These systems consist of one or more digital color cameras and a scalable Digital Video Recorders (DVRs) and Network Video Recorders (NVRs). These devices are usually a desktop or tower PCs sometimes configured with audio channels and VOIP capabilities. These systems are used to monitor critical areas over the network and record all activity or events. They allow for listening-in to whatever is happening in an area and recall the video and audio at a later time. VOIP capability is used so persons in the monitored area can pick up the phone and immediately talk to the central station personnel who are looking-in and listening-in to the situation.
An “Interactive” system is one which allows the monitoring station personnel to not only listen-in but to “talk down” over speakers and actually “intervene” in a robbery or hostage taking by talking to the perpetrator and attempting to diffuse the situation. These systems allow those with authority to look at live video/audio feeds and recordings. The features can be accessed over a network or over the internet by using a web browser. Sometimes these video/audio systems are used in conjunction with PMAC systems.