GatesAir PT-353, Инструкция по установке и эксплуатации, Страница: 22 / 55

PT/PR-353 Program Audio Module Installation & Operation Manual 3 – Installation & Operation
Version 1.1
3-8 GatesAir
Intraplex Products
3.3.2.4 Pre-Emphasis/De-Emphasis (Position 6 – PT-353 SW6 and PR-353 SW2)
Select J.17 pre-emphasis and de-emphasis on or off using the pre-emphasis/de-emphasis switches
(Position 6 – PT-353 SW6 and PR-353 SW2). The J.17 pre-emphasis/de-emphasis is applied to the
analog input/output only. To activate J.17, set PT-353 SW6 or PR-353 SW2 Position 2 DOWN. To
deactivate J.17, set PT-353 SW6 or PR-353 SW2 Position 2 UP.
J.17 emphasis is usually not necessary to achieve the high levels of performance available from these
modules and it is generally recommended that J.17 emphasis not be used. Particular attention should
be paid when using these modules’ dual domain features. J.17 pre-emphasis/de-emphasis is applied
only to the analog input and output. Any analog emphasis does not receive complimentary de-
emphasis on the digital output and vice versa. The J.17 emphasis curve is not compatible with and
should not be intermixed with any other pre-emphasis schemes.
3.3.2.5 DC Offset Removal (Position 7 – PT-353 SW6)
Offset enable provides DC offset removal in DSP (digital signal processor). Set this switch DOWN to
enable Offset Removal. With DC offset removal engaged, some frequency response below 20 Hz is
rolled off.
3.3.2.6 CAS Support (Position 8 – PT-353 SW6 and PR-353 SW2)
CAS is used in EI systems to provide telephone on-hook/off-hook signaling in time slot 16. If your
PT/PR-353 modules are being installed in an Intraplex E1 multiplexer containing telephone modules
that are using signaling, configure them to support CAS signaling by skipping time slot 16. To activate
CAS support, set the CAS switch on (Position 8 DOWN on PT-353 SW6 and PR-353 SW2). If the
modules are used in a T1 multiplexer, CAS signaling must be switched off.
3.3.2.7 SPARE (Position 9 – PT-353 SW6)
This switch is a spare at this time. Set this SPARE selection switch (Position 9 – PT-353 SW6) UP.
3.3.2.8 FEC – Forward Error Correction (Position 9 – PR-353 SW2)
The PT/PR-353 module uses powerful Reed Solomon FEC to correct for errors that may occur in
network transmission. Set the FEC selection switch (Position 9 – PR-353) DOWN to use this feature.
Note: We recommend that FEC be enabled at all times when operating the PT/PR-353 modules.
3.3.2.9 ASRC (Position 10 – PT-353 SW6)
The digital audio sample rate can be locked to the source by disabling the Asynchronous Sample Rate
Converter (ASRC), (Position 10 – PT-353 SW6), provided the incoming rate is within 100 ppm of the
configured board rate. This causes the AES transport stream to lock to the incoming AES clock, which
is not tied to the transport system clock.
Warning! Be sure the DIP switches for the sampling rate on both the PT-353 and the PR-353
modules are set to match the source sampling rate.
3.3.2.10 SPARE (Positions 5, 7, and 10 – PR-353 SW2)
These switches are spare at this time and must be UP. Verify that the spare switches on the receiver
are UP: SP4, SP5, and SP6 (Positions 5, 7, and 10 – PR-353 SW2).