Digital inputs and outputs (I/O)
A unique feature of network video products is their integrated digital input and output ports, which enable connection to external devices, such as doorbells, detectors (e.g. smoke, movement, sound, temperature and humidity sensors), lights (including infrared lamps), switches and alarm relays, and which are manageable over the network either from a remote PC or automatically using the camera's built-in logic. The I/Os can be used to eliminate unnecessary transfers of video; that is, unless sensors connected to the network camera or video server are triggered, no video is sent over a network.
When input and output mechanisms are triggered, you can manually or automatically request -- through the Axis network video product or an video management software -- that certain actions be performed over the network as well as through output ports. For instance, images saved from before, during and after an event (called pre- and post-alarm image buffering) can be immediately transferred over the network to specified destinations for recording and storage. At the same time, alerts to specific individuals via e-mail or SMS to a mobile telephone can be sent, and connected external devices such as lights, alarms and doors can be activated.
