3Com 3226 User Manual

Contents

24 CHAPTER 2: INSTALLING THE SWITCHCAUTION The Switch has no ON/OFF switch; the only method ofconnecting or disconnecting mains power is by connecting ordisconnecting the power cord.Connecting aRedundant PowerSystemYou can connect a SuperStack 3 Advanced Redundant Power System tothe Switch. This unit, which is also known as an RPS, is designed tomaintain the power to your Switch if a power supply failure occurs.For normal redundancy, the unit requires one Type 3 Power Module (partnumber 3C16075).For full redundancy, the unit requires two Type 3 Power Modulescombined using a Type 3 Y-Cable (part number 3C16077).WARNING: If you are connecting the Switch to a Type 3 Power Module,read the Safety Information section in the Type 3 Power Module UserGuide.CAUTION: The Switch can only use a SuperStack Advanced RedundantPower System output.CAUTION: The Switch has no ON/OFF switch; the only method ofconnecting or disconnecting mains power is by connecting ordisconnecting the power cord.Choosing the CorrectCablesAll of the ports on the Switch are Auto-MDIX, that is they have across-over capability. The port can automatically detect whether it needsto operate in MDI or MDIX mode. Therefore you can make a connectionto a port with a straight-through (MDI) or a cross-over cable (MDIX).The Auto-MDIX feature only operates when auto-negotiation is enabled.If auto-negotiation is disabled, all the Switch ports are configured asMDIX (cross-over). If you want to make a connection to another MDIXport, you need a cross-over cable. Many ports on workstations andservers are configured as MDI (straight-through). If you want to make aconnection to an MDI port, you need to use a standard straight-throughcable. See Table 7.3Com recommends that you use Category 5 twisted pair cable — themaximum segment length for this type of cable is 100 m (328 ft).DUA1750-0AAA01.book Page 24 Friday, December 5, 2003 10:24 AM