Features
1-6 Introduction
The S-FAN Chassis Cooling System
The S4 chassis features a removable fan tray that is accessible from the front of the chassis. This 
unit is hot swappable, which allows it to be replaced without powering down the chassis. The fan 
tray has one LED located on the front of the unit. This LED indicates the status of the fan tray 
(normal/fault/not installed). Refer to “S-FAN Fan Tray Status LED” on page 3-29 for a full 
description of the fan tray LED states.
Standalone or Rack Mountable Chassis
The S4 chassis can be installed as a freestanding unit on a shelf or table. The S4 chassis can also be 
mounted into a standard 48.26-centimeter (19-inch) equipment rack. In a rack installation, the S4 
chassis can be either front mounted or mid-mounted. To mid-mount an S4 chassis, you must use 
the S-Series mid-mount brackets (S4-MIDMOUNT-KIT) that are available separately. Refer to 
“Precautions” on page 2-2 for requirements on ventilation and cooling.
RJ45 COM Ports
In the S4 chassis, the RJ45 COM ports are designed for accessing specific I/O fabric modules. For a 
particular COM port to be functional, an I/O fabric module must be present in the corresponding 
slot. In the S4 chassis, the COM ports correspond to slots 2 and 3.
USB Ports
The USB ports on the S4 chassis allow you to use a USB drive to upgrade the chassis and upload 
and download files, such as configuration files and firmware images. A USB port, however, 
functions only if an I/O fabric module is present in the corresponding slot. In the S4 chassis, the 
USB ports correspond to slots 2 and 3. For information on connecting to the USB port, refer to the 
Enterasys S-Series CLI Reference Guide.
Power over Ethernet (PoE)
The S4 chassis provides PoE to powered devices (PDs) using the PoE subsystem installed on top of 
the S-Series chassis. The PoE subsystem can support four S-POE-PS power supplies, providing up 
to 8,000W of PoE power. In a fully populated S4 chassis, PoE power can be delivered to PDs on all 
ports simultaneously. 
The S-POE-PS power supply features include the following:
• Hot swappable capability as long as the total power needed does not exceed the power output 
capability of the remaining S-POE-PSs in the PoE subsystem.
• Provides a maximum power output of 1200W (low line) or 2000W (high line) to each S-Series 
module that supports PoE. The maximum number of PDs (powered devices) supported by 
each PoE S-Series module is dependent on the PD power consumption as indicated by their 
Power Classifications. 
• Provides power redundancy when two or more S-POE-PSs are installed in the PoE subsystem 
and there is no more than a 1200W (low line) or 2000W (high line) demand by the connected 
S-Series modules to support PDs. If one S-POE-PS fails or is removed from the PoE subsystem, 
the other S-POE-PSs can support the total load.