8M083X25 R14
APX Series P25 Interface
DVRS Installation & Programming Guide
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PART II
January 2019
Page 120 of 153
Analog Audio Buffering
Audio buffering is supported by the DVRS in order to eliminate loss of messages / parts
of messages due to the inherent delays associated with acquiring system access. The
analog buffer is programmable in the DVR (up to 1300ms).
Tactical Public Safety (TPS)
The Tactical Public Safety (TPS) feature allows analog subscribers to send digital PTT ID
information on an analog channel with analog voice. TPS is only supported when the DVR
is on an analog channel in the SYSTEM mode and the MSU is configured for analog
transmit (without any signaling) and with mixed receive.
Fireground (FG) Signaling
The Fireground deployment consists of a fleet of subscribers communicating with an
incident commander position using digital signaling and either analog or digital voice.
If Fireground (FG) signaling is enabled in the local PSUs and on the selected full duplex
DVRS channel, the DVR repeats locally the FG messages received from the local PSUs
to the FG terminal. FG Emergency signaling received from the local PSU can be either
repeated locally, sent to the system or both (as programmed in the DVR).
NOTE:
Only Generic P25 PSUs support Fireground operation.
Remote DVRS Activation via DTMF
The local PSU may be programmed to remotely activate the DVR by switching it from OFF
or LOCAL to SYSTEM mode by sending a pre-programmed DTMF sequence (refer to
Analog Setup
screen in Tweaker for DVRS programming instructions related to this
feature).
The remote activation only works if the local PSU and the DVR are set to operate on the
same radio channel and there is no other Primary / Permanent Primary DVR in the area
operating on the same channel.
NOTE:
The DVR cannot be switched OFF remotely via DTMF.
