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8/17/2015
Pause Mode the mode the radio is in while paused on a scan; service, limit, or tune search.
Searching the process of searching for active frequencies in preprogrammed service searches, programmed frequency bands, or the limit search.
Manual Mode used for browsing and monitoring a channels.
Program Mode used for storing frequencies, limit searches, priority channels, trunking frequencies/systems/fleet maps, and talkgroup ID lists.
Trunk Mode used for trunking and programming trunking frequencies and functions.
Clone Mode used for cloning scanners and uploading/downloading to/from scanners using a computer.
At certain times, the radio can be in more than one mode at a time such as program and trunk mode to program trunked functions.
Trunking systems let a large group of 2way radio users (or even different groups of 2way radio users) efficiently use a set of frequencies. Instead of selecting a specific frequency for a
transmission, the user's radio selects a programmed trunking bank in the system when that user presses their PTT (push to talk) button. The trunking system automatically transmits the call on
the first available frequency, and also sends (on a different frequency called a Data or Control channel) a code that uniquely identifies that transmission as a talkgroup ID (or just ID.) So when
you are trunktracking a system, you are listening to active IDs transmitting in the system (each using the first available frequency in the system.) Trunking systems in general allocate and use
fewer frequencies among many different users.
Since the trunking system might send a call and its response on different frequencies, it is difficult to listen to trunked communications using a conventional scanner. These scanners let you
monitor the control channel frequency so you can hear calls and responses for users and more easily "follow" conversations than with a conventional scanner.
These scanners trunktrack the following types of systems:
Motorola Type I
Motorola Type II
Motorola Type IIi Hybrid
Motorola Type II Smartnet
Motorola Type II Smartzone
When you program Motorola and EDACS system frequencies into the scanner, one frequency is the control (or data) channel, and the rest are voice frequencies shared by all the users. There
may be 3 or 4 frequencies assigned as (primary or alternate) control channels but only one control channel will be active at a time. These scanners will allow you to program just Motorola control
channels into the trunking system and the voice channels will automatically be found (but not programmed). EDACS systems need all the frequencies for the system programmed and in the
correct LCN (Logical Channel Number) order.
The control channel is continually transmitted to the field units and has a sound similar to listening to a boat engine over the phone (in manual mode; you won't hear this when you are trunking
the system.) This control channel is also a good check to see if you can trunktrack the system. If you can't hear a control channel when you step through the trunking frequencies (in manual
mode), you either don't have all the frequencies or are too far away to receive the control channel and the system. Motorola systems are limited to a maximum of 28 frequencies per system or
site. Ericsson EDACS systems are limited to 25 frequencies per system or site. Motorola and EDACS systems can be either analog, digital, or mixed (digital and analog talkgroups). These
scanners can't monitor digital systems.
LTR systems work a little differently. LTR systems typically do not have a dedicated control channel. This type of system encodes all trunking information as digital subaudible data that
accompanies each transmission. The frequencies also have to be in LCN (Logical Channel Number) order or the correct 'slot' for the system to trunktrack properly. The Repeater Finder Tool will
help you determine the correct order. Each repeater has its own controller, and all of these controllers are synchronized together. Even though each controller monitors its own channel, one of
the channel controllers is assigned to be a master that all controllers report to. Each of these controllers sends out a data burst approximately every 10 seconds so that the subscriber units know
that the system is there. This data burst is not sent at the same time by all the channels, but happens randomly throughout all the system channels. If you listen to the frequencies of an LTR
system in manual mode (not trunking), on every channel in the system you will hear this data burst that will sound like a short blip of static like someone keyed up and unkeyed a radio within
about 500 msec. LTR systems are limited to 20 frequencies per system.
Trunkscanning is basically scanning IDs that are programmed into ID locations (same concept as frequencies into channels.) You can then trunkscan just the programmed IDs. Trunktracking is
searching for all IDs in a system (same concept as searching for frequencies in a band.)
Radio Reference.com has an excellent page explaining the various types of trunking systems in more detail here.
Channel Storage Banks
The radios have 10 banks of 100 channels. Channel numbering starts with 000 and goes to 099 in the first bank. Banks number 09. You can also program your trunking frequencies and
conventional frequencies into the same bank as well to utilize channel space better.
Use each channelstorage bank to group frequencies, such as those for police, fire, ambulance, aircraft, and/or trunking systems. For example, your police department might use 20 frequencies
while the fire department uses 15 and a trunked EMS systems uses 5 trunked frequencies. You could program the EMS frequencies starting with channel 000, (the first channel in bank 0), the
police frequencies starting with channel 005, and the fire department frequencies starting with channel 025. EDACS systems have to start at channels 001, 101, 201, etc. and follow a LCN order
but you can still use 000, 100, 200, etc. for a conventional frequency.
For each trunking bank, you can put in one EDACS system (with conventional frequencies), or one Motorola system and/or an LTR system (with conventional frequencies). However, if you store a
Motorola system and an LTR system in one bank, the bank mode has to be set to MO (Motorola). If it is set to LT (LTR), the Motorola control channel will break the squelch and hang the scanner
on that channel.
Also,
(1) if you scan this bank in open mode, you will hear all Motorola IDs and LTR transmissions (IDs will be incorrect because the bank is set to receive Motorola IDs).
(2) If you scan this mixed bank in closed mode with Motorola IDs programmed, you will hear just the programmed Motorola IDs.
(3) You will hear the data bursts from the LTR system about every 5 seconds so you should set the delay for these channels accordingly.
Tip: Theoretically, you could also program more than one (of the same type i.e. Motorola) trunking system into a bank as long as you could only monitor one at a time, in different locations, far
enough apart, so the system you are monitoring wouldn't interfere with the other system (which would confuse the radio). But remember, the scanner can be set to decode only one type of ID
(MO, ED, or LTR) per bank.
Service Search Bands
The scanners also have 6 service bands preprogrammed with frequencies and 1 limit search to allow you to create your own search band. Search bands SR3 (Police/Fire), and SR5 (Amateur)
are divided into groups or subbands of frequencies that can be turned on or off within the bands.
Motorola IDs come in two formats: Type I and Type II. Each format displays and uses Talk Group IDs in slightly different ways. Type I/II hybrid systems use both Type I and Type II formats for Talk
Group IDs.
Type I IDs are in the format FFFSS where FFF is the fleet and SS is the subfleet. Type I systems are usually organized with different IDs assigned to different fleets. For example, a
valid fleet/subfleet ID identifying all detectives within a police department might be 00012, where 000 identifies all police IDs and 12 identifies the Detective division. To properly trunk a
Type I system, you have to program the fleet map for the system.
Type II IDs are identified by a 5digit number. Valid (programmable) Talk Group IDs are divisible by 16.
EDACS IDs come in two formats: AFS (AgencyFleetSubfleet) and Decimal.
http://marksscanners.com/97/97.shtml#open_closed
Easier to Read Pro97/2055 Scanner Manual
Understanding Trunking
Motorola Type II Smartzone Omnilink
EDACS Standard (Wide)
EDACS Networked (Wide)
LTR Standard
Understanding Banks
Understanding IDs
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