Structure and functions 
NK823x hardware
4 
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Building Technologies   
A6V10062437_a_en
Fire Safety & Security Products    30.06.2013
 
NK823x Ethernet port unit (NK8235 in this example) 
4.2.1  Front panel 
The front panel houses 9 LED’s. 
Left Side LED’s 
The five LED’s on the left side are, from top to bottom: 
Power (LED green) 
Power (hardware – controlled). 
Vital functions (LED green) 
Software vitality: 
 
Blinking (1 flash)
: core software running. 
 
Blinking (2 flash)
: core software running and logging function active. 
Tamper (LED bicolour) 
Unit tamper: 
 
Red
 means tamper alarm (hardware controlled). 
 
Green
 means tamper disabled (from management station). 
Download (LED red) 
Network diagnostics: 
 
Off
: status OK. 
 
Blinking (1 flash)
: missing identification from NS8xxx. 
 
Blinking (2 flashes)
: not used. 
 
Blinking (3 flashes)
: FTP channel open (default mode; for switch settings see 
Internal DIP Switches
. 
 
On
: critical/hardware fault. 
Diagnostics (LED yellow) 
Internal interface diagnostics: 
 
Off
: status OK. 
 
Blinking (fast)
: booting operating system after restart. 
 
Blinking (1 flash)
: missing or insufficient license.