What does pulling a box in Law Enforcement used to mean?

Question

As an old timer I would do it every 30 minutes or they would come looking for me.

Answer 1

Years ago, there were no portable radios, and not all cops had a car. Many had to walk a beat.

There were call boxes on the streets to summon police. The officers walking the beat were required to call in on a regular basis to let dispatch know they were OK. If you didn't call, a sector car came looking for you.

Answer 2

Something to do with messing with the tattler boxes in the cars?