Codan Radio P25 Training Guide - Manual (Page 33)

P25 RADIO SYSTEMS | TRAINING GUIDE
Chapter 3: P25 Technical Information Page 25
Network Access Code (NAC)
The NID contains the 12 bit NAC fi eld. NAC codes are user programmable and are typically used to
control network access but may also be used to steer repeater functions. NAC codes are used the
same way as an analog CTCSS tone (or DCS code). NAC codes minimize co-channel interference
and allow repeater addressing by keeping the receiver squelched unless a signal with a matching NAC
arrives.
The NAC code’s 12-bit fi eld ranges from hexadecimal $000 to $FFF and contains 4096 addresses
(signifi cantly more than the standard CTCSS and DCS tones).
The following NAC codes have specifi c functions:
$293 specifi ed as the default NAC value.
$F7E a receiver set for NAC $F7E will unsquelch on any incoming NAC.
$F7F a repeater receiver set for NAC $F7F will allow all incoming signals to be repeated with the
NAC intact.
(See Chapter 4; Figure 4-3)