Chapter 1: Introduction1-42E43-51/2E43-51R User’s GuideThe 2E43-51R has two power supplies. The power supplies load share50% (+/-5%) of the power required by the device. If one power supplyfails, the remaining power supply assumes the entire load of the devicewithout interruption to network traffic. Each power supply modulesupports its own ac input connection, which allows the user to connecteach power supply to a different ac power circuit.1.3.1 ConnectivityThe 2E43-51 connects to Ethernet networks or workstations through four50-pin RJ21 connectors. Each connector serves as a 12-port Ethernet10 Mbps MicroLAN.Both of the devices have two front panel slots (ports 5 and 6) for optionalFast Ethernet Interface Modules to support an uplink to 100 Mbps FastEthernet backbones or a high speed connection to a local server. There isalso space for an optional HSIM to provide additional connectivity tovarious networking technologies.1.3.2 Full Duplex Switched EthernetThe optional Fast Ethernet Interface Modules for the 2E43-51 can beconfigured to operate in Full Duplex Switched Ethernet mode, whichprovides 200 Mbps of bandwidth.1.3.3 Auto-NegotiationThe repeater ports and Fast Ethernet Interface Modules can auto-negotiatethe type of connection required to provide a link to another device.During Auto-Negotiation, two devices automatically exchangeinformation “telling” each other what their operating capabilities are. TheAuto-Negotiation feature targets the maximum capabilities that can bereached between the two devices. For example, an FE-100TX FastEthernet Interface Module in a 2E43-51 can adjust to 100 Mbps when thedevice on the other end of the connection can also adjust to 100 Mbps. Ifthe device on the other end of the connection can only operate at10 Mbps, then the FE-100TX simply adjusts to 10 Mbps operation.
