FR-2RU-10-2
Rev.
8
9
4.1.2
GPI Power Supply Status outputs
The GPI module status outputs can be used for wiring up alarms for third
party control systems.
In case of power failure, pins 3 and 7 will be physically connected (low
impedance), otherwise the connection between pins 3 and 7 will be high
impedance.
4.2
RS-422 connection
At the rear end of the sub-rack is an RS-422 bus. When used in combination
with the GYDA-SC Rack System Controller, up to 8 sub-racks can be
controlled. On the rear end of the sub-rack are DIP-switches where each sub-
rack can be assigned its own address (see figure 3).
The RS-422 interfaces are shown in figure 3.
4.2.1
Pin-out RS-422 (RJ45)
Pin #1
Rx A (+)
Pin #2
Rx B (-)
Pin #3
Tx A (+)
Pin #4
Reserved
Pin #5
Reserved
Pin #6
Tx B (-)
Pin #7
Not Connected
Pin #8
Not Connected
Figure 4: RS-422 pin-out.
4.2.2
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.
