When running three shorts on the communicating buzzer is a signal to:

The signal of three shorts on the communicating buzzer indicates that movement must be stopped at the next station. This is a standard communication method used to convey important operational messages to the crew. When this specific signal is used, it serves as a directive to ensure that the train stops safely and efficiently at the upcoming station, allowing for safe boarding and alighting of passengers.

Understanding the importance of this signal is critical for maintaining safety and compliance with operational protocols in rail transport. It reflects the structured communication that is essential in the train operating environment, ensuring that all crew members are informed and prepared to execute the necessary actions regarding train movements and stops at stations.