AUDIO  CONTROL  LED/SWITCH  MODULE 
Control  of  audio  functions  are  performed  by  operating  switches  on  LED/Switch  modules  which  are  mounted  on  the 
NDU  Front  Panel.  The  functions  and  quantity  of  the  LED/Switch  modules  depend  on  the  desired  options  and  the 
number  of  channels  in the  audio  system.  Labels  are  inserted  into  the  slots  on  the  LED/Switch  modules  to  identify 
the  function  of  each  switch  and  LED. 
Standard  switches  on  the  Audio  Control  LED/Switch  Module  for  Single  and  Triple  Channel  operations  are  three 
position,  momentary  switches.  Dual  Channel  systems  normally  use  three-position  maintained  switches.  An  optional 
Audio  Control  LED/Switch  Module  with  three-position  momentary  switches  is  available  for  Dual  Channel  audio 
systems. 
VOICE MESSAGES 
The  NDU  audio  system  is  available  with  Voice  Messages.  These  messages  are  selected  at  order  entry  to  meet 
customer  requirements.  The  messages  may  contain  various  tones  along  with  specified  phrases  which  instruct 
building  occupants  to  behave  in a manner  appropriate  to  the  abnormal  conditions.  An  example  of the  Drill  Message 
follows: 
“This  is  a drill.  This  is a drill.  This  is  a drill.  All  occupants  report  to  the  nearest  stairway  exit 
dloor, 
and await  further  orders.  Do not  enter  stairway.” 
NOTE: 
The  above  Drill  Message  will  play  three  times.  It may  be followed  by another  Voice  Message,  or the  operator 
may  elect  to  use  the  audio  system  microphone  for  additional  announcements. 
VOICE CODED  DIGITS 
Voice  Coded  Digits  (0 through  14)  are  also  available  to  support  audio  messages.  These  are  spoken  numbers  which 
identify  a  location  or  condition  within  the  building.  They  are  normally  used  in conjunction  with  Preambles. 
PREAMBLES 
Preambles  for  Voice  Coded  Messages  are  available  with  the  NDU.  These  Preambles  are  specified  at  order  entry 
and  are  programmed  into  the  system  to  meet  customer  requirements.  An  example  of  a  Preamble  with  Voice  Coded 
digits  is: 
“Dr.  Red,  your  assistance  is  required  in area  Three  - One  -  Four.“ 
Other  examples  of  Preambles  are  as  follows: 
l 
“A  Fire  Emergency  has  been  reported  in area  (voice  coded  digits).” 
l 
“Dr.  Firestone,  please  dial  (voice  coded  digits).” 
l 
“An  emergency  has  been  reported  in  area  (voice  coded  digits).” 
l 
“Dr.  Blaze,  please  dial  (voice  coded  digits). 
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