What is the acceptable position of the ATC mode switch when leaving the cab?

The acceptable position of the Automatic Train Control (ATC) mode switch when leaving the cab is typically in the "MCS" (Manual Control Station) position. This ensures that the train is in a state that permits safe operation without automatic controls in place, allowing for manual intervention when necessary.

In the MCS position, the train is prepared for controlled movements by personnel, reducing the risk of unintended operations that could occur if the ATC were active while personnel are not present in the cab. This is crucial for safety procedures, as it helps ensure that the system does not inadvertently take control of operations at inappropriate times.

Understanding the roles of the other positions, such as ATC, BY-PASS, and SAFE, is essential in familiarizing oneself with the system's intended operations. However, the MCS is specifically designated for scenarios where human control is necessary, making it the safest position when leaving the cab.