MOTN-050

Access system variable display

From the teach pendant: Press MENU > SYSTEM > Variables. Change Type to 'System Variables' using [TYPE]. Navigate to $SPEEDLIMJNT using the search function or scroll through the list.

Press the [FIND] function key and type 'SPEEDLIMJNT' to quickly locate the variable instead of scrolling through hundreds of system variables.

Inspect all joint speed limit values

Check each array element $SPEEDLIMJNT[1] through $SPEEDLIMJNT[n] where n equals the number of robot axes. Record any values that are negative, greater than 100, or appear as asterisks (***) which indicate corrupted data.

Do not modify system variables while the robot is in AUTO mode or while programs are running. Switch to T1 or T2 mode with HOLD engaged.

Reset invalid values to safe defaults

For each invalid entry, position cursor on the value and press ENTER. Set to 0 to disable joint speed limiting for that axis, or set to a valid percentage (1-100) based on application requirements. Typical default is 0 for all joints unless specific speed limiting is required.

If you're unsure of the correct values, set all joints to 0 initially to clear the alarm, then implement specific joint speed limits only if your application safety assessment requires them.

Cycle power and verify alarm clearance

After correcting all values, perform a controlled power cycle: MENU > SYSTEM > Master/Cal > [F1 COLD]. Alternatively, perform a complete controller reboot. Verify MOTN-050 does not reappear during startup.

COLD start will reset the program pointer to line 1 of all programs. Ensure robot is in a safe position before cycling power.

Verify controller and software version compatibility

Press MENU > NEXT > STATUS > Version ID. Record the controller model and software version. Compare against the backup source or software update documentation to identify version mismatches. Check for HandlingTool, R-30iA, R-30iB, or R-30iB Plus designations.

If you recently restored a backup from a different robot model (e.g., M-710iC backup to M-20iA), speed monitoring variables are often incompatible and require manual reconfiguration.

Check for image backup availability

Navigate to MENU > FILE > Backup. Check if a pre-update or pre-restore image exists with date stamp before the issue occurred. If available, note the file name for potential restoration if variable correction fails.

Restoring a full image backup will overwrite all current programs, position registers, and system variables. Only use as a last resort after documenting current settings.

Reset speed monitoring variables to default state

Access MENU > SYSTEM > Variables > $SPEEDLIMJNT. Set all array elements [1] through [n] to 0. Additionally check related variable $SPEEDLIM_DETECT (if present) and ensure it's set to FALSE or 0. These defaults disable joint-specific speed limiting.

Create a text file backup of system variables before modifications: MENU > FILE > File > select SYSVAR, press BACKUP to CF card or USB for easy restoration if needed.

Verify motion supervision parameters

Check MENU > SETUP > Host Comm > MOTION_MONITOR settings. Verify motion supervision is configured correctly for your controller version. For most applications, standard factory defaults are appropriate unless specific safety monitoring is required.

After software updates to R-30iB Plus, motion monitoring parameters often need reinitialization. Consult FANUC document MAROTKPE01071E (Motion Supervision Function) for version-specific parameter tables.

Review recent system variable modifications

Check MENU > ALARM > ALARM LOG (press F1 HIST). Review timestamps for when MOTN-050 first appeared and correlate with maintenance activities. Check if alarm coincides with programming changes, safety circuit modifications, or speed override adjustments.

The alarm log shows exact date/time stamps. Cross-reference this with maintenance logs or shift change times to identify who made recent system variable changes.

Check for conflicting speed override systems

Verify MENU > SETUP > Speeds > Override settings. Check if Software Servo (SOV) limits are enabled. Navigate to MENU > SYSTEM > Variables and check $MCR.$SPD_OVR and $MCR_GRP[1].$SPDOVR for conflicting speed caps. Also verify $FAST_SPEED and $COLL_DETECT speed parameters.

Do not set $SPEEDLIMJNT values lower than programmed speed override percentages or Software Servo limits. This creates conflicting motion supervision that may cause erratic alarm behavior.

Verify DCS/Safety PLC integration compatibility

If a DCS (Dual Check Safety) or safety PLC system is installed, check MENU > SETUP > DCS Setup for speed monitoring zones. Ensure $SPEEDLIMJNT is not conflicting with safety-rated speed monitoring. Review I/O signals for safe reduced speed (SRS) or safe limited speed (SLS) activation.

DCS-equipped systems manage their own speed monitoring through certified safety logic. In these cases, $SPEEDLIMJNT should typically remain at 0 (disabled) to avoid conflicts with safety-rated supervision.