The back of the 6-Axis Arm showing the USB-C cable plugged into the left side port, the center Smart Port is empty, and the power cable is plugged into the far right port. A green indicator light glows to show connection.

Be sure that the USB-C cable is inserted fully into the USB-C port on the back of the 6-Axis Arm and connected to your computer. Once powered and connected to the computer, the green indicator light will show. View this article to learn more about connecting the 6-Axis Arm directly to your computer.

Note: After initial connection, if the USB-C cable is disconnected and the power cable remains plugged in, the green light may continue to show.

Check your VEXcode connections

Once you are sure your 6-Axis Arm is powered and connected to your device, the next step is to ensure your VEXcode settings are correct.

Direct Connection

The VEXcode interface zoomed in on the upper left corner, showing the CTE logo at the far left of the Toolbar.

If directly connecting the 6-Axis Arm to VEXcode EXP, ensure that you have followed the steps in the device specific article in this section. You should see the CTE logo in the upper left corner of VEXcode when using direct connection, as shown here.

The upper right side of the VEXcode Toolbar, with the 6-Axis Arm icon shown in orange, highlighted with a red box, indicating the firmware is out of date.

Be sure the 6-Axis Arm's firmware is up to date. If the 6-Axis Arm icon in the VEXcode Toolbar shows orange, the firmware needs to be updated. View the articles below to learn more about updating the firmware on the 6-Axis Arm:

Connection with the EXP Brain

The back of the base of the 6-Axis Arm showing the Smart Cable connected in the center port. The left and right ports are empty.

When connecting with the EXP Brain, be sure that the USB-C cable and power cord are no longer connected to the 6-Axis Arm. The 6-Axis Arm should only be connected to the Brain via the Smart Cable.

The VEXcode interface zoomed in on the upper left corner, showing the EXP logo at the far left of the Toolbar.

Be sure that you see the EXP logo in the upper left corner of VEXcode, as shown here. View this article to learn more about creating a New Blocks project in VEXcode EXP.

The Device configuration for the 6-Axis Arm, showing the step of selecting the port. The top dialog box reads Arm 10 and port 10 is selected.

Next, check that the 6-Axis Arm is configured correctly. Be sure that the port selected in the configuration matches the port the 6-Axis Arm is plugged into on your EXP Brain. Read this article for steps on how to configure a 6-Axis Arm in VEXcode EXP.

The upper right side of the VEXcode Toolbar, with the 6-Axis Arm icon shown in orange, highlighted with a red box, indicating the firmware is out of date.

Be sure that the 6-Axis Arm's firmware is up to date. To update firmware, you will need to disconnect the 6-Axis Arm from the Brain, and directly connect it to VEXcode, as described above.

View the articles below to learn more about updating the firmware on the 6-Axis Arm:

Check the 6-Axis Arm with the Teach Pendant

Once you have successfully powered and connected your 6-Axis Arm, and you know that the firmware is up to date, the next step is to directly connect the 6-Axis Arm and use the Teach Pendant to help diagnose the issue. When using the Teach Pendant, be sure that the 6-Axis Arm is not connected to the Brain. The 6-Axis Arm must be directly connected to VEXcode to use the Teach Pendant. View this article to learn more about Accessing the Teach Pendant with the 6-Axis Arm.

Move to Safe Position

The top of the Teach Pendant in VEXcode with the Move to Safe Position button in the upper left corner highlighted in a red box. The status reads Click Move to safe position to continue and the X, Y, Z coordinates are shown in the dashboard.

Select the Move to Safe Position button at the top of the Teach Pendant to see if your 6-Axis Arm can successfully reach the safe position. View this article to learn more about Accessing the Teach Pendant with the 6-Axis Arm.

Jog the Arm

The top of the Teach Pendant in VEXcode is shown with a red box highlighting the 6 Arm jogging buttons below the Dashboard. The buttons are in 2 rows of 3. The top row reads +X, +Y, and +Z. The bottom row reads -X, -y, -z.

Next, use the Arm Jogging buttons to try to move the 6-Axis Arm along each axis. Be sure that the 6-Axis Arm is moving when the button is pressed, and look to see that the X, Y, and Z values in the Dashboard are changing as the 6-Axis Arm moves. Read this article to learn more about jogging with the Teach Pendant.

Teach Pendant Errors

If an error appears in the Teach Pendant Status as you are moving the 6-Axis Arm, there are additional troubleshooting steps you can take to try to resolve the issue.

The top portion of the Teach Pendant showing the Status bar reading an error of Invalid Position Requested, highlighted in a red box.

The Status in the Teach Pendant Dashboard will alert you to errors with your 6-Axis Arm. When there is an error, the Status bar will show red and the error will be displayed. The error will continue to display until it is resolved, and the 6-Axis Arm has successfully moved to a valid or safe position.

Depending on the error reported, there are different steps to take to try to solve the issue. Here are some of most common errors and steps to try to resolve the issue:

Invalid Position Requested - The position you are trying to reach is not within the bounds of the 6-Axis Arm.
- If you are jogging the Arm, you will notice that certain jogging buttons may now be disabled. Try moving the 6-Axis Arm in the opposite direction on the same axis until the error is resolved and all jogging buttons are enabled again.
- If you were moving to a position, the coordinates entered are not within the reachable position for the 6-Axis Arm. Select Move to Safe Position to return the 6-Axis Arm to a safe position, and adjust your coordinates to be within the bounds of the 6-Axis Arm.
- To learn more about the using the Teach Pendant to find the reachable positions of the 6-Axis Arm, view this Lesson in the Introduction to the 6-Axis Arm Course.
An unexpected error occurred while moving to safe position - The 6-Axis Arm encountered an error while trying to move to the safe position.
- Try selecting Move to Safe Position again, to see if it will move successfully after a few moments.
- Try power cycling the 6-Axis Arm by disconnecting the power and USB-C cable from the back of the 6-Axis Arm. Wait about 10 seconds, then plug the cables back in. Close and reopen VEXcode, or refresh the page if using web-based VEXcode. Then reconnect to VEXcode and try to Move to Safe Position again.
Command execution failed due to... - An error occurred and the 6-Axis Arm could not complete the movement.
- Try selecting Move to Safe Position again, to see if it will move successfully after a few moments.
- Try power cycling the 6-Axis Arm by disconnecting the power and USB-C cable from the back of the 6-Axis Arm. Wait about 10 seconds, then plug the cables back in. Close and reopen VEXcode, or refresh the page if using web-based VEXcode. Then reconnect to VEXcode and try to Move to Safe Position again.
Failed to Move to Safe Position: controlled stop enabled - The 6-Axis Arm triggered a controlled stop while trying to move.
- Check to be sure that the 6-Axis Arm did not collide with an obstacle in its path, or that the Controlled Stop button on the Signal Tower was not pressed accidentally. Clear the obstacles and try selecting Move to Safe Position again.
- Try power cycling the 6-Axis Arm by disconnecting the power and USB-C cable from the back of the 6-Axis Arm. Wait about 10 seconds, then plug the cables back in. Close and reopen VEXcode, or refresh the page if using web-based VEXcode. Then reconnect to VEXcode and try to Move to Safe Position again.

Test the Joints if Errors Persist

If the errors continues to persist, you can manually test each of the joints on the 6-Axis Arm, to ensure they are moving as expected, using the Teach Pendant. Be sure the 6-Axis Arm is powered on, directly connected to VEXcode, and not connected to the Brain, to use the Teach Pendant.

The top portion of the Teach Pendant in VEXcode with the Enable Manual Mode button in the upper right corner highlighted in a red box. The status reads Ready, and the X, y, and z coordinates are shown.

Select Enable Manual Mode so that you can safely move the 6-Axis Arm by hand. To learn how to enable Manual Mode, see this article.

The very bottom of the Teach Pendant reads Show Advanced Data with a downward facing triangle indicating what to select to expand and view the Advanced Data.

At the bottom of the Teach Pendant, select Show Advanced Data.

An example of the Advanced Data is shown at the bottom of the Teach Pendant. Data values for the 6-Axis Arm are shown, and the Joint values for J1 through J6 and the Joint Errors rows of the table are highlighted in a red box, indicating what to look for when testing the joints.

Manually move each joint of the 6-Axis Arm individually. As you move each joint, watch that the values for J1 through J5 are changing. (Note: Joint 6 will always report a value of 0.) If all joints move and the values change, try selecting Move to Safe Position again.

If any of the joints do not move or are not showing changing values, send Feedback through VEXcode and contact VEX Support. Be sure to include your contact information when submitting feedback. View this article to learn more about using the Feedback button.

If the Joint Errors show values other than 0, send Feedback through VEXcode and contact VEX Support. Be sure to include your contact information when submitting feedback. View this article to learn more about using the Feedback button.