COMPRO NC420, User Manual, Page: 13 / 80

2-7
Chapter 2: Product Overview
NC450
NC420 NC450
NC420
Digital I/O Connector Block
Digital I/O Connector Block
The I/O connector on the back of the camera provides a central interface between your home security system
and various output devices.
The digital inputs are normally used with security sensors, e.g. passive infrared sensors (PIR), smoke detectors,
door/window sensors, etc. They work by detecting a change in the state of open and closed circuit. You can
check the status of the circuit in [Setup] > [Event Setup] > [I/O Status].
The output port is normally used to trigger external audio or visual indicators, e.g. sirens or strobe lights, etc.
1 2 3 4 5 6 7
Pin Function Specifications Note
1 RS-485 (D +)
N/A N/A
2 RS-485 (D –)
3 Digital Output Port (NC )
+ M a x 2 4 V D C , 1 A o r
Max 125VAC, 1A
Yo u c a n o n l y u s e e i t h e r
the Normally Open (NO) or
Normally Closed (NC) at a
given time.
4 Digital Output Port (COM)
5 Digital Output Port (NO)
6 Digital Input Port (IN –)
Max 5VDC, 60mA Floating, TTL
7 Digital Input Port (IN +)
Table 2-2. Buttons in recording history
Figure 2-6. Digital IO wiring