Futurecom PDR8000, Руководство по программированию, Страница: 51 / 86

Document 8K088X04 R5.01
PDR8000
®
Portable Digital Repeater Programming Guide
2022-08-25 Page 51 of 86
C
HANNEL
–
A
CCESS
C
ODE
T
ABLE
ASTRO NAC A
SSIGNMENTS
In the Channel Configuration the
‘NAC Code Table’
allows the user to configure NAC
Assignment Table associated with that channel.
The Network Access Code or NAC is a feature of Project 25 digital radios that operates similarly
to PL/DPL codes for analog radios. NAC codes minimize co-channel interference and allow
repeater addressing by keeping the receiver squelched unless a signal with a matching NAC
arrives. NACs are programmed as a 3-digit hexadecimal code that is broadcast along with the
digital signal (Voice, Data, or Supplementary Data) being transmitted.
Since the NAC is 3-digit hexadecimal number (12 bits), it gives 4096 possible NACs for
programming.
Three of these NACs have special meaning:
$293 - the default NAC
$F7E - Receiver Monitor; a receiver set for this NAC will unsquelch on any NAC
received
$F7F - Community Repeater; a repeater receiver set for this NAC will allow all incoming
signals to be repeated with the NAC intact.
PDR8000 allows each of its digital-enabled channels to be configured with a desired behavior
for utilizing NACs. These behaviors are captured in
NAC Code Table . Each configured
channel in the PDR8000 can point to one of the configured Access Code Tables. Each Access
Code Table can be used to define NAC operation for a specific channel or may capture
behavior shared by multiple channels.
The Channel-
Access Code Table ASTRO NAC Assignments’ Table excerpt is shown below
with the description of each field in the following table.