Grass Valley VM 3000 System Controllers v.7.4 - Manual (Page 164)

Hardware Installation
2−92 VM 3000 Installation and Operating Manual
ESbus Installation Notes
ESbus VTRs can be connected in loop−through fashion to a single port of a VM/SI 3000 (ESbus multipoint scheme), or, to
individual ports of the VM/SI 3000 (ESbus point−to−point scheme). As stated in the ESbus specification:
The point−to−point configuration has the advantage of speed since the dedicated buses provide access to all tributaries [control
panels and machines] simultaneously. The multipoint configuration has the advantage of reduced cabling costs and complex-
ity but has the main disadvantage that messages to different tributaries must queue up and be sent serially on the bus. These
configurations are therefore slower in response time than point−to−point systems.
The optimum configuration for any local network, and the number of tributaries which it can serve, will depend critically on
the types of equipment controlled, typical message lengths and the required response time. In general the number of tributaries
would probably be in single figures.
If single−frame accuracy is required for ESbus VTRs, Grass Valley recommends setting aside an individual port on the VM/SI
3000 for each machine.
Other VTRs
Some VTRs not described above use the Sony Serial protocol; still others can be connected to the Jupiter system through a
parallel interface such as the MI−3040. Please contact Grass Valley for additional information.
INSTALLING REDUNDANT SI 3000 CONTROL SYSTEM
In a redundant installation, each SI 3000 monitors the other. If a fault is detected in the active unit, control will be switched
to the other device automatically. For information about manual changeover, and maintaining a third unit as a replacement
for a failed redundant unit, see Appendix K. Wiring for redundant SI 3000s is shown in Figure 2−107. For software configura-
tion, see Step 4 on page 5−23.
Note: Only late−model SI 3000 Control Processors can be operated in redundant mode. Please contact Grass Valley
for additional information.