How is guarding a Zone against more than three USER MODELS accomplished?

The method of guarding a Zone against more than three USER MODELS is accomplished using the Tool Change Function. This function is typically designed to manage how tools are changed in the machining process, ensuring that only the specified tools are used within particular operational zones. By controlling the tool selection, the system can prevent the introduction of additional user models beyond the predefined limit, thereby enhancing safety and operational consistency.

This approach leverages the capabilities of the tool change mechanism to create a regulated environment where only authorized user models are permitted to operate, thus ensuring compliance with operational protocols. The Tool Change Function acts as a gatekeeper, making it an effective way to manage and restrict user models within a given zone.

Other options involve different functionalities that do not directly address the management of user models in this specific context. Software permissions, configuring safety locks, and setting user alerts are relevant in broader contexts of system security and operational integrity but do not specifically provide a mechanism for limiting user models in the way the Tool Change Function does.