Common Errors with the Fanuc Robot

When working with the Fanuc robot, several errors occur frequently. Below are some of the most common errors and how to resolve them.

Error 1: SRVO-003 Deadman switch released / SRVO-002 (Location) E-stop
The most common errors are related to the Deadman switch not being released properly or the emergency stop being pressed. This error message causes the robot to stop abruptly, which can be undesirable as the stop is often forceful and could potentially damage the robot. If it is not strictly necessary, it is better to bring the robot to a stop in another way. However, this can be easily resolved by pressing the reset button.

Error 2: MOTN-(Number) In singularity
The robot has 6 axes, and the movements of these axes must be precisely coordinated to perform the desired tasks. However, if axes 4 and 6 align, there is a risk that the robot may become stuck in a singularity. This can happen both when manually jogging the robot and when the robot is moving automatically from point to point.

A singularity occurs when two or more axes of the robot align. In this situation, the robot’s end effector (e.g., the gripper) can no longer move freely because the robot loses its degrees of freedom. When this happens, the robot can no longer be controlled in multiple directions, leading to it getting stuck or making uncontrollable movements. This can affect the robot’s force and precision. Singularity typically occurs when the robot is in extreme angles or positions, where the movement range of the axes is severely limited.

To prevent getting stuck in singularity, the program can be modified by adding additional waypoints at specific movements. These waypoints ensure that the robot does not inadvertently reach a position where the axes align and cause it to get stuck. If the robot does get stuck in singularity, it can be easily resolved by switching the robot to joint frame mode and moving each axis out of singularity. This allows the robot to be repositioned back into a workable configuration.

It’s important to note that when the robot is close to singularity, other issues may arise. A common issue is that axes 4 and 6 may rotate excessively, which could cause them to reach their limits. This can not only result in damage to the robot but also lead to inaccuracies in movement. Therefore, it is crucial to ensure that the axes remain around 0 degrees and do not reach positions where they might hit their limits.

Error 3: SRVO-230 Chain (0 or 1) ((+24V) or (-24V)) abnormal
A less frequent error is the “SRVO-230 Chain (0 or 1) ((+24V) or (-24V)) abnormal”. This error typically occurs when the deadmanswitch is not properly engaged.
To resolve this error, follow these steps:

  • Go to the menu:
    • Select 0 Next,
    • Choose 6 System,
    • Press F1 Type,
    • Go to 6 Config,
    • Scroll up until you see the option “Reset CHAIN FAILURE detection: FALSE”.