MULTI-NET SYSTEM OVERVIEW
5-8
Revised February 1997
Part No. 001-9750-005
with the proper key, communication is not possible.
The System Key is provided to the system operator by
the E.F. Johnson Company.
5.8.10 DYNAMIC CHANNEL ASSIGNMENT
When channels (repeaters) are added to a Multi-
Net system, mobiles do not have to be brought back in
for reprogramming because they are informed over the
air as to which channel number to use to place or
receive a call. The only channel numbers programmed
into the mobiles are the home and status channels.
5.8.11 EMERGENCY CALLS
An emergency switch is available with all Multi-
Net transceivers. This switch can be used in emer-
gency situations to quickly place calls or transmit an
emergency code. The transceiver can be programmed
so that the emergency message is transmitted either
automatically or manually.
When automatic operation is programmed, the
transceiver automatically transmits the emergency
code on the designated system/group until an acknowl-
edgment is received from the dispatcher. When
manual operation is programmed, the transceiver goes
to the designated system/group but no message is auto-
matically transmitted. This ensures that when the user
does transmit the message, it is transmitted at the
highest priority. Refer to Section 3.6.8 for more infor-
mation.
5.8.12 AUTO-REGISTRATION (ROAMING)
Auto-registration (roaming) can be used to auto-
matically track the location of mobiles in multi-site
systems. Calls can then be automatically routed to the
correct site. This eliminates the need to enter the site
of the mobile when placing a call.
Auto-registration occurs only when the mobile is
in the system scanning mode. If the mobile moves out
of radio range of the site in which it is currently regis-
tered, it begins searching for another site. When one is
found, it automatically registers on the new site. When
the transceiver is searching for a new site, the user is
alerted by a message in the display. Refer to Section
3.7.2 for more information.
Most Multi-Net transceivers also have a program-
mable parameter called Auto-Registration Dropout
Criteria. This parameter determines the point at which
the mobile attempts to register on another site. This is
controlled by the percentage of good data messages
that the mobile receives over a 10-second period. If it
is programmable, it can be set for 50-100%. If it is not,
it is fixed at 50%. This percentage sets the number of
good messages that must be received to stay on the
current site. Therefore, the higher the percentage, the
sooner auto-registration occurs.
5.8.13 BUSY QUEUING
The busy queuing feature places the call in a
queue if the system is busy when the PTT switch is
pressed. Then when the system becomes available, the
user is alerted by a tone and the call can be placed if
desired. An available system is determined in the
normal manner by the access priority of the selected
group and the current access priority being trans-
mitted by the repeater. Refer to Section 3.7.1 for more
information on this feature.
5.8.14 SENDING STATUS INFORMATION
One of up to eight preprogrammed status condi-
tions can be transmitted to the dispatcher. Conditions
such as “AT SCENE” or “IN PURSUIT” can be
selected by the user. Then when the transmitter keys, a
number representing that status is transmitted and a
message along with the mobile's unique ID are
displayed on the dispatcher's console. Refer to Section
3.7.3 for more information.
5.8.15 TRANSMIT INHIBIT
The Transmit Inhibit feature prevents the trans-
mitter from keying if the mobile being called is busy
with another call. The transceiver is programmed with
a block of transmit inhibit ID codes that can include up
to all 225. If a code within this block is detected up to
5 seconds before the push-to-talk switch is pressed, the
transmitter does not key and the user is alerted by a
tone and message in the display if applicable. Refer to
Section 3.7.5 for more information.
Summary of Contents for Summit DM 975x
Page 105: ...MULTI NET SYSTEM OVERVIEW 5 10 Revised February 1997 Part No 001 9750 005 ...
Page 108: ...CIRCUIT DESCRIPTION 6 3 August 1993 Part No 001 9750 001 Figure 6 1 Transceiver Block Diagram ...
Page 123: ...CIRCUIT DESCRIPTION 6 18 August 1993 Part No 001 9750 001 ...
Page 131: ...SERVICING 7 8 Revised January 1995 Part No 001 9750 003 ...
Page 156: ...9 19 Revised December 2000 Part No 001 9750 007 TRANSCEIVER EXPLODED VIEW PART 1 ...
Page 168: ...Revised January 1995 Part No 001 9750 003 10 11 INTERCONNECT SCHEMATIC ...
Page 169: ...Revised January 1995 Part No 001 9750 003 10 12 DISPLAY BOARD SCHEMATIC ...
Page 171: ...Revised January 1995 Part No 001 9750 003 10 14 RF BOARD SCHEMATIC REVISED 800 MHZ ...
Page 172: ...Revised January 1995 Part No 001 9750 003 10 15 RF BOARD BOARD LAYOUT ALL 800 900 MHZ ...
Page 173: ...Revised January 1995 Part No 001 9750 003 10 16 RF BOARD BOARD SCHEMATIC 900 MHZ ...
Page 174: ...Revised January 1995 Part No 001 9750 003 10 17 RF BOARD BOARD SCHEMATIC UNREVISED 800 MHZ ...
Page 178: ...Revised January 1995 Part No 001 9750 003 10 21 PA BOARD SCHEMATIC 900 MHZ 30W ...
Page 179: ...Revised January 1995 Part No 001 9750 003 10 22 PA BOARD SCHEMATIC 900 MHZ 15W ...
Page 181: ...Revised January 1995 Part No 001 9750 003 10 24 PA BOARD SCHEMATIC UNREVISED 800 MHZ 35W ...
Page 182: ...Revised January 1995 Part No 001 9750 003 10 25 PA BOARD SCHEMATIC UNREVISED 800 MHZ 15W ...
Page 183: ...Revised January 1995 Part No 001 9750 003 10 26 AUDIO LOGIC BOARD SCHEMATIC PART 1 OF 2 ...
Page 184: ...Revised January 1995 Part No 001 9750 003 10 27 AUDIO LOGIC BOARD SCHEMATIC PART 2 OF 2 ...
Page 185: ...Revised January 1995 Part No 001 9750 003 10 28 AUDIO LOGIC BOARD LAYOUT TOP VIEW ...
Page 186: ...Revised January 1995 Part No 001 9750 003 10 29 AUDIO LOGIC BOARD LAYOUT BOTTOM VIEW ...
Page 188: ...Revised January 1995 Part No 001 9750 003 10 31 REMOTE TRANSCEIVER INTERCONNECT SCHEMATIC ...
Page 189: ...Revised January 1995 Part No 001 9750 003 10 32 REMOTE CONTROL UNIT INTERFACE BOARD SCHEMATIC ...
Page 216: ...Part Number 001 9750 007 12 00 hph Printed in U S A ...
