8A083X30 Rev.11
APX Series P25 Interface
DVRS
User’s Guide
January 2019
Page 83 of 94
Mixed DVRS Mode
Mixed DVR mode allows analog DVR operation by switching between digital and analog
modes as described below. The use of mixed mode for analog DVRS communications is
not recommended since it requires special user training to be able to handle the DVR
switching between default digital and temporary analog mode as described below.
Mixed DVR mode should only be used when both analog and digital PSUs are required
to operate on the same DVR channel. Mixed DVRS mode requires the MSU to be
switched to a P25 Digital channel. When a DVR channel is programmed to operate in
mixed mode, the DVRS can handle calls from both P25 and analog local PSUs while the
same DVR channel is selected on the MSU.
When mixed mode is selected, the DVR can be toggled between digital and analog
mode as follows:
•
The default DVRS mode is digital i.e. the P25 modem is enabled by default.
•
If a call from a local PSU is detected and the DVR does not decode a P25 frame
sync within the preprogrammed
‘P25 Frame Sync Detection Timer’
, the DVR
switches to analog mode and starts decoding analog mode signaling (such as
DTMF, MDC1200). The DVR repeats analog signals to the local analog PSUs
and system MSUs / PSUs on the selected system channel / TG.
•
After the local PSU keys off, the DVR stays in the analog mode for the duration
of the preprogrammed
‘VR Ch Mixed Mode Hold Timer’.
Any outbound calls
which are received by the MSU prior to the abov
e timer’s expiration will be
repeated by the DVR as analog conventional.
•
Once the
‘VR Ch Mixed Mode Hold Timer’
expires, the DVR returns back to
digital mode and any outbound calls are repeated as digital. Inbound analog
calls received by the DVR in mixed mode are repeated to the system by the MSU
on the selected TG / Channel.
•
If TG Proxying is enabled, digital inbound calls received by the DVR are
transmitted by the MSU on the TG selected on the local PSU (not on the TG
selected on the MSU).
