Repeater Talk-Around; Displaying Transmit/Receive Frequency; Emergency Alarm And Call; Introduction - E.F. Johnson Company 4100 SERIES Operating Manual

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It can be programmed for times up to 7.5 minutes.
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It is reset when the time between transmissions
exceeds the time programmed for the penalty timer.
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A warning beep sounds 5 seconds before this timer
disables the transmitter.
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When this timer disables the transmitter, a contin-
uous tone sounds and the red transmit indicator
turns off. The PTT switch must then be released
until the penalty timer expires (indicated by a beep).

5.8 REPEATER TALK-AROUND

Normally, all transmissions go through a repeater
which usually increases range. However, there may be
times when a user is out of range of the repeater and
therefore unable to talk to anyone even though the user
being called is only a short distance away. To allow
communication in this situation, repeater talk-around
can be selected. Transmissions then occur on the
receive frequency which permits direct radio-to-radio
communication.
Repeater talk-around can be selected if the RTA
option switch or menu parameter is programmed.
When talk-around is enabled by this switch,
displayed. This feature remains enabled during scan-
ning, and changing channels or turning power off does
not change the selected condition. Talk-around is
available on conventional channels only, and power
output is reduced in this mode.
5.9 DISPLAYING TRANSMIT/RECEIVE
FREQUENCY
If the Displayed Information option switch or
menu parameter is programmed (see Section 4.1), it can
be used to display the channel frequency in megahertz.
Pressing this switch toggles between displaying the
standard channel alias and the channel frequency. The
receive frequency is displayed when receiving and the
transmit frequency is displayed when transmitting. This
feature is available on conventional channels only.

5.10 EMERGENCY ALARM AND CALL

5.10.1 INTRODUCTION

Emergency Alarms and Calls are separate func-
tions that can be individually enabled or disabled on
each analog and P25 conventional system. The Emer-
gency option switch or menu parameter is required for
these functions. Emergency Alarms and Calls are
transmitted on the global (radio wide) emergency
zone/channel if one is programmed. If it is not
programmed, the emergency is transmitted on the
selected channel. The emergency programming of the
system to which that channel is linked controls the
emergency operation.

5.10.2 EMERGENCY ALARMS

An emergency alarm is a special transmission that
alerts a dispatcher of an emergency situation. It is sent
automatically by simply pressing the Emergency
option switch or selecting the Emergency menu
parameter. The system to which the emergency
channel is linked must have Emergency Alarms
enabled. If it does not, Emergency Alarms are
disabled.
In the P25 conventional mode, a special P25
emergency data transmission is sent, and in the
conventional analog mode, an DTMF emergency ID is
sent. This ID is programmed on the Conventional
is Radio Wide screen. Refer to Section 5.15 for informa-
tion on MDC1200 Emergency Alert.
Proceed as follows to send an emergency alarm:
1. If required, select a channel of a system on which
Emergency Alarms are enabled and then press the
Emergency option switch or select that menu
parameter. The radio then automatically transmits
the emergency alarm.
2. Either Normal or Silent operation can be
programmed. With Normal operation, the red LED
lights, the emergency tone sounds, and
"EMERGNCY" flashes in the display. This indica-
tion continues to flash until the alarm mode is ended
(see step 4). If silent operation is programmed or the
Surveillance mode is selected (see Section 4.7),
none of these indications occur. If "No Receive
Activity During Emergency" is programmed,
receive audio, the front panel LED, and receive
icons are disabled in the receive mode.
3. When the emergency alarm is acknowledged by the
dispatcher, "ACK RCVD" is briefly displayed and
the emergency acknowledge tone (two beeps)
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CONVENTIONAL MODE FEATURES