Service manual

OPERATION
3-26
April 2001
Part No. 001-9800-203
3. Ringing is then heard by the landside caller while
the mobile is being rung.
3.8.6 TRANSMIT INHIBIT
This feature prevents the transmitter from keying
if the mobile being called is busy with another call. To
enable this feature, the LTR system is PC programmed
with a block of transmit inhibit ID codes that can
include up to all 250. If a code within this block is
detected up to 5 seconds before the PTT switch is
pressed, the transmitter does not key, the intercept tone
sounds, and “TX INHIB” is displayed.
To make another call attempt, the PTT switch
must be released and then pressed again. Although the
5-second timer does count down while the PTT switch
is pressed, it is not possible to complete the call by
holding the PTT switch down until the intercept tone
stops sounding.
One use of this feature is to prevent the accidental
interruption of a call in progress. This could happen
when the other transmitting party unkeys or if an ID
code with a higher priority is transmitted. Another use
of this feature is to provide an indication that the
mobile being called is busy. A similar Transmit
Disable On Busy feature is available on conventional
systems.
3.8.7 BUSY QUEUING
NOTE: This feature replaces Free System Ringback
used in some earlier LTR transceivers.
The busy queuing feature places a telephone call
in a queue if the radio system is busy when it is placed.
Then when the system becomes available, it is auto-
matically accessed. Dispatch (mobile-to-mobile) calls
are not queued by this feature. Busy queuing is
enabled or disabled on each LTR system by PC
programming. It is not selectable by the user.
If queuing is programmed and a busy condition is
encountered, the queue mode is entered automatically
when the PTT switch is released. The queue mode is
indicated by “IN QUEUE” on the bottom line of the
display (high tier models). Then when the radio
system becomes available, the transceiver waits a
random time and attempts to access the repeater. This
random delay minimizes the chance of collisions with
other transceivers in queue.
If an access attempt is unsuccessful, another
attempt is made after another random delay. This
continues until an attempt is successful. A beep then
sounds and the dial tone is heard. The number can then
be dialed if desired. If a number is not dialed soon
after the dial tone sounds, the call is automatically
terminated.
The queue mode is exited before placing the call
if any of the following occur (with high tier models,
“IN QUEUE” is no longer displayed when exit
occurs).
• The PTT switch is pressed
• Any call is received
• Any option switch is pressed
• Power is turned off
Calls are received normally in the queue mode;
however, the queue mode is exited as indicated above.
Group scanning remains enabled while in the queue
mode, but system scanning is temporarily disabled.
3.8.8 SYSTEM SEARCH
If an out-of-range condition exists when
attempting an LTR telephone call, this feature auto-
matically searches for a system within range. With the
high tier models, the system search feature can be
enabled and disabled by the user if the menu SYS
SRCH parameter is selectable (see Section 3.6.13).
Otherwise, it is enabled or disabled on all LTR
systems by programming.
The system search mode is automatically entered
when the PTT switch is released. The bottom line of
the display indicates “SYS SRCH” (high tier only) and
a tone sounds when this mode is selected. The trans-
ceiver then attempts to access, in succession, other
systems that have any group programmed for tele-
phone calls. As each system is searched, a beep
sounds. Each system is accessed only once.
If no system could be accessed, the intercept tone
sounds, “NO PHONE” is displayed (high tier only),
the system/group does not change, and the feature
deactivates. If a system is accessed, the new system/