SRVO-026

Identify Which Axis Triggered the Alarm

Press ALARM on the teach pendant, select the SRVO-026 alarm, and press HELP or DETAIL (F5). The alarm detail screen will show which specific axis number exceeded its limit. Note this axis for further investigation.

The axis number shown corresponds to the physical joint (J1-J6 on 6-axis robots). J4, J5, and J6 wrist axes are common culprits due to their lower mass and higher velocity capabilities being pushed by certain orientations.

Check Current Override Setting

On the teach pendant main screen, verify the current OVERRIDE value (typically displayed as a percentage 0-100%). If override is set above 80%, reduce it incrementally to 70%, 60%, or 50% and re-run the motion to see if the alarm clears.

Production environments often run at 100% override by default. This alarm indicates you've hit a physical limitation - reducing override is the quickest fix without program modification.

Review Programmed Motion Speed

Edit the motion instruction that triggered the alarm (typically visible in the program position before the alarm). For joint moves (J), check the speed value (e.g., J P[1] 50% FINE). For linear moves (L), check both speed and CNT value (e.g., L P[2] 2000mm/sec CNT100). Reduce the speed value by 20-30% and test.

Reducing speed may impact cycle time. Document original values before making changes so production requirements can be reviewed.

Optimize Path with Appropriate CNT Values

If using linear (L) or circular (C) moves with CNT (corner rounding) values, the alarm often occurs at the blend point. Navigate to MENU > SETUP > Host Comm > Display motion path (if available) or single-step through the program. Reduce CNT values from CNT100 to CNT50 or CNT25 to create smoother, less aggressive corner transitions.

CNT100 creates very tight corners that force wrist axes to rapidly reorient. CNT values between 25-75 often provide the best balance between speed and joint velocity demands.

Consider Path Modification for Efficiency

If speed reduction is unacceptable for cycle time, review the overall path. Add intermediate points to create smoother transitions, or modify approach/depart points to avoid extreme joint configurations. Use the teach pendant's position display (MENU > NEXT > Position) to view joint angles at problematic points.

Positions where one joint is near its mechanical limit (0° or 360° for rotational axes) often create speed spikes. Moving the position 20-30mm in Cartesian space can dramatically change joint configuration and reduce velocity demands.

Verify Current Payload Setting

Navigate to MENU > SETUP > Payload on the teach pendant. Check which payload number is currently active (typically displayed as PAYLOAD[1] through PAYLOAD[8]). Note the weight (kg), X, Y, Z center of gravity offsets (mm), and inertia values displayed.

Incorrect payload settings can cause not only speed alarms but also path accuracy issues and potential mechanical damage over time.

Measure or Calculate Actual Payload

Physically weigh the end effector and any part being handled. Measure or calculate the center of gravity from the mounting flange. Navigate to MENU > SETUP > Payload, select the appropriate payload number, and enter the correct Weight and X, Y, Z CoG values. Press ENTER after each value.

For complex end effectors, use the Payload Identification feature: MENU > SETUP > Payload ID. Move the robot through several orientations with the load, and the controller will calculate payload parameters automatically.

Check System Variable $PAYLOADS

For confirmation, navigate to MENU > DATA > System Variables. Type '$PAYLOADS' and press ENTER. This displays all configured payload sets. Verify the active payload matches your physical configuration and the schedule value ($PAYLOAD_ID) points to the correct payload number.

Many programs switch payloads mid-cycle using payload scheduling. Search your TP program for 'PAYLOAD[' commands to ensure the correct payload is active during the motion that triggers the alarm.

Test Motion with Default Payload

Temporarily set PAYLOAD[1] to zero values (0 kg weight, 0,0,0 CoG) and retest the problematic motion at reduced speed (50% override). If the alarm disappears, payload configuration was contributing to the issue. Gradually increase to correct payload values while monitoring for the alarm's return.

If the alarm persists even with zero payload, the issue is purely geometric/speed-related and not payload-dependent.

Identify Robot Position and Configuration

When the alarm occurs, immediately press and hold the SHIFT button and press POSN (Position) on the teach pendant to capture the current position data. Note the joint angles displayed (J1-J6) and the configuration flags (F U T, representing flip, up/down, turn). Extreme joint angles often correlate with speed limit issues.

Wrist axes (J4, J5, J6) have the highest speeds but lowest mechanical reduction. They're most likely to hit limits. If J5 is near ±90° or J4/J6 are rotating through ±180°, these are high-risk positions for speed limits.