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Configuring Dual Channel Cards
Channel Cross-Mute
Each channel may be configured so that the external cross-busy input (Busy In) will also
mute the receive audio of the channel to all console positions. This is useful to prevent
audio feedback between consoles present in the same room.
If you need to cross mute more than three consoles, call ZETRON Technical Support for
guidance.
Tone Control, HLGT Duration
When a channel is programmed for tone remote control, the OPT switch allows selection
between the standard HLGT (high-level guard tone) duration (120 milliseconds) or the
custom HLGT duration (defined via CPSW). Placing the switch in the OFF position
selects the standard duration. Placing the switch in the ON position selects the custom
duration.
DC Current Control — Current Selection
To control transmission using DC current, the optional DC Remote Daughter Board must
be installed on the Dual Channel card for that specific channel. When the daughter board
is installed, the OPT switch controls the current setting level for transmission. In the OFF
position, the standard Zetron level, which is appropriate for most applications, is used. In
the ON position, the standard Motorola/GE settings are used.
Full Duplex
Each channel may be configured for full duplex or simplex operation. Full duplex
operation requires a 4-wire system and allows the dispatcher to transmit and receive
simultaneously (like a telephone). Simplex (or half-duplex) operation may either be a 2-
wire or 4-wire system, and allows the dispatcher to transmit or receive but not both
simultaneously. This switch selectable option prevents dispatchers in full duplex operation
from hearing themselves, and thus prevents feedback.
LOTL Disable
The option boards, DC Remote Daughter Board and Tone Remote LOTL Daughter Board,
may be configured to ignore LOTL parallel remote transmit signals. Note that when
parallel control points are used, the FCC requires that the LOTL function be enabled. If no
parallel control points are installed, it may be desirable to disable the LOTL function,
because when enabled, the LOTL function operates even when this console is
transmitting.
