8A083X30 Rev.11
APX Series P25 Interface
DVRS
User’s Guide
January 2019
Page 54 of 94
MSU Voice and Signaling Proxy Interactions
The MSU handles interactions with a PSU voice or signaling proxy request from the
DVR based on the following general priority rules:
•
MSU Emergency overrides all proxies including PSU emergency alarm /
emergency call.
•
PSU Emergency overrides all MSU non-emergency proxies
•
MSU PTT and signaling features (call alert, status etc) override all PSU non-
emergency proxies
•
PSU non-emergency proxies override MSU receive
Talk Group Proxying
The Local PSU User can change the select
ed ‘DVRS Enabled’ TG and seamlessly talk
to the corresponding TG users through the DVRS. The MSU can be on a
ny ‘DVRS
Enabled’ TG, which may or may not match the TG selected by the Local PSU. For
example, if the Local PSU selects TG1 while the MSU is on TG2, the Local PSU can talk
to Local TG1 users as well as System TG1 users via the DVRS i.e. the MSU will be
transmitting on TG1. If the MSU microphone is PTT-ed, both the MSU and the DVR will
transmit on the TG selected on the MSU i.e. TG2. An outbound call received by the MSU
on either TG1 or TG2 will be repeated by the DVRS to the Local PSUs.
If Proxying is disabled, then the Local PSU and the MSU must have the same TG
selected in order to enable Local PSU affiliation and communications.
Talk Group Translation
When TG translation is enabled in the DVR for a specific PSU TG ID, then any call that
is received by the DVR from the Local PSU with this TG ID will be translated to the ID of
the TG currently selected
on the MSU’s control head. The Local PSU could be
programmed with just one TG ID and if this ID is programmed in the DVRS TG
Translation list, the PSU call will always be translated by the DVRS to the TG ID
currently selected on the MSU control head. For instance, if the Local PSU is on TG A,
which is programmed in the DVRS TG Translation list and the MSU is on TG B then all
inbound Local PSU calls will be repeated by the DVR locally and to the system on TG B.
If the MSU mode is then switched to TG C then the Local PSU calls will be repeated on
TG C.
Generic (non-DVRS Enabled) Conventional P25 PSUs that are not enabled for
Talkgroup operation will, by default, use TG ID 1 when transmitting. If TG ID 1 is added
to the DVR Translation table, then PSUs transmitting TG ID 1 will be translated to the
TG selected on the MSU.
IMPORTANT!
TG Translation requires that TG Proxying is enabled.
When TG Proxying is enabled and the TG selected on the Local PSU is programmed in
the DVRS Translation Table, the DVRS will affiliate the Local PSU on the TG that is
selected on the MSU. If TG Proxying is enabled but the Local PSU is on a TG that is not
in the DVRS TG Translation list then the DVRS will proxy any inbound / outbound calls
on the PSU TG ID. Outbound call (system originated call) received on the currently
selected MSU TG is repeated ‘as is’ i.e. without any translation. Therefore the Local
