What is initiated by the arc switch prior to cartridge deployment?

The arc switch is a critical component of the Taser 7, and its function prior to cartridge deployment is to create a warning arc. This warning arc serves multiple purposes: it alerts both the operator and the subject that the device is active and prepared to deliver a discharge. The visible display of electricity can serve as a deterrent, which may help defuse a potentially volatile situation without the need for full deployment of the device.

In contrast, the other options describe functions that are not initiated by the arc switch prior to cartridge deployment. A discharge of energy occurs only after the cartridge is actually fired, while a safety check and a diagnostic test involve internal mechanisms that confirm the device is operational, but do not involve the creation of an arc. The warning arc is specifically meant to indicate readiness and to potentially discourage aggression, making it a key feature in the operation of the Taser 7.