Teledyne 6 RU Chassis, Руководство по эксплуатации

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6 RU SSPA Chassis Operations Manual 202058 REV AA 41
2.3.2.6 N+1 Control (Floating Master Mode)
This menu allows the user to set parameters relating to Floating N+1 Master operation.
This feature allows having a single point of control for an N+1 system Master Module.
When enabled, this mode will switch the N+1 Master Module serial and IP address to a
dedicated floating Master IP and serial address.
Without this function, a faulted Master Module in an N+1 system delegates its control
privileges to another unit, which has a different serial and IP address.
With this feature activated, the Master serial and IP addresses are reassigned to the
new Master Module and the former master unit restores its normal communication pa-
rameters.
This mode of operation allows having single M&C connection point bonded to a known
IP and Serial address, regardless which module in the N+1 system assumes the role of
the Master Module. In this mode, the user could maintain a remote connection to a sin-
gle Master unit. Simultaneous connections to other modules is optional.
If Floating Master mode is disabled, the N+1 Master unit responds to its unique IP and
serial address rather than to a dedicated master address. In this mode, simultaneous
connection to all N+1 units in the system is the most appropriate method of remote
control operation.
Floating Master mode could be used over both RS-485 and IP network. Communica-
tion over a RS-485 network requires the assignment of a unique Master serial address.
The module currently assigned as the Master Module will also respond to queries on
its own serial address.
When this mode is used over an IP network, certain factors need to be considered:
•
The Master IP address must be a unique address, not used anywhere
else on the network;
•
When Floating Master mode is active, the Master Module will stop re-
sponding on its individual IP address and start responding on Master IP
address. Should the Master Module assume slave mode (and another
unit is assigned the Master privileges), the former Master unit responds
to its individual IP address;
•
The Master address should be selected from same subnet mask and use
the same gateway address as the rest of the N+1 units in the system;
•
During the switchover process from a unit’s normal IP address and Mas-
ter address and back, the SSPA unit will execute a “gratuitous ARP” re-
quest to a network. The operator needs to make sure that the network
equipment connected to the system supports dynamic ARP tables which
may be updated by “gratuitous ARP”. Consult your network administrator;