SRVO-035

Check current speed override setting

On the teach pendant, observe the OVERRIDE value displayed on the position screen. Press MENU > NEXT > System > Variables > $SCR.$PRIORITY to check programmed speed override. Reduce override to 50-75% and test motion. If alarm clears, the motion is speed-limited.

Even motions programmed at conservative speeds can hit joint limits when override is above 100%. R-30iB allows overrides up to 300% in T1 mode, which frequently causes this alarm.

Review motion instruction speed settings

Navigate to MENU > Select > the program causing the alarm. Find the motion instruction (J, L, C) and check the speed field. For joint moves, speeds above 50-75% of joint max often trigger this alarm. Press ENTER on the motion line and reduce speed value (e.g., change J P[1] 100% to J P[1] 50%).

Joint motions (J) are more likely to hit this limit than linear motions (L) because they move each axis independently at full speed.

Analyze joint velocities during motion

Enable position feedback display: MENU > Next > System > Variables. Monitor $MOR_GRP[1].$ACTUAL_ANG_VEL[axis] for the faulting axis during slow jog. Compare to $MOR_GRP[1].$MAX_JNT_SPD[axis] which shows maximum rated speed. If actual approaches within 95% of max, reduce programmed speed.

Axis 4, 5, and 6 (wrist axes) most commonly trigger this alarm due to their higher rotational speeds and smaller moment arms during TCP path following.

Modify motion path to reduce joint velocity demand

Review the robot path using MENU > Utilities > Controlled Start. Motions requiring large wrist reorientations or positions near singularities demand high joint speeds. Add intermediate waypoints or use CNT (corner rounding) values to smooth the path: L P[1] 2000mm/sec CNT50.

Linear motions through wrist singularities can cause joints 4 and 6 to spike to extreme speeds even when TCP speed is low. Reteach the path to avoid singularities or switch to joint motion for those segments.

Check $SPEEDLIMJNT system variable settings

Navigate to MENU > System > Variables > $SPEEDLIMJNT[GP:1,axis]. This variable sets the maximum joint speed as a percentage (0-100%). If values are below 100%, the joint speed is artificially limited. Note the faulting axis from the alarm detail and verify its limit. Default should be 100% unless application requires limitation.

Modifying $SPEEDLIMJNT requires understanding of application safety requirements. Document original values before changes.

Review joint speed limit parameters

Access MENU > Setup > Frames > Motion > Joint Speed Limits or navigate to Parameters > Group: 1 > Joint Speed Limit. Check parameters that may limit joint speeds globally or per axis. Common parameters include max joint speed scaling factors.

Some applications intentionally set $SPEEDLIMJNT lower for collision avoidance or cycle time consistency. Verify with the application engineer before increasing these values.

Verify DCS safety speed monitoring not active

If DCS (Dual Check Safety) is installed, check MENU > System > Safety > Speed Monitor. Review configured speed zones and current zone status. System variable $SAFETY_SPD.$SPD_ZONE shows active zone. If a restrictive zone is active, either exit the zone or modify zone boundaries via Safety Setup (requires safety password).

DCS safety configuration requires authorized personnel with safety training. Improper changes can create safety hazards and violate risk assessment requirements.

Compare against robot model specifications

Access MENU > Status > Version > Product ID to confirm robot model. Cross-reference with robot manual section 2 (specifications) to verify rated maximum joint speeds for each axis. If $SPEEDLIMJNT or commanded speeds are within spec but alarm persists, a servo tuning issue may exist requiring parameter review.

Keep a copy of the robot datasheet with rated speeds posted near the controller. This allows quick verification during troubleshooting without searching through manuals.

Verify payload configuration accuracy

Navigate to MENU > Setup > Frames > Payload. Check PAYLOAD[UT:1] settings for mass (kg) and center of gravity (X, Y, Z in mm). If payload is underestimated, the controller undercompensates, requiring higher joint speeds to maintain motion. Measure actual tool weight and update values. Use Payload Identification wizard if available: MENU > Setup > Frames > Payload > F2 [DETAIL] > Payload ID.

After changing payload, perform a slow test motion. Watch for smoother acceleration profiles and reduced servo error if payload is now correct. Incorrect payload also causes MOTN-023 and servo alarms.

Check inertia moment settings for large tools

For tools with high rotational inertia, access MENU > Setup > Frames > Payload > F2 [DETAIL] and verify inertia moments (Ixx, Iyy, Izz). Large grippers, welding guns, or rotating tools require accurate inertia values. If unknown, use conservative estimates or calculate from CAD models. Underestimated inertia causes wrist axes (4-6) to demand excessive speed.

Grossly incorrect inertia values can cause instability or oscillation in wrist axes. Make incremental adjustments and test at low speed.