Futurecom PDR8000 Programming Manual page 63

PL and DPL codes are predefined in a common way, to allow use across radios manufactured by multiple
vendors. The Rx and Tx squelch code entries in the table can be set to a defined PL Code, a defined DPL
Code, or set to OFF (Carrier Squelch operation).
Squelch Tail Elimination is a method used to prevent the receiving radio from hearing a brief noise
(squelch tail) at the end of each transmission. By having the transmitter provide a phase-shifted signal
(for PL), or a specific tone (for DPL), the receiver can quickly detect the end of the transmitted signal and
mute the unwanted noise. When PL is used, Tx STE and Rx STE can be set to Off, -135° phase shift,
+135° phase shift, or -180° phase shift. When DPL is used, Tx STE and Rx STE can be set to either Off or
DPL (enabled).
Multi-Coded Squelch: Normal (Multi-PL/DPL not enabled)
If the active PDR8000 channel is configured to use an Analog Code Table for Normal PL/DPL operation,
then the first row of the PL/DPL table is enabled. That row defines the Tx and Rx behavior associated
with all traffic on the channel.
The PDR8000 only processes analog signals received over the air with PL or DPL that is equal to the Rx
PL/DPL code entry found in the first row of the table. In the first row, if the Rx Squelch Code is set to OFF
(Carrier Squelch), then all received signals on that channel that meet the Signal Strength and/or Signal
Quality criteria (See Section 2.7.1.2) defined for this channel are processed by the PDR8000 (i.e. no
PL/DPL filtering is done). Received signals not meeting the strength/quality criteria are ignored.
PDR8000's Rx STE should be set to match the Tx STE sent by the subscriber units.
When the PDR8000 sends a transmission, it encodes Tx Squelch Code configured in the first row of the
Analog Code table. At the end of the transmission, PDR8000 can be configured to send a configured STE
(Squelch Tail Elimination) signal to help receiving radios quickly mute at the end of the transmission.
The configuration for Tx STE should be set to match the Rx STE expected by the subscriber units.
Multi-Coded Squelch: Multi-PL/DPL
If the active PDR8000 channel is configured to use an Analog Code Table configured for Multi-PL/DPL
operation, then the PDR8000 utilizes the full table to define filtering and translation. The PDR8000 only
processes analog signals received over the air with PL or DPL that is equal to any of the Rx PL/DPL code
entries found in any enabled row of the table. PDR8000's Rx STE in that row of the table should be set
to match the Tx STE sent by the subscriber units.
When the PDR8000 repeats an over-the-air analog transmission it encodes the Tx PL/DPL found in the
same table row as the received signal's Rx PL/DPL. At the end of the transmission, PDR8000 can be
configured to send a configured STE (Squelch Tail Elimination) signal to help receiving radios quickly
mute at the end of the transmission. The configuration for Tx STE should be set to match the Rx STE
expected by the subscriber units.
2021-11-0
PDR8000® Portable Digital Repeater Programming Guide
8K088X04 R5.00
Page 63 of 98