Teledyne HPAC-2005, Operation Manual

Page: 77 / 156

3 RU SSPA Chassis Operations Manual 205356 REV T 77
3.2 Changing N+1 Hierarchy
Normally, the hierarchical structure of the N+1 array must be set during initial system
setup. However, the operator may change the N+1 addressing hierarchy at any time.
To ensure uninterruptible system operation during such system maintenance, certain
procedural steps must be followed.
3.2.1 Changing Hierarchical Order of Slave Units
To change the hierarchical order of N+1 slave units without interrupting the system
operation:
Important! The Master unit will lose sight of one of the slave units
for the duration of this procedure. If the system is in Auto Gain
mode, this condition will cause gain overshoot. Temporarily turn off
the Auto Gain feature.
1. Turn off Auto Gain setting if needed.
2. For the first slave unit, temporarily select an N+1 address setting outside the
maximum address for the current N+1 array. For example, in a system of
4 units, select address 5 or above; for a system of 8 units, select address
9 or above; etc.
3. For the second slave unit, change its N+1 address to match the previous
N+1 address of the first unit.
4. Change the N+1 address of the first slave unit to match the previous N+1
address of the second unit.
5. System addressing hierarchy is now exchanged between first and second
unit. Turn on Auto Gain option if required.
3.2.2 Exchange N+1 Privileges Between Master and Slave Units
To delegate master privileges to a slave unit without interrupting system operation:
1. On the slave unit intended to be set as new Master unit, set the N+1 address
value to “0”. Assuming the unit is free from internal faults, the unit will
instantly change its mode to Master.
2. On the former Master unit, select its N+1 address to match the address of
the former slave unit.
3. On the new Master unit, change the N+1 address value from “0” to the
address value of the former Master unit.