Grass Valley VM 3000 System Controllers v.7.4 - Manual (Page 83)

Hardware Installation
2−11 VM 3000 Installation and Operating Manual
CB 3000 Control Buffer
Figure 2−10. CB 3000.
SELECT
A
SELECT
B
CLEAR
A
POWER
B
POWER
REM/ALM
OUTPUT
(CONTROL)
BUSES
CROSSPOINT
BUS LOOP
The CB 3000 Control Buffer is required for buffering crosspoint data when more than 50 TVS/TAS 3000 or TVS/TAS 2000
matrix boards (or more than 96 Venus crosspoint boards) are installed in a switching matrix. A CB 3000 is also required if
the Crosspoint Bus is sent to more than one equipment rack. Each of the eight CB 3000 outputs can drive up to 50 (TVS/TAS)
or up to 96 (Venus) crosspoint boards. See page 2−3.
For Trinix requirements, please refer to the “Planning Guide” section of the Trinix Installation Manual.
Apex audio routers do not require a CB 3000—regardless of system expansion—because the crosspoint bus is connected only
to one chassis.
Some systems may be equipped with one or more single−output CB 2000 Control Buffers rather than a CB 3000. Please refer
to the wiring information supplied with your switcher for details.
Each CB 3000 output contains two identical channels, with channel A normally used; this condition is indicated by the eight
green LEDs in the display window. If a fault is detected in channel A, that output will automatically switch to channel B; in
this case the green LEDs would be off and one or more red LEDs would be on. If a changeover occurs, first check to see if
the unit will return to normal operation by pressing the SELECT A button:
— If the unit returns to channel A operation, but a red LED remains on, press CLEAR. If the red LED(s) go off, it
can be assumed that the unit is fully operational.
— If the unit immediately returns to channel B operation, contact Grass Valley Technical Support.
For a description of the front panel window LEDs, see Appendix R.
VDE EMI/RFI Modifications to Matrix Cables
User−supplied matrix cables for VDE installations require a ferrite core over each end of the cable, adjacent to the connector.
Figure 2−11. Matrix cable VDE modifications.
Type 43 material
0.375 inch (9.53 mm) or larger inside diameter
0.95 inch (24.13 mm) length (or longer)
Type 43 material sources
Fair−Rite, part no. 2643625102
Fair−Rite Products Corp., P.O. Box J, Commercial
Row, Wallkill, NY 12589, USA; Tel. (914) 895−2055.
Chomerics, part no. 83−10−A637−1000
Chomerics Inc., 77 Dragon Ct., Woburn, MA 01888
USA; Tel. (617) 935−4850.