36
2. When the working channel assignment is received, the radio sounds a
single beep (Autokey alert tone) indicating it is ready for voice
transmission.
*
TXEMER
*
flashes on line two in the display until the
emergency is cleared.
3. Press PTT and speak into the microphone in a normal voice.
4. Release PTT when the transmission is complete and listen for a reply.
5. The emergency can be cleared by pressing and holding the
c
button
followed by pressing the
E
button then releasing both buttons.
SYSTEM SCAN OPERATION
The radio can be programmed with the following System Scan features. These
features are automatically enabled upon radio power up. A key or menu option
is also defined to allow the System Scan features to be toggled during radio
operation. This is covered in the Menu Selection and Pre-Programmed
Keypad Key sections. The System Scan state will be maintained through
system changes but will default to ON at power up.
Wide Area System Scan
The
Orion
radio may be programmed for wide area system scan operation for
multi-site applications. Upon the loss of the currently selected system's control
channel, radios may be programmed to automatically scan the control
channels of other systems. If a new control channel is found, the radio will
switch to the new system and sound an alert tone.
ProSound
The radio may be programmed for ProSound system scan operation for multi-
site applications. ProSound is an enhanced multi-site system-scanning
algorithm, compared to Wide Area System Scan. ProSound provides the radio
with the ability to select a new system for the radio to communicate on, when
the selected system drops below a predefined level. This is accomplished by
enabling each radio to analyze the signal quality of its current control channel
and compare it with the signal quality of the control channel for each site in its
adjacency scan list. (The signal quality metric used for the ProSound
algorithm is based on Digital Received Signal Strength Indicator (RSSI)
measurements). When the selected systems signal quality level degrades
below a pre-programmed level, the radio will begin to look for a better control
channel. Once a control channel that exceeds the pre-programmed parameters
is found, the radio will change to the new system and emit a tone. If the
control channel is completely lost the radio will enter Wide Area System
Scanning and search the programmed adjacent systems until a suitable control
channel is found.
