Nevion FR202 - Manual (Page 13)

FR-2RU-20-2 Rev. A
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4.3.2 Connecting several frames together
Several frames can be connected to each other through the RS-422 ports on the rear of
each frame.
One GYDA-SC controller can control maximum 8 frames.
You start with the frame containing the GYDA-SC Rack System Controller, and use 1 RS-
422 port to loop through to the next.
The last frame connected must be terminated with 110

in order to ensure proper
operation. The other port of the rack containing the GYDA-SC controller must be left open,
and cannot be connected to other frames.
Figure 5 shows an example of how to connect 8 frames together as seen from the rear end.
By using the RS-422 interface at the GYDA-SC controller card, we control 8 frames via one
RS-422 bus.
Figure 9: Control of 8 frames with GYDA-SC.
The 110

termination plug used is a standard RJ45 plug with the following internal wiring:
Figure 10: RS-422 termination.
In the figure above, Pin 1 is connected to Pin 2 with a 110

resistor, and Pin 3 is connected
to Pin 6 with a 110

resistor.
1 2 3 6