Motorola APX 7500, Подробное руководство по обслуживанию

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68009482001 September 9, 2011
Feature Operation: Wireline Interface 4-9
If any other sequence of tones is received, the Consolette will consider the sequence invalid and will
ignore it in order to prevent unexpected behavior. Note that because the Consolette enforces
positive mode control, each PTT sequence must include a Channel Select command even if the
channel is not being changed.
The Consolette can detect Guard Tone in the range of -30dBm to +13dBm. The incoming HLGT is
by definition at the reference amplitude for tones received from the remote console. Therefore, once
the HLGT is detected, the Consolette will use its amplitude to calculate detection thresholds for
subsequent FTs and LLGT. The FT amplitude is nominally at -10 dB from the HLGT, so the FT
detection threshold will be set at -16 dB from the HLGT (one half of the nominal voltage) in order to
provide sufficient margin for detection. Similarly, LLGT is nominally at -30 dB from HLGT, thus the
LLGT threshold will be set at -36 dB from HLGT. If HLGT is at the rated wireline operating level of
775 mVrms, the resulting FT and LLGT thresholds will be calculated as 122.5 mVrms and 12.25
mVrms, respectively. Note that these thresholds are used for the detection of tones and are
calculated regardless of whether AGC is enabled.
4.12.2.3 TRC Command Handling
After receiving and validating a complete tone sequence representing a TRC command, the
Consolette acts on the command as appropriate. This involves sending one or more software
commands to the internally-housed mobile radio to cause it to enact the necessary changes.
The following TRC commands may be interpreted by the Consolette, causing it to take the actions
described:
4.12.2.3.1 Channel
The dispatch console user uses the Select Frequency command to change the Consolette’s radio
channel. This will select items such as a talk group and an air interface type. The number of
channels that can be changed by the dispatcher is 14.
NOTE: Selection of 16 channels is possible if the tone table is set up to not use Coded/Clear
operation.
When a Select Frequency command is received from the Console, the Consolette will send a
message to the mobile radio to steer it to the channel requested. The channel number from the
Console is mapped linearly to a zone and channel in the mobile radio. For example, if each zone has
5 channels, and the Console requests channel 8, the Consolette will steer the mobile to channel 3 in
zone 2. If the mobile does not allow the indicated channel, the Consolette will generate a “bonk” tone
and remain in the current channel.
NOTE: The Consolette is capable of 1250 channels and these can be accessed from the O5 control
head.
4.12.2.3.2 Coded/Clear
When a coded or clear (encryption on or off) command is received, the Consolette will send a
message to the mobile radio to set encryption to the indicated state. If the mobile does not allow the
indicated encryption state on the current channel, the Consolette will generate a “bonk” tone and
remain in the prior state.
Monitor HLGT-MON
PTT HLGT-CHAN-LLGT
PTT Coded HLGT-CODED-CHAN-LLGT
PTT Clear HLGT-CLEAR-CHAN-LLGT
Operation Tone Sequence