Futurecom PDR8000 Programming Manual page 55

Channel – Access Code Table ASTRO NAC Assignments
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.
2021-11-0
PDR8000® Portable Digital Repeater Programming Guide
8K088X04 R5.00
Page 55 of 98