Technical data

LED Indicators
14-Slot Shelf
Chapter 2
105
Hardware Redundancy Interface
The Shelf Manager supports redundant operation with automatic switchover using redundant Shelf
Managers. In a configuration where two Shelf Manager are present, one acts as the active Shelf Manager and
the other as a standby. The Shelf Managers monitor each other and either can trigger a switchover if
necessary.
The hardware redundancy interfaces of the Shelf Managers are as follows:
• Cross connected Shelf Manger present input (PRES_1#) and output (PRES_GND#).
• Cross connected Shelf Manger present input (PRES_1#) and output (PRES_GND#).
• Cross connected Shelf Manager health input (HLY_Input#) and output (HLY_Output#).
• Cross connected negotiation input (SWR_Input#) and output (SWR_Output#).²Active output from the
ShMM-500 (ACTIVE#) that is used by the ShMM-ACB-IV to enable interfaces that must be exclusively
driven by the active Shelf Manager, specifically PWM and fan tachometer buffers.
• Two status LEDs using the SWS_LED_G# (Green) and SWS_LED_R# (Red) signals.
• The PRES_1# signal is grounded on the redundant Shelf Manager. This indicates both Shelf Managers
the presence of the other.
Figure 2-16 shows the hardware redundancy interface of the
ShMM-ACB-IV.
Figure 2-16 Shelf Manager Redundancy Control