Structure and functions 
NK823x hardware
4 
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Building Technologies   
A6V10062437_a_en
Fire Safety & Security Products    30.06.2013
4.2.5  LON interface 
The NK823x Ethernet Ports do not have a LON interface and do not support CS6 
Guarto intrusion detection systems (use NK822x instead). 
4.2.6  Onboard I/O 
The NK823x main board is equipped with three digital inputs (X102) and one relay 
output (X101). The input signals can be used individually or combined together for 
power supply supervision application. 
 
X102 onboard inputs. 
Pin  Signal  Circuit 1 
(internal power supply) 
Circuit 2 
(external power supply) 
1  Input 1 (Mains failure) 
2  Input 2 (Battery fault) 
3  Input 3 (Power supply 
fault) 
4  Common 
5  + Val 
6  - Val 
X102
1, 2, 3
4
5
6
4K7
100R
 
X102
1, 2, 3
4
5
6
4K7
100R
 
 
 
 
X101 onboard relay output. 
Pin  Signal  Circuit 
1  Common 
2  NO 
3  NC 
X101
1
2
3
NO
NC
 
 
 
4.2.7  I2C interface: I/O and power supervision 
The I
2
C interface (X111) allows for a direct support of: 
  Up to 4 DF80xx modules in any combination: 
–  Up to 4 DF8020 output modules 
–  Up to 4 DF8040 input modules 
–  Up to 4 DF8045 supervised input modules (NC inputs) 
–  Up to 4 DF8046 supervised input modules (NO inputs) 
–  One DF8090 power supply supervision module 
The module can be installed on the DIN-rail, next to the NK823x unit. 
DF8020 
DF8020 is a module providing 8 relay outputs, NO or NC.