Technical data

LED Indicators
14-Slot Shelf
Chapter 2
96
These signals are controlled by the PCA9555 I²C device on the Fan Tray PCB. The Shelf Manager has access
to these signals via Channel 3 of the Master-Only I²C-bus. The fan signals are shown in Table 2-11, and
Figure 2-11.
Figure 2-11 Fan Tray Block Diagram
Table 2-11 Fan Tray Signals
Signal Description
-48 V_A bus voltage Indicates the presence of the -48 V_A/VRTN_A at the Horizontal Board Connector.
-48 V_A fan tray voltage Indicates the presence of the -48 V_A/VRTN_A after the fan tray’s main fuse.
-48 V_B bus voltage Indicates the presence of the -48 V_B/VRTN_B at the Horizontal Board Connector.
-48 V_B fan tray voltage Indicates the presence of the -48 V_B/VRTN_B after the fan tray’s main fuse.
DC/DC OK Indicates the proper functioning of the DC-DC converter that generates the 24 V
voltage supply.
Fan Off Turns off the fans.