4RF Aprisa SR+ User Manual - page 33
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Aprisa SR User Manual
Hardware Manual Lock
The Hardware Manual Lock switch on the Protection Switch provides a manual override of the active /
standby radio.
When this lock is activated, the selected radio (A or B) becomes the active radio regardless of the
Software Manual Lock and the current switching or block criteria.
When the lock is deactivated (set to the Auto position), the protection will become automatic and
switching will be governed by normal switching and blocking criteria.
The state of the lock is indicated by the three LEDs on the Protection Switch:
A LED Orange
Manual Lock asserted and radio A is active
B LED Orange
Manual Lock asserted and radio B is active
Auto LED Green
Manual Lock is in Auto position
Only one of three LEDs will be active at a time.
The Protection Switch also has a Software Manual Lock (see ‘Lock Active’ on page 119). The Hardware
Manual Lock takes precedence over Software Manual Lock if both diagnostic functions are activated i.e. if
the Software Manual Lock is set to ‘Primary’ and the Hardware Manual Lock set to ‘Secondary’, the system
will set the Secondary radio to Active.
When a Hardware Manual Lock is deactivated (set to the Auto position), the Software Manual Lock is re-
evaluated and locks set appropriately.
Remote Control
The switch over to the standby radio can be initiated via the Remote Control connector on the front of the
Protection Switch. This control will only operate if the Hardware Manual Lock switch is set to the Auto
position.
The inputs are logic inputs with 220 Ω pullup to +5 VDC. They require a pull down to ground to activate
the control. The ground potential is available on the connector (see ‘Protection Switch Remote Control
Connections’ on page 143).