68009482001 September 9, 2011
Feature Operation: Wireline Interface 4-7
NOTE: For instructions on configuring the Consolette for Tone Remote Control operation, see section
3.7.3.1.
Figure 4-3. APX 7500 Consolette to MCC7500 topology
4.12.2.2 TRC Command Decoding
When TRC functionality is enabled in the Consolette codeplug, and when the TX wireline input of the
codec is selected, the Consolette will monitor the incoming wireline audio for the presence of TRC
tone sequences. The exact sequence of tones received from the console or deskset varies
depending on the command being represented, however the sequence always follows the general
pattern:
1. High-level guard tone (HLGT) for 120 ms @ 0 dB (nominal amplitude)
2. Function tone 1 for 40 ms @ -10 dB relative to HLGT
3. Function tone 2 (optional) for 40 ms, @ -10 dB relative to HLGT
4. Low-level guard tone (LLGT) for the duration of PTT @ -30 dB relative to HLGT, absent for all
commands other than PTT
Figure 4-4 illustrates the sequence of tones involved in a line push-to-talk (LPTT) function.
Figure 4-4. Remote Key-Up
A HLGT initiates all tone sequences and provides both a trigger for the Consolette to begin analyzing
the sequence as well as a reference amplitude for detecting subsequent tones. LLGT is used to
indicate that a PTT is occurring, where the PTT lasts for the duration of the LLGT.
APX 7500
Consolette
CCGW with
TRC
MCC7500
Wireline (audio)
X-Zone
Distance: distance of leased
line capacity
Distance: distance of LAN capability
HLGT
FT
Voice
Amplitude
Time
40ms
120ms
LLGT
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