概述

What is Digital Input?
Digital Input or DI is the pair of pins in the IP camera’s terminal block through which it is possible to connect an external device (a switch or some kind of sensor) with the camera, allowing the external device to notify the camera about an activity in camera site. For example, it is possible to connect a “panic button” with the camera, and when the button is pressed then the alarm signal is sent through the camera all the way to the control center. You can think of the devices that are connected to DI as the triggers of events.

What is Digital Output?
Digital Output or DO is the pair of pins in the camera’s terminal block through which to connect an external device with the camera. That external device can be activated by the camera upon an event inside the camera or by the command from the control center. For example, an alarm siren is a typical device that can be connected to camera’s Digital Output. You can think of the devices that are connected to DO as the responders to events.

Digital Input/Output versus Alarm Input/Output
Since Digital Input and Digital output are most often seen as the applications for alarm system, therefore sometimes the expressions Alarm Input and Alarm Output are used respectively in order to emphasize their alarm-related function. However, sometimes there may be DI and DO based applications that have nothing to do with alarm system and are merely functions of convenience that take a good use of IP-network with the help of camera’s DI and DO ports.

Therefore ACTi uses the general terms “Digital Input” and “Digital Output” rather than alarm input and alarm output.

The Benefits of DI and DO
The main benefit of using camera’s Digital Input is to save cabling effort between the trigger (for example a panic button) and the control site – using the camera’s Ethernet cable, the alarm event can be sent to the control center over the IP-network.

Furthermore it is possible to set the camera to respond to the event instantly without waiting for the command from the control center. For example, when a panic button is pressed then the PTZ camera that was originally pointed elsewhere will instantly turn itself towards the area where the button was pressed.

The benefits of camera’s Digital Output are quite similar. In addition to saving the cabling effort, it is even possible to give instant commands from the camera to external device. For example, if the camera detects a motion either by video motion or passive infrared (PIR) sensor, then the camera can turn on the lights in the room that are connected to DO, so the moving object will be nicely exposed with proper lighting.

应用

Applications of Digital Input
There are countless possibilities of applying external devices to ACTi cameras through DI terminal block. The examples below illustrate several practical usages of DI. The following DI devices are used in those examples:

• Panic Button
• Emergency Button
• Smoke Detector
• Passive Infrared Sensor
• Magnetic Contacts of Windows and Doors
• Glass Break Detector

Applications of Digital Output There are countless possibilities for digital output applications as well. Almost any external device you want to be activated upon the alarm can be connected to DO terminal block of the camera. The examples below cover several applications that are most often used in security solutions. For simplicity, all the examples below use the video as the trigger for DO actions.

• Lights
• Alarm Siren
• Gate Control
• Magnetic Locks

解决方案

ACTi's NVR 3 and CMS 2 are designed to trigger or respond to the DI/DO events for every ACTi camera that supports DI/DO interface. For example, when the glass break detector sends the signal to the NVR via camera's Digital Input interface, then the NVR can activate the alarm system immediately.