4RF Aprisa SR+ User Manual - page 30
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Aprisa SR User Manual
Protected Station
The Aprisa SR Protected Station provides radio and user interface protection for Aprisa SR radios. The RF
ports and interface ports from two standard Aprisa SR Radios are switched to the standby radio if there is
a failure in the active radio.
Example Part:
Part Number
Part Description
APSR-R400-012-SO-12-ETAA
4RF SR, PS, 400-470 MHz, 12.5 kHz, SO, 12 VDC, ET, AA
The Aprisa SR Protected Station is comprised of an Aprisa SR Protection Switch and two standard Aprisa SR
radios. This configuration provides the ability to ‘hot-swap’ a failed radio without interrupting user traffic
on the active radio. Additionally, retains the full temperature range specification of a single radio.
The Aprisa SR radios can be any of the currently available Aprisa SR radio frequency bands, channel sizes
or single / dual antenna port options.
By default, the Aprisa SR Protected Station is configured with the left hand radio (A) designated as the
primary radio and the right hand radio (B) designated as the secondary radio. Each radio is configured with
its own unique IP and MAC address and the address of the partner radio.
On power-up, the primary radio will assume the active role and the secondary radio will assume the
standby role. If, for some reason, only one radio is powered on it will automatically assume the active
role.
Operation
In normal operation, the active radio carries all RS-232 serial and Ethernet traffic over the radio link and
the standby radio is unused with its transmitter turned off. Both radios are continually monitored for
correct operation and alarms are raised if an event occurs.
Both the active and standby radios send regular ‘keep alive’ messages to each other to indicate if they are
operating correctly. In the event of a failure on the active radio, the RF link and user interface traffic is
automatically switched to the standby radio.
The failed radio can then be replaced in the field without interrupting user traffic (see ‘Replacing a