User's Manual

4. If the VRS does detect another VRS system repeating within the delay state, it
will stop the countdown process and stay non-priority.
5. If the VRS detects a portable frequency signal with proper PL while receiving a
repeatable base signal, it will handle it according to the portable-to-base case.
ICM Non-Priority Operation
The ICM feature will continue to operate as described in the "ICM Functions" section
except for the following:
1. While receiving a portable transmission with correct repeat qualifiers, the unit
will not repeat as long as the unit is non-priority.
2. During a portable-to-base transmission with correct PL, the non-priority VRS will
steer the mobile to the mode programmed for that PL frequency. This allows the mobile
to monitor for priority repeater traffic.
Emergency
Emergency Feature Summary
An emergency alarm is initiated when the VRS receives a portable transmission which
contains the Emergency Alarm PL, as programmed in the mode-steering screen of CPS.
Upon decoding the Emergency Alarm PL, the VRS sends an "enter emergency" bus
message to the mobile radio. The mobile radio will respond as if the Emer button had
been pressed on the control head, and will proceed with the Emergency operation which
is programmed by the CPS.
In addition, an "emergency acknowledgment" tone is transmitted by the priority VRS as
part of the automatic multi-unit priority resolution algorithm. The "Emergency ACK"
tone generated by the VRS is a 1250 Hz tone lasting 500 ms in duration. Once in
Emergency Alarm, the VRS ignores subsequent portable transmissions with the
Emergency Alarm PL until the mobile exits Emergency. (The "Emergency ACK" tone,
however, will always be generated in response to each portable transmission with the
proper Emergency Alarm PL).
Emergency Call and VRS are mutually exclusive. Even if the mobile is programmed for
alarm and call, when the alarm case is exited, the mobile will not transition into
Emergency Call while the VRS is activated. Likewise, if the mobile is in Emergency
Call, the VRS cannot be activated.
Emergency Feature Operation
Whether the mobile is programmed for silent or non-silent alarm is transparent to the
VRS. However, the Emergency Alarm sequence changes slightly between the silent and
non-silent case. The main differences are listed below:
1. The alarm exit sequence
For non-silent alarm, any of the following will cause the mobile to exit
Emergency:
o Extended keypress of the Emer button on the mobile's control head.
o Mobile microphone PTT or a portable-to-base repeat.
o Mobile exhausts its retries without receiving an "Emergency ACK" from the base.
o The mobile receives an "Emergency ACK" from the base.