4RF Aprisa SR+ User Manual - page 31
28 | Product Options
Aprisa SR User Manual
Protected Station
The Aprisa SR Protected Station provides radio and user interface protection for Aprisa SR radios when
configured as a Base Station. 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.
Option Example
Part Number
Aprisa SR Radio
APSR-N400-012-SO-12-ETAA
Aprisa SR Protected Station
APSR-R400-012-SO-12-ETAA
The Aprisa SR Protected Station is comprised of an Aprisa SR Protection Switch and two standard Aprisa SR
radios. 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.
The active radio sends regular ‘keep alive’ messages to the standby radio to indicate it is 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