User's Manual

In a two-tone call, the mobile sends the collected tone
for a programmable duration. In the four-tone call, the mo-
bile always sends a 90-millisecond collect tone which the
repeater regenerates and sends for the correct duration.
Group/Individual Tones
Group/Individual Tones chosen from the 34 standard
frequencies follow the collect tone. In a two-tone call, the
second tone is sent for 450 milliseconds. In a four-tone call,
the second, third, and fourth tones are sent for 90 millisec-
onds from the mobile and 180 milliseconds from the re-
peater.
RADIO OPERATION
A complete set of operating instructions for the Dual
Format MDX are provided in LBI-38846 and are provided
with each radio.
This radio is flexible in operation and can be used in any
of three operating modes: Conventional radio system, En-
hanced Digital Access Communications (EDACS) system,
or GE-MARC (tone controlled) system. Either of the latter
two systems provide trunked channel selection for increased
channel utilization.
In an EDACS trunked environment, the user selects a
communications system and group. In this mode, audio
channel selection is transparent to the user and is controlled
via digital communication with the system controller. This
mode incorporates advanced programmable features and fast
access to communication channels.
In a GE-MARC trunked environment, the user selects a
communications area and group. In this mode, audio channel
selection is also transparent to the user and is controlled via
tone signalling.
In Conventional mode, the user selects a channel and
communicates on that channel. In this mode, a system refers
to a set of channels and a channel is a transmit/receive radio
frequency pair.
The exact operation of any radio depends upon the
operating mode, the programming of the radio and the par-
ticular radio system. Most features described in these oper-
ating instructions can be enabled or disabled through
programming. Both of these important factors must be con-
sidered when addressing the following instructions.
USER INTERFACE
Operating controls are located on the radio front panel
and microphone.
The front panel LCD provides radio status and commu-
nication control information to the operator. The keypad is
used for manual number entry for individual calls access to
a telephone interconnect system and activation of various
EDACS, GE-MARC, and conventional features.
Turning The Radio ON/OFF
The radio is turned ON/OFF by pressing the PWR
button in the upper left corner of the front panel. A self
diagnostic test is performed when the radio is first turned on
if enabled through programming. To turn the radio OFF,
press the PWR button again.
ALERT TONES
The Dual Format MDX radio generates a set of unique
alert tones to indicate operating status. The following section
identifies and describes the alert tones used in the Dual
Format MDX radio for Conventional, GE-MARC, and
EDACS applications.
EDACS APPLICATIONS
CALL
ORIGINATE
ALERT
If programmed, a short tone is sounded
whenever the Push-To-Talk key is
pressed and the radio has acquired a
channel. This tone indicates the user can
begin communications.
CALL QUEUED If one short, high-pitched tone sounds
after the transmitter is keyed, this indi-
cates that the system has placed the re-
quest in a queue. This tone sounds at both
the transmitting unit and the receiving
unit(s) indicating to the user on the re-
ceiving end that a call is being directed
to them. If the PTT is unkeyed while in
the queue, the radio autokeys (automat-
ically keys) Push-To-Talk when a chan-
nel becomes available (see AUTOKEY).
AUTOKEY When the PTT is keyed to place a call on
the system, but the PTT is released be-
fore getting to the channel (e.g. a queued
call), the radio automatically keys on the
channel when it gets the assignment. The
radio generates a long beep and holds the
transmitter keyed for two seconds. Press-
ing the PTT button keeps the channel and
sends the message before this two sec-
ond time-out has expired.
SYSTEM BUSY If you press the PTT key and hear three
short, medium-pitched tones, this indi-
cates that the receiving party is already
on the system or the system is busy and
its queue is full. You must rekey later to
access the system.
CALL DENIED A single, low-pitched beep sounds when
the PTT key is pressed and the request is
denied by the system. This happens if the
unit is an invalid user or if the unit is
requesting an unavailable service.
OUT-OF-
RANGE/
SYSTEM
INOPERATIVE
A single, low-pitched tone sounds immedi-
ately after the PTT key is pressed indicat-
ing the radio is out of range of the repeater.
The radio tries to place the call for a short
period (3 seconds) after the initial attempt.
The radio generates a second low-pitched
tone when it gives up trying to place the
call. These tones are also heard if the sys-
tem is off the air or the radio needs servic-
ing (even when the radio is within calling
range of the repeater).
GE-MARC APPLICATIONS
CALL
RECEIVED
ALERT
If programmed, a single alert tone sounds
when a group call is received and a two-
tone alert (one high followed by one low
tone) sounds for an individual call.
CALL
ORIGINATE
ALERT
WA I T momentarily displays when a call is
being placed. Then a three-tone alert is
sounded to indicate the call origination is
complete. This indicates a channel was ac-
quired and is ready for normal conversa-
tion.
INVALID CALL
ORIGINATE
ALERT
A low-frequency tone is sounded for one
second immediately after pressing PTT and
the display does not show WA I T. This in-
dicates a call was attempted within a group
that is not enabled for call originate or an
invalid dispatch overdial call was at-
tempted.
SYSTEM
TONES
A low-frequency tone is sounded for one
second after attempting to place a trunked
call and BUSY is displayed. This indicates
that the GE-MARC system is busy. If the
"Call Retry" option has been enabled
through programming, the radio retries at
5 second intervals up to 15 times unless
END is pressed, a channel is acquired, or
an out-of-range condition occurs.
OUT-OF-
RANGE
ALERT
If NO SVC is displayed and five beeps are
sounded after attempting to place a trunked
call, the radio is out of range of the GE-
MARC system. If the beeps sound when
the radio is within known range of the
system, the radio may need servicing. If the
"Call Retry" is active, the radio tries the
channel at twenty second intervals for five
minutes.
CARRIER
CONTROL
TIMER
(GE-MARC and Conventional operation.)
A pulsed-tone signal is sounded for a pre-
programmed time after PTT is pressed. Af-
ter nine seconds of pulsing the alert tone,
the radio unkeys the transmitter and com-
munications are interrupted. While the tone
is pulsing, the user can release and press
PTT again to reset the timer and resume the
conversation. In the conventional mode,
the radio unkeys and beeps until PTT is
released.
SYSTEM
TONES
The GE MARC radio may generate other
system tones to alert the user of custom
programmed events. Contact the GE-
MARC system operator for details about
these alert tones.
LBI-38848D
6