Motorola VRS750, Service Manual

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3. Upon reaching delay state 0, the non-priority VRS will become
the priority VRS and start repeating. The maximum delay for a
non-priority VRS to countdown into priority is 3.4 seconds for
conventional and 5.8 seconds for trunking.
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.