User Manual

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Unlike most dispatch radio systems, however, an active transmission can be
pre-empted by a dispatcher or supervisor. This results in the transmitting radio
instantly switching to receive the “priority” in-bound call. Normal operation
can be resumed once the in-bound call is concluded. This feature is
particularly useful for V-TAC users operating as a scene commander.
2.1 VOICE OPERATION
The voice path operates like a traditional dispatch radio, with a microphone to
transmit (push-to-talk) and a speaker to receive. In OpenSky Trunked Protocol
(OTP), there is no separate voice and data path – all transmitted information is
digital.
2.2 DATA OPERATION
Data operation requires the connection of a laptop PC. OpenSky works
through standard IP protocols such as UDP/IP. The data path operates
similarly to the voice path, with a few differences. All external data
information in and out of the radio uses the RS-232 serial port connection.
2.3 REMOTE CONTROL HEAD OPERATION
For remote mount installations configured with a CH-103 control head, all
normal radio operations and interfaces can be made remotely from the radio
unit via the remote control head connected to the radio unit by a single
twisted-pair connection that is easy to route through a vehicle. Up to six
control units may be attached to a trunk mount radio or V-TAC. Each control
head provides a serial access point for data and any one (only one at a time) of
these can be connected to a data device such as a personal computer.
Where multiple control heads are connected, or where a dash-mount radio is
installed with additional remote control heads, several other features are
available from each position:
• Outgoing voice calls can be initiated. (Any control head can initiate a call
but only one can talk at a time. All other connected control heads will
hear both sides of the conversation.)
• Incoming and outgoing audio can be heard. (Outgoing audio is not
broadcast at the source position.)
• Independent audio control is available.
• Radio settings such as talk group, scan mode etc., can be controlled. (Any
connected control head can override the radio settings of other connected
control heads.)
• Comfort settings, such as volume and display brightness that are
applicable to the individual control head can be adjusted and cannot be
overridden by other control heads.