GAI-Tronics L3149B C200 Advanced Deskset - Manual (Page 53)

L3149B (C200) Advanced Tone Remote Desk Set Programming
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Control Parameters
Guard Tone Frequency
The guard tone frequency is available when the type of interface is Tone or Tone with E&M control.
This parameter allows the selection of the guard tone frequency for transmit and receive. Different guard
tone frequencies are available for installations requiring them or where paging tones within the guard
tone notch are needed. The tone adapter must be configured for the same guard tone frequency.
Guard Tone Duration
When the type of interface is Tone or Tone with E&M control, the guard tone duration is typically 120
ms for most installations. Installations using older tone remote adapters or radio-frequency links to the
tone remote adapter may need this time extended to allow more time for decode or time for the RF link to
be established. The valid range is 120 ms to 2500 ms in 10 ms increments.
In addition, the display will show
WAIT
during this time so that the operator will know when to speak for
voice transmissions. The mic delay can be programmed for this duration to remove the need for the
operator to wait to speak. The range is 10 ms to 2000 ms in 10 ms increments.
Function Tone Level
When the type of interface is Tone or Tone with E&M control, the function tone level can be adjusted
to be the same or 10 dB less than high-level guard tone. Typically, most systems can operate with either
setting. However, some systems require the function tone level to be 10 dB less than high-level guard
tone. Select the levels for these tones as 0 dB and -10 dB (default).
Function Tone Duration
When the type of interface is Tone or Tone with E&M control, the duration of the function tone is
typically 40 ms for most systems. However, some systems may require a longer duration for proper
decoding. This parameter allows the duration of the function tone to be set from 40 ms to 2420 ms in
10 ms
increments.
Low Level Guard Tone Level
When the type of interface is Tone or Tone with E&M control, the low level guard tone level is
typically 30 dB below high level guard tone. However, poor phone lines exhibiting high loss may cause
the tone remote adapter or parallel units to lose low-level guard tone detection during transmission. In
these cases, the low level guard tone level can be set to be 20 dB below high-level guard tone. This may
be necessary if line losses exceed 20 to 25 dB.
Mic Delay
To allow the dispatcher to speak immediately after pressing PTT, a continuous mic delay is employed to
reduce the possibility of clipped syllables. This delay allows the generation of high-level guard tone and
function tone or dc current to be done while the dispatcher is speaking. This parameter should normally
be set to the sum of the guard tone and function tone durations or the minimum dc duration. It is possible
to program the delay for 0 to 750 ms.
Note that after releasing PTT, the unit remains keyed for the programmed delay time to allow the
remaining dispatch audio to be transmitted. This delay is not used for intercom, paging, alert tone or
MDC1200 transmissions.