# Safety Speed

This chapter explains the maximum permitted speed, speed error, emergency-stop deceleration, and soft speed error in the Safety Speed window.

## Before You Begin

Item | What to Check
--- | ---
Device state | Stop motion and disable the drive before changing protection parameters. Make sure the load is supported and the mechanism cannot move unexpectedly when a threshold changes.
Parameter source | Use protection thresholds from project delivery documents, device specifications, or verified field records. Do not copy parameters from an unknown device.
Original-value backup | Click Refresh to read and record the current values before clicking Apply, so you can restore the last verified configuration if a problem occurs.
Applicability | This window alone cannot confirm model, firmware, or hardware applicability. If an item is missing, read-only, or cannot be written, first check the documentation for the current model and the supported firmware range.

High-risk operation: Apply on a safety page writes protection parameters to the controller, and some are persistent. Stop motion, disable the drive, and secure the load before making changes. Do not change protection thresholds while the device is moving or enabled.

## Safety Speed

Item | Description | Recommendations
--- | --- | ---
Max Motor Speed: | In count/s. Limits the permitted maximum speed; a typical reference is 1.2 times the rated speed. | Set according to the permitted mechanical speed and available safety distance, not only the motor capability.
Max Motor Speed Error: | In count/s. Limits the speed following error. | A limit that is too wide may delay fault detection; one that is too narrow may trigger frequently during normal acceleration or deceleration.
Emergency Stop Speed: | In count/s². Controls emergency-stop deceleration; a typical reference is twice the rated speed. | Excessive deceleration may impact the mechanism, while insufficient deceleration may increase stopping distance. Verify it against the available safety distance.
Soft Speed Error: | In count/s. Used for software speed-error protection; the reference documentation does not provide a universal recommended range. | If reading or writing fails, do not apply repeatedly. First confirm support for the current model and firmware.

Use the Safety Speed window to view the current speed and configure speed, speed error, and emergency-stop deceleration.

## High-Risk Operations

Operation | Risk | Recommendation
--- | --- | ---
Adjust the bus-voltage limits | May make overvoltage or undervoltage protection too permissive or too restrictive. | Set according to the drive and power-supply specifications, then monitor the warning state.
Adjust current limits | May affect output capability and overload protection. | Make small adjustments within the device specifications and monitor current and faults.
Adjust torque limits | May affect output capability, holding force, and mechanical safety limits. | Set according to the device specifications and mechanical-safety requirements.
Adjust temperature limits | May change the temperature-protection trip point. | Set according to the device specifications. Do not raise the threshold merely to suppress a warning.
Adjust position limits | May affect travel limits and mechanical safety. | Verify both directions and the limits at low speed over a short travel.
Adjust speed limits or emergency-stop deceleration | May affect stopping distance, impact, and protection triggering. | Verify against the available safety distance and load inertia.
Adjust stall thresholds or force-control limits | May delay stall protection, cause false warnings, or produce abnormal output. | Start with verified parameters and validate under light load before normal operation.

## Troubleshooting

Symptom | Recommended Action
--- | ---
Frequent warnings or stops after applying settings | Restore the last verified parameters. Check whether thresholds are too narrow, the load has changed, or the power supply is abnormal.
Protection does not trigger as expected | Check whether thresholds are too wide and whether the current control mode matches the actual feedback. Confirm that the firmware supports the parameter.
Some items are missing or read-only | Confirm that the current model, hardware version, firmware version, and project delivery documents support this setting.
Read or write fails | Do not apply repeatedly. First verify the connection, device ID, firmware version, project documentation, and current error state.
Position or speed limits do not match motion behavior | Cross-check Motion, Motor Settings, Feedback Settings, Control Mode, and the protection parameters on this page to avoid conflicting settings.