Scanning Type I And Hybrid Trunked Systems - Radio Shack PRO-2052 Owner's Manual

20-432.fm Page 40 Friday, July 14, 2000 11:30 AM
Press to turn on priority
PRIORITY
scanning.
Note: Priority scanning does not work
if the ID is locked out.
SCANNING TYPE I AND
HYBRID TRUNKED
SYSTEMS
Your PRO-2052 is set to scan Type II
user IDs by default. When you scan
trunked frequencies, each Type II user
ID you see appears as an even num-
ber without a dash (such as 2160).
Your PRO-2052 can also scan Type I
trunked systems. Each Type I ID ap-
pears as a three- or four-digit number,
followed by a hyphen, followed by a
one- or two-digit number (such as
200-14).
If you notice a mix of odd- and even-
user IDs (such as 6477, 2160, 6481,
6144, and 1167), then you are proba-
bly monitoring either a Type I or hybrid
(a combination of Type I and Type II
user IDs) system. (See "Types of
Trunking Systems" on Page 30).
You might also notice that you are
missing responses when you hold on
an active ID. Unlike Type II systems,
Type I and hybrid systems require a
fleet map that sets specific fleet-
subfleet parameters. It is easy to se-
lect a fleet map to scan; what is not al-
ways easy is selecting or program-
ming a map that is being used in your
particular area.
40
When a Type I system is designed,
the address information for all its user
IDs is divided into 8 equal-size blocks,
numbered 0–7, and each block is as-
signed a size code. When you set up
your scanner to track a Type I system,
you must choose a size code for each
block. When you have chosen a size
code for all 8 blocks, you will have du-
plicated the fleet map for the system
you are tracking. If you have chosen
correctly, you will be able to track
transmissions in that system.
Each size code defines the number of
fleets, subfleets, and IDs each block
has. For example, you can see in the
following table that a size code of S4
has one fleet, which is divided into 16
separate subfleets, and it has a total
of 512 individual IDs.
Size Fleets Sub-
fleets
S0 Reserved block for Type II IDs
S1 128 4
S2 16 8
S3 8 8
S4 1 16
S5 64 4
S6 32 8
S7 32 4
S8 16 4
Size Fleets Sub-
fleets
S9 8 4
S10 4 8
IDs Block
Used
16 1
64 1
128 1
512 1
32 1
32 1
64 1
128 1
IDs Block
Used
256 1
256 1