GYDA-SC
Rev.
4
4
Connections
4.1
Connecting several sub-racks together
Several sub-racks can be connected to each other through the RS-422 ports
on the rear of each sub-rack.
One GYDA-SC controller can control maximum 8 sub-racks.
You start with the sub-rack containing the GYDA-SC Rack System Controller,
and use 1 RS-422 port to loop through to the next.
The last sub-rack connected must be terminated with 110
Ω
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 sub-racks.
Figure 5 shows an example of how to connect 8 sub-racks together as seen
from the rear end. By using the RS-422 interface at the GYDA-SC controller
card, we control 8 sub-racks via one RS-422 bus.
Figure 5: Control of 8 sub-racks with GYDA-SC.
The 110
Ω
termination plug used is a standard RJ45 plug with the following
internal wiring:
1 2 3 6
Figure 6: RS-422 termination.
In the figure above, Pin 1 is connected to Pin 2 with a 110
Ω
resistor, and Pin 3
is connected to Pin 6 with a 110
Ω
resistor.
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