After a Robot Cell Stops: What to Include in a Service Handover

A robot cell that has stopped can display a message, but a service request saying only “robot stopped” leaves important questions unanswered. Was an emergency stop activated, did a safeguard interrupt motion, or did the controller report another condition? The people responsible for the cell need a reliable event record before they can assess the situation. This article concerns documentation; it is not a reset or restart procedure.

Use the system's own words

Record the message exactly as displayed, including any code, time and affected device. Identify the robot, controller, application and software version if available. If a person activated an emergency-stop device, record that observation without assuming that it explains every message shown elsewhere in the cell. A stop status and a diagnosis are different pieces of information.

Universal Robots' C283 error-code documentation lists several distinct safety-system messages for the specified software documentation. This illustrates why preserving the complete code matters. Its descriptions apply to the documented system and must not be transferred to another manufacturer or software version without verification.

Record what was happening immediately before the stop

Write down the task, operating mode and location only to the extent they are known. Separate direct observations from reports received later. If someone saw a guard open, heard an unusual sound or pressed a stop button, identify the observation and its time; do not turn a sequence of events into a root-cause claim. Preserve relevant logs and screenshots through the organization's approved process.

For example, a worker might report that a cell stopped while a workpiece was being transferred. The incident record can say that the transfer was in progress and identify the displayed message. Without further evidence it should not claim that the workpiece caused the stop. This is a fictional scenario used to illustrate the distinction between observation and inference.

Identify the wider cell and its interfaces

A robot may be integrated with conveyors, fixtures, tooling or other machinery. Record which parts of the application were affected and which equipment owners need to be contacted. Do not assume that a status on the robot controller describes the state of every connected machine. The service team may require the cell's approved diagrams, configuration and maintenance history.

Universal Robots' pre-use assessment guidance for its e-Series includes checks of connected safety inputs and outputs and system emergency-stop behavior. It illustrates why connected equipment matters alongside the robot arm. The actual site must follow the requirements, risk assessment and procedures applicable to its own equipment and location.

Keep personnel safety and service diagnosis separate

If people may be in danger, follow the site's emergency procedure and contact the responsible personnel or emergency services as appropriate. Do not enter a safeguarded area, bypass an interlock, release a stop or reconnect equipment based on an online article. An emergency stop is not a substitute for the hazardous-energy controls required for a particular maintenance task.

Who may inspect, reset or return the application to service should already be defined by the employer, integrator and equipment documentation. The required checks depend on the system and the incident. A user interface becoming responsive, or an error disappearing, is not by itself evidence that the cause has been identified or that the cell is safe to operate.

Give the service team a structured handover

Include the exact message, time, system identity, task in progress and the name or role of the contact who can answer follow-up questions. State which evidence is available and what remains unknown. If the equipment has been changed recently, list the date and scope of the change without assuming it caused the event. Record any authorized actions already taken and by whom.

Logs and cell diagrams may contain customer information, network details or proprietary production data. Share only the material required by the service provider, through an approved channel. Do not post passwords, keys or access tokens in a support ticket or a public discussion.

Close the record with evidence, not a label

After qualified personnel have reviewed the event, record their findings, the work they actually performed and the result of the checks required by the site's process. If the reason remains unknown, say so. An agreed follow-up may be needed even when production has resumed; the responsible team should decide what evidence and authorization are required.

For related service documentation, see our articles on defining a reproduction boundary and separating loaner and repair records, or browse the robot service section. This guide does not replace the manufacturer's instructions or the site's safety procedures.