Network Access Code (Nac); P25 Group Calls; P25 Unit Calls - E.F. Johnson Company 5300 SERIES Operating Manual

receive the call. A call is received on a channel if a
selected or scanned channel is programmed with that
ID and the correct NAC is detected (see following).
Group IDs can be any number from 0-65,535. Group
ID detect can be disabled by the Normal/Selective
squelch function described in Section 5.5 and the
Monitor Mode described in Section 5.3.

5.16.3 NETWORK ACCESS CODE (NAC)

Project 25 conventional channels also use a NAC
(Network Access Code) to control which calls are
received on a channel. The NAC can be 0-4095, and
each transmit and receive channel can be programmed
for a different code. Other operation, such as moni-
toring before transmitting, is similar to that of analog
channels. NAC (and group ID) detect can be disabled
by the monitor mode described in Section 5.3.

5.16.4 P25 GROUP CALLS

General
P25 Group calls are placed by simply selecting
the channel programmed for the desired group, moni-
toring the channel if required, and transmitting. When
a P25 group call is received, the alias (or frequency) of
the selected channel is displayed. The radio can be
programmed so that the following are also displayed
for 0.5-7.0 seconds or continuously during the call.
P25 PTT ID - The unit ID of the mobile placing
the call is displayed.
P25 Talk Group - The alias of the talk group on
which the call is being received is displayed.
User Group ID* - If the group ID of the call
being received is included in a preprogrammed
User Group ID list, the alias programmed in that
list for that group is displayed.
Changing Talk Group Assigned To a Channel
If the TG SEL option switch is programmed, the
talk group assigned to a channel can be changed by the
user. The new talk group continues to be assigned to
the channel until it is manually changed again (cycling
power or selecting another channel does not reselect a
* This feature requires firmware 1.24.1/2.2.1/3.2.1/4.2
or later.
default talk group). Change the talk group assigned to
a channel as follows:
1. Select the channel to be changed and then press the
TG SEL option switch.
2. Rotate the Select switch to display the talk group to
be assigned to that channel. Talk groups are indi-
cated by a unique identification in the alphanumeric
display.
3. To select that talk group and return to normal oper-
ation, press the TG SEL switch again or press the
Select switch. If talk group selection has been
disabled on the channel by programming, the talk
group does not change, "NO LIST" is displayed,
and a tone sounds.

5.16.5 P25 UNIT CALLS

Unit calls (also called Individual Calls) can be
placed to a specific radio on Project 25 channels If the
CALL option switch is programmed. Only the indi-
vidual ID of the target radio is sent (a talk group ID is
not sent). The mobiles that can be called are prepro-
grammed in the Unit Call list.
To receive a unit call, the RF channel of the call
must be selected or scanned and the correct NAC and
unit ID must be detected. The ID of the calling radio is
then transmitted back. To respond to the call, the radio
must be programmed with the CALL option switch,
and have a Unit Call programmed with the ID of the
calling mobile.
Place and receive a Unit Call as follows:
1. To transmit a unit call, press the CALL option
switch. The alias (tag) of the last Unit Call is
displayed.
2. If required, rotate the Select switch to display the
desired call. The alias and ID of the unit calls that
have been programmed are alternately displayed.
3. Press and then release the PTT switch. Ringing is
then heard and "WAIT" displayed to indicate that
the mobile is being rung. To disable this ringing but
not the call, briefly press the PTT switch again.
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CONVENTIONAL FEATURES