Which of the following is a common fixed post duty?

Monitoring cameras is a common fixed post duty because it involves remaining in a designated location to oversee security feeds and watch for any suspicious activity or security breaches. This duty typically requires the guard to stay alert and focused on multiple camera views to ensure the safety and security of the premises.

In a fixed post role, the primary objective is often to maintain a vigilant, watchful presence in a specific area, which aligns perfectly with the responsibilities of monitoring surveillance cameras. This task allows the security officer to provide immediate responses to any incidents observed on the monitors, making it a proactive measure in maintaining safety and responding to potential threats.

Other options, such as patrolling clocked rounds and patrolling in a vehicle, are generally categorized as patrol duties rather than fixed post responsibilities. While these are also important for security operations, they involve movement and may not focus on a single stationary position. Approaching trespassers involves taking action in response to a situation, but it is typically not a duty associated with fixed posts, which concentrate on observation and monitoring from a specific location.