PLC / Drives, Motion & Axis Diagnostics
Keep safe-torque-off status separate from electrical isolation and machine readiness
A drive's STO state relates to its specified safety function, not every electrical or mechanical hazard around the machine.
Environment and inputs: Industrial PLC / automation guidance · Verify the exact controller, module, firmware, engineering tool and machine documentation. Linked vendor examples apply to their stated products and library versions; observation, state changes and physical work require distinct authorization.
Observe and record
Review only the approved safety diagnostics, drive status and machine documentation with the responsible safety and controls owners.
Interpret the evidence
A standard PLC status bit does not validate the whole safety function. Stored energy, gravity and other motion sources require separate controls.
Resolve and verify
Have qualified personnel investigate the indicated safety-channel or drive issue under the machine's validated safety and energy-isolation procedures.
Machine and data safeguards
Do not bypass STO, bridge safety inputs or treat a software indication as permission to touch power circuits or moving mechanisms.