Service manual

OPERATION
3-22
Revised December 2000
Part No. 001-9750-007
Landside-Originate Special Calls
Calls can be also be made from any landside tele-
phone to specific mobiles (Interconnect calls) or
groups (Directed Group calls). Calls can also be
placed to other sites in a manner similar to when they
are mobile dialed.
If the system has DID lines, the landside caller
can dial a mobile directly because each mobile that
can receive these calls is given its own phone number.
If the system has standard trunk lines, the telephone
number of the system is dialed. Then when the system
answers, a short tone sounds to indicate that the digits
specifying the destination of the call should be dialed.
The same digits are dialed as when the call is mobile
originated as described in “Placing a Special Call”.
The landside telephone must generate DTMF tones to
dial these digits.
After these digits are dialed, a beep is heard
which indicates that the number was accepted by the
system. Ringing then indicates that the mobile is being
rung unless it is a Directed Group call. With those
calls, no ringing of the mobile occurs and another beep
is heard which indicates the path is complete and
speaking should begin.
After the mobile answers, the landside party
should respond in the normal manner. Remember that
the mobile is operating half duplex and cannot hear the
landside party while transmitting. When the call is
finished, it should be terminated by one of the parties
by pressing the # key. Three beeps indicate that the
call has terminated.
3.7.5 TRANSMIT INHIBIT
This feature prevents the transmitter from keying
if the party being called is busy with another call. To
enable this feature, the transceiver is programmed with
a block of transmit inhibit ID codes that can include up
to all 225 standard ID codes with Multi-Net operation,
or up to all 250 ID codes with LTR operation. If a code
within this block has been detected up to 5 seconds
before the PTT switch is pressed, the transmitter does
not key, the intercept tone sounds, and “TX INHIBIT”
is indicated in the alphanumeric display.
To make another call attempt, the PTT switch
must be released and then pressed again. However, it
is a good idea to wait a few seconds because the 5-
second timer does not count down while the PTT
switch is pressed. It is not possible to complete the call
by keeping the PTT switch pressed with the intercept
tone 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 could be to provide an audible indica-
tion that the party being called is busy. This feature is
available only on Multi-Net and LTR systems. A
similar Transmit Disable On Busy feature is available
on conventional systems.
3.7.6 ACCESS PRIORITY (MULTI-NET)
Refer to Section 5.8.2.
3.7.7 CAMP-ON PREVENT
This feature prevents a user from “camping on” a
channel by continuously pressing the PTT switch
while a message is being received. When the Camp-
On Prevent feature is programmed and the user presses
the PTT switch while a message is being received, the
transmitter is disabled, “TX DIS BSY” is displayed,
and the dial tone sounds until the PTT switch is
released. Therefore, accesses can be attempted only by
pressing the PTT switch during quiet times.
This feature is available only when placing Multi-
Net standard (mobile-to-mobile) calls. In addition, the
selected encode ID must be the same as the ID on
which the call is being received. It is not available
with Multi-Net special calls or any type of LTR or
conventional call. In addition, transceiver software,
Version 223 or later and programming software,
Version 207 or later, must are required.
When this feature is not used and the PTT switch is
pressed while a message is being received, the message
continues to be received normally and access is auto-
matically attempted as soon as the message is complete.
If a large number of mobiles do this during busy periods,
collisions may occur and the “camping” mobiles may
have a better chance getting a free channel.