User's Manual

20-527 Owner’s Manual Draft
Page 14 of 60
the east side patrol officers might all be assigned to talk group 2160. One channel in the system is
continuously transmitting data that identifies which talk groups are active on which channel. In addition,
this talk group information is also transmitted as subaudible data on each active channel.
When the scanner receives a transmission on a channel set to the Motorola mode, it first decodes the talk
group ID data included with the transmission. In the open mode, the scanner stops on the transmission
and displays the talk group ID on the bottom line of the display. In the closed mode, the scanner only stops
on the transmission if the talk group ID matches a talk group ID that you have stored in the bank's talk
group ID list and have not locked out.
Motorola trunking systems come in three categories: Type I, Type II, and Type I/II Hybrid. Each category
displays and uses talk group IDs in slightly different ways.
Motorola Type II IDs are in the form FFF-SS, where;
FFF=Fleet ID
SS=Subfleet ID
Type I systems are usually organized with different user groups assigned to different fleets.
Notes:
. For example, a valid fleet-subfleet ID identifying all detectives within a police department might be
000-12, where 000 identifies all police users and 12 identifies the Detective division.
. Tuning the scanner to an active control channel while in Motorola mode will display the Motorola
System. ID and the approximate control channel message decode success rate. This information can
help you identify the Motorola trunking system that you are monitoring and the receive quality of the
control channel signal.
To properly map the raw Type I data to the correct fleet-subfleet format, you must program the correct
fleet map into the scanner. Fleet map information is widely available on the Internet for most Type I
systems in use.
Type II system talk groups are identified by a 5-digit number. Valid talk group IDs are divisible by 16. If
you try to enter an invalid talk group ID, the scanner rounds the ID down to the next valid ID.
Type I/II hybrid systems use both fleet-subfleet and 5-digit formats for talk group IDs.
Note: If the scanner decodes control channel data while receiving transmissions from a Motorola
trunking system, CNTRL appears on the bottom line of the display.
EDACS Mode