24
Rev 1.7 • 18 Aug 10
3. Detail
Expansion
A frame expansion card multiplexes (TDM) the local frames inputs and sends them out the frame
expansion “Out” port to the other frame. It receives the other frame’s inputs from the “In” port.
Connect the primary input on the master frame to the slave frame’s primary output. Connect the
primary output on the master frame to the primary input on the slave frame. If you have a redundant
expansion card, connect the secondary expansion connections the same as the primary connections.
The expansion cards have built-in redundancy control. Each card reports its own health to the other
card and to the router control card. The first healthy card to start up during initial boot takes over
the expansion link and is the main transmitter and receiver. If, at any time, the link becomes
“unhealthy,” the other expansion card takes over the expansion link if it is healthy.
You can use 75
Ω
Belden 8281 cable, up to 250 meters, to make these connections.
The Expansion Card
The NV5256 has 2 slots for expansion cards. A stand-alone router requires no expansion card. One
card is required for expansion. The second expansion card provides redundancy.
Release Switch
An expansion card has a front panel reset switch. It forces the active card to release, so that the
other expansion card can take over.
LEDs
Three leds are on the front of the card. Their name and functionality are as follows:
A red ‘serial link error’ LED is in the center of the card. This LED indicates whether the frame
TDM link is invalid (has data bit errors).
Clock Lock
For the expanded router to operate correctly, the frames must be “clock-locked” to each other. The
following is a list of ways to accomplish the clock locked frames.
1 Supply an AES reference to both frames.
2 Connect the primary AES reference output on the master frame to the primary AES reference
input of the slave frame. If you have a redundant expansion card, connect the secondary AES
reference output of the master frame to the second AES reference input of the slave frame.
The video reference does
not
lock the cards.
If the frames are not clock-locked, data errors will occur when the router uses ports across video
frame boundaries.
Name
Function
Alarm
Indicates when the serial link is not error-free or the P.S. is bad.
Active
Indicates the card is healthy and supplying the Frame TDM stream to the frame.
Health
Indicates Good power, Good Serial link, FPGA loaded
