Grass Valley VM 3000 System Controllers v.7.4 - Manual (Page 710)

Redundant VM/SI
K−2 VM 3000 Installation and Operating Manual
Setting Up a System−Loaded VM/SI
(Redundant VM/SI installation was discussed on page 2−4.)
VM/SI 3000s can be installed as a redundant pair, so that failure of one unit will result in control being taken by the second.
A third unit can be system−loaded and its address altered to provide redundancy in case one of the first two units fails. See
Figure K−2.
Figure K−2. A system−loaded VM (or SI) can be
kept on the LAN, ready to swap with a failed unit.
Redundancy Cable
LAN
Primary VM 3000
Serial control
splitter cable
House sync
House time
code
CB−3000
Crosspoint bus
Backup VM 3000
Replacement VM 3000
Although a “blank” VM/SI 3000 controller could be used for this purpose, such a unit would require a complete system and
configuration download after installation—during which time no switching or machine control commands could be issued.
(It is not possible to download only to a new, unconfigured unit, because copies of address tables are kept in all controllers
and these tables must remain identical.) To minimize potential disruption the following scheme is suggested:
1. Set the user−defined hardware addresses.