HC Series Improper Tool Data Effects

Introduction

It is possible to have a condition where an HC series robot appears to be stuck in a 6004 ESCAPE FROM CLAMPING ERROR(PFL) alarm condition that, while it appears to be able to be RESET, will re-occur as soon as any robot motion is attempted.

Details

A 6004 ESCAPE FROM CLAMPING ERROR(PFL) alarm occurs on CPU1 and CPU2.  

This will cause the robot to also enter into Category 2 STOP STATE MONITORING and illuminate the white RESUME button on the B-axis.  Selecting the RESET button on the pendant will clear this ALARM message.  And pressing the RESUME button on the B-axis will cause the light to go off, indicating that all is well.  However, any attempt to move the robot will immediately result in an ERROR 0961 that states “This control group is running [1].”  CANCELing this ERROR will clear the error window and allow you to see that the original ALARM 6004 ESCAPE FROM CLAMPING ERROR(PFL) situation has re-occurred.

Cause

This situation can be caused by trying to move the robot after an incorrect Tool is selected which results in an External Force value that exceeds a VALID EXTERNAL FORCE FILE once that incorrect Tool Data become active in the controller.

In order to recreate this situation the following setup was used:

1. An EXTERNAL FORCE FILE limited to 100N (same as shipped by YAI) is VALID.
2. The robot is initially using Tool 1 which has a correct Mass value set to 1kg.  This Tool is used to calibrate the robot Torque Sensor Origin Position which then results in Force values close to zero when viewed in the Force Monitor.
3. Tool 10 is set to an incorrect Mass value of 12kg.
4. Tool 10 is selected for use.  This causes Tool 10 to be displayed in the upper right corner on the Status Display line.  However, the data in the Tool 10 file is NOT yet being used by the controller due to Tool Change Muting.  The data in Tool 10 will only become active in the controller once the TCP has been moved >5mm.
5. The robot TCP is now moved >5mm and the 6004 ALARM occurs and the above described situation is realized.

Analysis of the Situation

When the robot TCP is moved >5mm the robot controller switches from using the correct Tool 1 1kg Mass value to the incorrect Tool 10 12kg Mass value.  This results in a perceived External Force file of (12kg – 1kg = 11kg) ~110N.  This is in violation of the VALID 100N EXTERNAL FORCE FILE limit.

Resetting this Alarm and pressing the RESUME switch on the B-axis can be performed, but since the EXTERNAL FORCE FILE limit of 100N is still being violated, any attempt to move the robot will result in ERROR 0961 and the re-occurance of the ALARM 6004.

Recovery Method

Switching from the incorrect Tool 10 to the correct Tool 1 does NOT recover from this condition.  This is because the correct Mass value of 1kg that is entered in Tool 1 will NOT be used by the controller until the TCP is moved >5mm.

Recovery can performed by changing one of three of the conflicting conditions.  The change can be a temporary one and unchanged once a fully recovered condition is achieved.

1. Disable PFL mode.
2. Edit the incorrect Tool Data Mass (Tool 10) to be a correct value of 1kg.
3. Edit the violated EXTERNAL FORCE FILE limit(s) to allow the measured Force of 110 N without violation.